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Photosynthetic analyses of two native Atlantic Forest species in regenerative understory of eucalyptus plantation
Provedor de dados: 61
Autores: Lage-Pinto,Frederico; Bernini,Elaine; Oliveira,Jurandi Gonçalves de; Vitória,Angela Pierre.
Gas exchange, chlorophyll afluorescence, and photosynthetic pigments of Xylopia sericeaA. St.-Hil. and Siparuna guianensis Aubl. were evaluated during the rainy season and the dry season (2009-2010) in three understories with different ecological conditions (irradiance, water availability, and temperature) located in the União Biological Reserve (known as REBIO União), at Rio de Janeiro State, a natural forest understory, eucalyptus understory under regeneration, and understory of eucalyptus plantation with 18-year-old trees that were removed 1 year before. The lowest values of Fv/Fm e Fm/Fo were observed in the exposed understory for both seasons, with lower values in the dry season, suggesting that reduced water availability potentializes the...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Corymbia citriodora; Dehydration; Photoinhibition; Siparuna guianensis; Xylopia sericea.
Ano: 2012
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202012000200003

Ecophysiology of tea
Provedor de dados: 61
Autores: De Costa,W.A. Janendra M.; Mohotti,A. Janaki; Wijeratne,Madawala A.
Tea [Camellia sinensis (L.) O. Kuntze] is one of the most important beverage crops in the world. The major tea-growing regions of the world are South-East Asia and Eastern Africa where it is grown across a wide range of altitudes up to 2200 m a.s.l.. This paper reviews the key physiological processes responsible for yield determination of tea and discusses how these processes are influenced by genotypic and environmental factors. Yield formation of tea is discussed in terms of assimilate supply through photosynthesis and formation of harvestable sinks (i.e. shoots). The photosynthetic apparatus and partial processes (i.e. light capture, electron transport and carboxylation) of tea show specific adaptations to shade. Consequently, maximum light-saturated...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Climate change; Photoinhibition; Photosynthesis; Shoot growth; Temperature; Vapour pressure deficit; Water potential.
Ano: 2007
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202007000400005

Cadmium toxicity causes oxidative stress and induces response of the antioxidant system in cucumber seedlings
Provedor de dados: 61
Autores: Gonçalves,Jamile F.; Becker,Alexssandro G.; Cargnelutti,Denise; Tabaldi,Luciane A.; Pereira,Luciane B.; Battisti,Vanessa; Spanevello,Rosélia M.; Morsch,Vera M.; Nicoloso,Fernando T.; Schetinger,Maria R.C.
In this study, the effects of cadmium (Cd) on lipid peroxidation, electrolyte leakage, protein oxidation, ascorbate peroxidase (APX; E.C. 1.11.1.11), catalase (CAT; E.C. 1.11.1.6) and superoxide dismutase (SOD; E.C. 1.15.1.1) activities, and ascorbic acid, non-protein thiol groups and total soluble protein contents in cucumber seedlings (Cucumis sativus L.) were investigated. Seedlings were grown in vitro in an agar-solidified substrate containing four Cd levels as CdCl2 (0, 100, 400, and 1000 µmol L-1) for 10 d. The lowest Cd level decreased the malondialdehyde concentration. Electrolyte leakage increased only at 1000 µmol Cd L-1, whereas protein oxidation and total soluble protein content were enhanced at 400 and 1000 µmol Cd L-1. Activity of APX was...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Antioxidant enzymes; Ascorbic acid; Cucumis sativus; Heavy metal; Lipid peroxidation; Protein oxidation.
Ano: 2007
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202007000300006

Effects of in vitro triacontanol on growth, antioxidant enzymes, and photosynthetic characteristics in Arachis hypogaea L.
Provedor de dados: 61
Autores: Verma,Aman; Malik,Chander Parkash; Gupta,Vijay Kumar; Bajaj,Bhavneet Kaur.
In vitro effects of triacontanol (TRIA) on antioxidant enzymes and photosynthetic characteristics were studied in Arachis hypogaea L. cultivars (M-13 and PBS24030). The in vitro impact of TRIA on multiplication potential was also evaluated, which was found to be best at 2.0 ml L-1 TRIA in combination with 6- Benzyl adenine (BA, 3 mg L-1) in both the groundnut cultivars. Rhizogenesis was observed in almost all the TRIA treated cultures in both the cultivars. Moreover, shoots failed to set roots, in the presence of BA. Total chlorophyll content, total soluble sugars, total soluble proteins and ascorbate peroxidase (APX; EC 1.11.1.11) activity were found to be increasing with increasing concentrations of TRIA, whether alone or in combination with BA, however,...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Catalase; Groundnut; Peroxidase; Vipul.
Ano: 2011
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202011000400004

Effects of different nitrogen sources on growth, chlorophyll concentration, nitrate reductase activity and carbon and nitrogen distribution in Araucaria angustifolia
Provedor de dados: 61
Autores: Garbin,Mário L.; Dillenburg,Lúcia R.
The southern Brazilian highland plateau is a mosaic of two contrasting plant communities, Araucaria forests and grasslands, which differ in the relative abundances and spatial patterns of soil nitrate and ammonium. However, we still do not know the inorganic N preferences of one key species in this mosaic, Araucaria angustifolia, the dominant tree species in the Araucaria forests and an important tree species invading the adjacent grasslands. Growth responses measured in a greenhouse study demonstrated that the species prefers NH4+ over NO3- as an inorganic N source. When provided alone, NO3- induced N deficiency symptoms: increases in root: shoot ratio, root branching and leaf mass per area, thickening of the shoot apexes and decreased mass-based...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Araucariaceae; Ammonium; Inorganic nitrogen; Nitrate; Nitrogen deficiency.
Ano: 2008
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202008000400005

Changes in network connectance and temporal dynamics of gas exchange in Citrus sinensis under different evaporative demands
Provedor de dados: 61
Autores: Souza,Gustavo M.; Ribeiro,Rafael V.; Pincus,Steven M.
Stomatal aperture is an essential factor both in regulation of transpiration and net photosynthesis. This regulation is especially important in the response of plants to drought or to an increase in leaf-to-air vapor pressure difference (VPD); however, such a regulation is part of a complex dynamical environment, associated with multiple regulatory pathways. Accordingly, we studied the effects of VPD on gas exchange of Citrus sinensis via the evaluation of two complementary analytic approaches, to approach an understanding of the full scope of the system interactions. First, we used classical statistical methodologies, e.g., means, coefficient of variation, and linear correlation. Second, we used measures developed for more model-independent applications,...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Approximate entropy; Leaf-to-air vapor pressure difference; Network modulation; Time-series analysis.
Ano: 2004
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202004000300001

Differential activation of the enzymatic antioxidant system of Abelmoschus esculentus L. under CdCl2 and HgCl2 exposure
Provedor de dados: 61
Autores: Hameed,Asiya; Qadri,Tabasum N.; Mahmooduzzafar,; Siddiqi,T.O.; Iqbal,M.
Cadmium and Mercury induced varying responses in Abelmoschus esculentus L. in relation to enzymes (ascorbate peroxidase (APX, 1.11.1.11), catalase (CAT, 1.11.1.6), glutathione reductase (GR, 1.6.4.2) and superoxide dismutase (SOD, 1.15.1.1) which are most related to the levels of Hg and Cd applied and concentrations of thiol groups already present or induced upon treatment. In the present investigation varying concentrations of CdCl2 and HgCl2 (0, 0.05, 0.10, 0.50, 1 and 2mM respectively) applied to plant in the soil shows a significant increase in ascorbate peroxidase, glutathione reductase and superoxide dismutase activities, and the respective metal accumulation. It reveals a mechanism for constant detoxification of H2O2 that have to be associated with...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Antioxidative enzymes; Metals detoxification; Reactive oxygen species.
Ano: 2011
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202011000100007

Presence of the cytolytic protein enterolobin in different developmental stages of Enterolobium contortisiliquum seeds
Provedor de dados: 61
Autores: Lima,Consuelo M. R. de; Zanotta,Pedro J. P.; Ricart,Carlos A. O.; Sousa,Marcelo V. de.
Enterolobin is a 52.9 kDa, cytolytic, inflammatory and insecticidal protein present in Enterolobium contortisiliquum (Vell.) Morong, a Brazilian large-sized tree. This protein was previously described to occur in different forms of association (monomeric and oligomeric forms). In the current work, we investigated the presence of enterolobin forms of association and hemolytic activity in maturing, germinating and germinated seeds. Immunoblotting analysis revealed the presence of the monomeric form of enterolobin in all phases under study, whereas the dimer was detected in developing seeds in the second half of the maturation period, during germination and in the early post-germination phase. The trimeric form of enterolobin appeared one week after the dimer...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Defense proteins; Hemolytic proteins; Plant defense; Seed germination.
Ano: 2007
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202007000200008

Tropical seed species' responses to liquid nitrogen exposure
Provedor de dados: 61
Autores: Salomão,Antonieta Nassif.
The ability to tolerate ultra-low temperature (-196 ºC) exposure was evaluated in 66 tropical orthodox seed species of 21 botanical families from the Cerrado (Brazilian Savannah) and Atlantic Forest Brazilian biomes. Liquid nitrogen had no effect on the germinability of 51 seed species. The stimulatory effect of cryogenic temperature on germinability, with or without subsequent chemical scarification, was observed in nine seed species with deep physical dormancy, or heterogeneous levels of seed hardness, or with no dormancy. Significant reduction in germinability occurred in six seed species, presumably because of factors acting individually or in combination on these seeds, such as inappropriate moisture content, or the potentially detrimental effect of...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Cryopreservation; Ex situ conservation; Seed dormancy.
Ano: 2002
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202002000200008

NaCl salinity affects germination, growth, physiology, and biochemistry of bambara groundnut
Provedor de dados: 61
Autores: Ambede,Jane Gayalwa; Netondo,Godffrey Wafula; Mwai,Gideon Njau; Musyimi,David Mutisya.
The effects of NaCl salinity on seed germination, growth, physiology, and biochemistry of two bambara groundnut landraces (Vigna subterranea (L.) Verdc), Kakamega (white seed coat) and Mumias (red seed coat), were investigated with the aim of establishing traits, which can provide a basis for breeding to salt tolerance in groundnuts. A study was conducted under laboratorial and greenhouse conditions. Bambara groundnut seeds and plants were subjected to five concentrations of NaCl solutions with several electrical conductivities: 0 (control), 6.96, 12.93, 19.89, and 25.86 dS m-1. Germination percentage, growth, chlorophyll fluorescence, and leaf chlorophyll content were determined. Sodium chloride salinity (p&lt;0.05) significantly decreased germination and...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Salinity; Vigna subterranea; Growth physiology; Saline water.
Ano: 2012
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202012000300002

The effects of salt stress on growth, nitrate reduction and proline and glycinebetaine accumulation in Prosopis alba
Provedor de dados: 61
Autores: Meloni,Diego Ariel; Gulotta,Marta Rosalía; Martínez,Carlos Alberto; Oliva,Marco Antonio.
Prosopis alba (algarrobo) is one of the most important salt-tolerant legumes used in the food and furniture industries. The effects of salinity on some growth and physiological parameters in algarrrobo seedlings were investigated. 17-Day-old seedlings were subjected to three salt treatments by adding NaCl to the growth medium in 50 mmol.L-1 increments every 24 h until the final concentrations of 0, 300 and 600 mmol.L-1 were reached. Only the highest NaCl concentration affected all of the considered parameters. Thus, 600 mmol.L-1 NaCl caused a significant reduction in root and shoot growth, but an increase in the root/shoot ratio. Leaf relative water content, nitrate content and nitrate reductase activity in leaves and roots were also decreased. At 300 and...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Glycinebetaine; Nitrate reductase; Proline; Salinity.
Ano: 2004
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202004000100006

IV.Heat stress in Triticum: kinetics of Fe and Mn accumulation
Provedor de dados: 61
Autores: Dias,Ana S.; Lidon,Fernando C.; Ramalho,José C.
The interactions between Fe/Mn accumulation and the photosynthetic light reactions were investigated in heat stressed bread and durum wheat genotypes (Triticum aestivum L. and Triticum turgidum subsp.durum). Four genotypes were chosen according to its genetic background diversity. Plants were grown in a greenhouse at two different day/night temperatures regimes (control - 25/14ºC and heat stress - 31/20ºC), during the grain filling phase. The contents and uptake/translocation of Fe and Mn were evaluated on booting, grain filling and maturity and correlated with chlorophyll a fluorescence parameters. It was found that, under heat stress, the concentrations of Fe in the culm and leaves diminished in bread wheat, but increased in durum wheat. An opposite...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Heat stress; Nutrients; Translocation; Triticum aestivum L.; Triticum turgidum subsp. durum; Uptake.
Ano: 2009
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202009000200008

Gas exchange and yield response to foliar phosphorus application in Phaseolus vulgaris L. under drought
Provedor de dados: 61
Autores: Santos,Mauro Guida dos; Ribeiro,Rafael Vasconcelos; Oliveira,Ricardo Ferraz de; Pimentel,Carlos.
This study was conducted to evaluate the effect of foliar Pi application on gas exchange and yield of bean genotypes submitted to a mild water deficit at the pre-flowering stage. In the first experiment, when extra Pi (10 g.L-1) was sprayed on leaves during water stress or during recovery, there was no effect on gas exchange or yield in the A320, Carioca and Ouro Negro genotypes. However, net CO2 assimilation (A) of A320 and Ouro Negro was less affected, but not significantly, than Carioca at the end of the stress, when Pi was supplied five days before water deficit. In the second experiment, two different doses of Pi (10 and 20 g.Pi L-1) were sprayed five days before water deficit on the Carioca genotype. During the last three days of the mild water...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Common bean; Inorganic phosphorus; Photosynthesis; Water deficit.
Ano: 2004
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202004000300007

Multiple shoot formation in Hypericum perforatum L.and hypericin production
Provedor de dados: 61
Autores: Santarém,Eliane Romanato; Astarita,Leandro Vieira.
Hypericum perforatum is a traditional medicinal plant with wound healing and antidepressive properties. Among the secondary compounds of interest is hypericin, a naphtodianthrone that seems to participate in the medicinal effects of this species. The aim of this work was to obtain an efficient micropropagation system of H. perforatum and to compare the hypericin content between in vitro and field-grown plants. Cultures were initiated from nodal segments of mature plants inoculated onto MS medium supplemented with 4.5 muM BA, kinetin, thidiazuron, individually or in combination with 0.05 muM NAA. Organogenic explants were observed on medium with either BA or kinetin alone or in combination of these with NAA. Subculture of organogenic explants onto the...
Tipo: Info:eu-repo/semantics/other
Palavras-chave: Medicinal plant; Micropropagation; Organogenesis; St. John's Wort.
Ano: 2003
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202003000100006

Activity of alternative oxidase and plant uncoupling mitochondrial protein in potato tubers stored at low temperature or submitted to artificial aging
Provedor de dados: 61
Autores: Pinheiro,Hugo Alves; Borges,Regis; Silva,Marco Aurélio Pedron e; Centeno,Danilo Cruz.
Potato tubers (Solanum tuberosum L. cv. Binje) were stored at 18 and 4ºC in order to verify changes in mitochondrial metabolism, especially in the activities of the alternative oxidase (AOX) and plant uncoupling mitochondria protein (PUMP). Tubers were also sliced and submitted to artificial aging. The oxygen consumption rate (OCR), respiratory control (RC) and ADP/O ratio for mitochondria obtained after storage at 18ºC were not altered, regardless of the time of storage. Considerable increment in OCR, for both respiratory states 3 and 4, was observed after storing the tubers for five and ten days at 4ºC; and it was accomplished by reductions in RC and ADP/O. The AOX activity was evident after five days at 4ºC, and it was enhanced after ten days of storage...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Solanum tuberosum L.; Mitochondrial swelling; Oxidative stress; Respiration.
Ano: 2004
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202004000200001

Ecophysiological adaptation and metal accumulation in water hyacinth from two tropical rivers
Provedor de dados: 61
Autores: Vitória,Angela P.; Lage-Pinto,Frederico; Campaneli,Leonardo B.; Almeida,Marcelo G.; Souza,Cristina M. M.; Rezende,Carlos E.; Azevedo,Ricardo A.; Oliveira,Jurandi G.
The ecophysiological adaptations of water hyacinth (metal hyperaccumulator) under adverse environmental conditions are not yet clearly elucidated. This work evaluated photosynthetic pigments and chlorophyll a fluorescence in water hyacinth plants sampled in different regions (upper, middle and lower) of Paraíba do Sul river (PSR) and Imbé river, Brazil. Additionally Mn, Fe, Zn, Cu, Cr, Pb and Ni were quantified on the shoots and roots. Roots were the preferential site of metal accumulation. Cromium was not detected in the shoots. Iron and Mn were the elements detected in higher concentrations in all samples. Zinc and Cu were detected in higher concentrations in roots of plants from middle and upper PSR, sites of higher anthropogenic activity. The highest...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Pollution; Paraíba do Sul river; Energy dissipation; Photosynthetic pigments; Nonphotochemical quenchings.
Ano: 2010
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202010000100006

Effect of Phytoaccumulation of Arsenic and Chromium on Structural and Ultrastructural Changes of Brake Fern (Pteris vittata)
Provedor de dados: 61
Autores: Sridhar,Balaji B. Maruthi; Han,Fengxiang X.; Diehl,Susan V.; Monts,David L.; Su,Yi.
Structural and ultrastructural changes caused by bioaccumulation of As and Cr in brake fern (Pteris vittata), a known arsenic hyperaccumulator, were investigated. Potted plants of brake fern were exposed to metal treatments of As and Cr for three weeks. Leaf, stem and root samples were collected periodically and fixed for LM (Light Microscopy), SEM (Scanning Electron Microscopy) and TEM (Transmission Electron Microscopy) to evaluate anatomical changes. The fresh weights, dry weights, RWC (Relative Water Content) and plant heights were obtained before the brake fern plants were harvested for metal accumulation analysis. The As accumulated mainly in the shoots while Cr accumulated mainly in the roots of the metal-treated plants. Significant changes in the...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Anatomy; Arsenic; Chromium; Hyperaccumulator; Microscopy; Phytoremediation; Pteris vittata; Translocation; Ultrastructure.
Ano: 2011
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202011000400006

Water deficit affects photosynthetic induction in Bauhinia forficata Link (Fabaceae) and Esenbeckia leiocarpa Engl. (Rutaceae) growing in understorey and gap conditions
Provedor de dados: 61
Autores: Portes,Maria T.; Alves,Thiago H.; Souza,Gustavo M.
In tropical forests, light is considered the most limiting resource for plant growth and reproduction. Besides light, water deficit leads invariably to a decrease in photosynthesis. Thus, despite of the unquestionable role of light in CO2 assimilation (A), it is expected that water deficit affects and limits the light utilization by plants. In this study, we investigated how water deficit influenced the photosynthetic induction of the early successional tree Bauhinia forficata (Fabaceae) and the late successional Esenbeckia leiocarpa (Rutaceae) in the understorey and in the forest gap. Field measurements were carried out in June and August 2006 in plants of approximately two-years-old. In August, the plants were subjected to a period of 45 d without rain...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Drought; Ecophysiology; Gas exchange; Light utilization; Sunflecks; Tropical forest succession.
Ano: 2006
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202006000400007

Cytogenetics of coffee
Provedor de dados: 61
Autores: Pinto-Maglio,Cecília A. F.
The genus Coffea L. has around 100 native species distributed in tropical and subtropical areas in Africa, and the most important economic species are C. arabica and C. canephora. C. arabica is exceptional in the genus since it is the only species so far analyzed which is self-compatible, and a natural polyploid with 2n=4x=44 chromosomes; it is considered to be a segmental allopolyploid because it presents a disomic inheritance and a regular meiotic behavior. All other species in the genus are self-incompatible diploids with 2n=2x=22. Cytogenetic studies in Coffea, undertaken since 1912, have followed various phases: initial studies were limited only to establishing chromosome counts. Subsequent studies characterized the karyotypes of various species using...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Coffea; Chromosomal characterization; Karyotype; Meiotic behavior; Chromomere pattern; Chromosome banding; Molecular cytogenetics.
Ano: 2006
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202006000100004

Influence of chromium in Laguncularia racemosa (L). Gaertn f. physiology
Provedor de dados: 61
Autores: Rocha,Andréa C.; Canal,Emerson C.; Campostrini,Eliemar; Reis,Fabrício O.; Cuzzuol,Geraldo Rogério F.
Most studies of chromium have been realized in the sediments and in mangrove trees. However, little is known about its effect on growth and metabolism in this vegetation. L. racemosa plants were grown in solution with 20% of ionic strength of Hoagland and Arnon containing 100 mM NaCl and supplemented with 0.00, 0.05 and 0.50 mg L-1 of Cr+3. The growth, the pigments and gas exchange measurements showed no changes in response to doses of chromium. After 30 days the initiation of treatments, plants of L. racemosa had average 0.559 g of total dry weight, 1.34 mg L-1 of total chlorophyll and 7.9 µmol m-2 s-1 of A (CO2 photosynthetic assimilation). The photochemical potential efficiency was affected by the intermediate dose of 0.05 mg L-1 of Cr+3 (Fv/Fm=0.73)...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Carbohydrates; Fluorescence; Gas exchange; Growth; Heavy metal; Mangrove.
Ano: 2009
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202009000200001

Plant BiP gene family: differential expression, stress induction and protective role against physiological stresses
Provedor de dados: 61
Autores: Carolino,Sonia Madali Boseja; Vaez,Juliana Rocha; Irsigler,André Southernman Teixeira; Valente,Maria Anete S.; Rodrigues,Leonardo Augusto Zebral; Fontes,Elizabeth Pacheco Batista.
In contrast to yeast or mammalian counterpart, BiP (Binding Protein) from several plant species, such as maize, tobacco, Arabidopsis and soybean, is encoded by a multigene family. A systematic characterization and analysis of soybean BiP expression have provided evidence for the existence of multiple, complex regulatory mechanisms controlling plant BiP gene expression. In support of this observation, the soybean BiP gene family has been shown to exhibit organ-specific expression and differential regulation in response to abiotic stresses through distinct signaling pathways. As a member of the stress-regulated HSP70 family of protein, the elucidation of plant BiP function and regulation is likely to lead do new strategies to enhance crop tolerance to...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Endoplasmic reticulum; ER stressors; Grp78; Molecular chaperone; Unfolded protein response; Water stress.
Ano: 2003
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202003000200001

Morphological and physiological adjustments of Brazilwood (Caesalpinia echinata Lam.) to direct solar radiation
Provedor de dados: 61
Autores: Mengarda,Liana Hilda Golin; Milanez,Camilla Rozindo Dias; Silva,Diolina Moura; Aguilar,Marco Antonio Galeas; Cuzzuol,Geraldo Rogério Faustini.
This study aimed to characterize the alarm and resistance phases of stress of Caesalpinia echinata under intense irradiance in order to better define its position on forest succession. The alarm phase was identified by rapid reduction in the maximum quantum yield of PSII primary photochemical reactions (ΦP0 = FV/FM) and Performance Index (PIABS) followed by total leaf abscission in the first week of exposure to direct sunlight. The new leaves grown showed recovery of chlorophyll a parameters, increase in blade thickness, elongation of the palisade and spongy parenchymas, higher water content, and reduction of specific leaf area. These changes were associated with the osmoprotector of sucrose and antioxidative of raffinose effects, which indicate an...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Forest succession; Light stress; Photoinhibition; Leaf anatomy; Soluble carbohydrates.
Ano: 2012
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202012000300003

Brassinosteroid phytohormones: structure, bioactivity and applications
Provedor de dados: 61
Autores: Zullo,Marco António Teixeira; Adam,Günter.
Brassinosteroids are a new class of plant hormones with a polyoxygenated steroid structure showing pronounced plant growth regulatory activity. This review covers their natural occurrence, biological and chromatographic methods for their detection, biosynthesis and metabolism, biological activity, structure-activity relationships and prospective agricultural uses.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Brassinolide; Brassinosteroids.
Ano: 2002
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202002000300001

Brotação do rizoma de Kohleria sp
Provedor de dados: 61
Autores: Almeida,Julieta Andrea Silva de; Pereira,Maria de Fátima D. A.
O gênero Kohleria sp pertencente à família Gesneriaceae possui órgão subterrâneo. Este órgão é um caule envolto por folhas modificadas, imbricadas, as quais acumulam reservas e cada uma destas protege uma gema. Seções do rizoma brotam sem necessidade do órgão inteiro. Seções deste rizoma com seis folhas modificadas foram colocadas para brotar em placas de Petri e testadas quanto às temperaturas de 15, 20, 25, 30 e 35 ºC, na luz ou no escuro e ainda em relação aos teores de umidade do substrato, onde se adicionaram os volumes de 1, 12 e 20 mL de água destilada. Estes fatores influenciaram a brotação de seções do rizoma de Kohleria sp. As seções também se mostraram resistentes à falta de água, já que, nessa condição, apresentaram brotações e ainda as...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Gema; Luz; Temperatura; Tempo de brotação; Teor de umidade.
Ano: 2002
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202002000100006

Purification and characterization of trypsin inhibitor from Cicer arietinum L. and its efficacy against Helicoverpa armigera
Provedor de dados: 61
Autores: Kansal,Rekha; Kumar,Mukesh; Kuhar,Kalika; Gupta,Ram N.; Subrahmanyam,Bhattiprolu; Koundal,Kirpa R.; Gupta,Vijay K.
Protease inhibitors in legumes are one of the most promising weapons that confer resistance against insects by inhibiting proteases present in the gut of insect larvae. In the present study, trypsin inhibitor activity was detected in the seed flour extracts of 10 selected varieties of chickpea. The presence of inhibitor was confirmed by dot blot analysis. All the varieties showed inhibitory activity in vitro against the gut protease of Helicoverpa armigera (HGP). Trypsin inhibitor has been purified to near homogeneity to 60.46 fold and 29.20% recovery from chickpea seeds using heat denaturation, ammonium sulphate fractionation, DEAE-Sephadex A-25 and Sephadex G-75. The purified inhibitor showed a single band on SDS-PAGE corresponding to molecular mass of...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Chickpea; Dot blot; Insect bioassay; PH stability; Thermostability.
Ano: 2008
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202008000400007

Leaf and fruiting phenology and gas exchange of Mangabeira in response to irrigation
Provedor de dados: 61
Autores: Lobo,Francisco de A.; Campelo Junior,José H.; Rodríguez-Ortíz,Carmen E.; Lucena,Isabela C. de; Vourlitis,George L.
The mangabeira (Hancornia speciosa Gómez) is a native species of Brazil occurring in the savanna (Cerrado) and Atlantic Coastal forests. It is a promising species for large-scale horticulture due to the high-protein properties of its fruits, but extensive cultivation has not yet been accomplished. Research is still needed to determine cultivation techniques that will optimize productivity. As irrigation is considered to be the most important agronomic technique to enhance productivity, the goal of this investigation was to evaluate the effects of irrigation on leaf gas exchange (net photosynthesis rate and transpiration rate) and foliar and fruiting phenology. Our results suggest that irrigation acts by increasing the growth and fruit production of...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Hancornia speciosa; Neotropical savanna; Photosynthesis; Specific leaf area.
Ano: 2008
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202008000100001

Impacts of drought and temperature stress on coffee physiology and production: a review
Provedor de dados: 61
Autores: DaMatta,Fábio M.; Ramalho,José D. Cochicho.
Overall, drought and unfavourable temperatures are the major climatic limitations for coffee production. These limitations are expected to become increasingly important in several coffee growing regions due to the recognized changes in global climate, and also because coffee cultivation has spread towards marginal lands, where water shortage and unfavourable temperatures constitute major constraints to coffee yield. In this review, we examine the impacts of such limitations on the physiology, and consequently on the production of mainly Coffea arabica and C. canephora, which account for about 99 % of the world coffee bean production. The first section deals with climatic factors and the coffee plant’s requirements. The importance of controlling oxidative...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Coffea; Chilling; Frost; Heat; Photosynthesis; Water deficit; Water use; Yield.
Ano: 2006
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202006000100006

Influence of iron on mineral status of two rice (Oryza sativa L.) cultivars
Provedor de dados: 61
Autores: Silveira,Vivian C. da; Oliveira,Anna P. de; Sperotto,Raul A.; Espindola,Luciana S.; Amaral,Lívio; Dias,Johnny F.; Cunha,João B. da; Fett,Janette P.
Iron is an essential nutrient for plants. In aerobic conditions, Fe is highly unavailable for plant uptake, and Fe deficiency can be severe in plants grown in calcareous soils. In waterlogged soils, however, Fe availability increases and can reach toxic concentrations. Rice is an important staple crop worldwide and faces iron deficiency or excess, depending on the growth conditions. To contribute to the study of mechanisms involved in response to Fe deficiency and resistance to Fe excess, experiments were carried out with rice cultivars BR-IRGA 409 (I409, susceptible to Fe toxicity) and EPAGRI 108 (E108, resistant to Fe toxicity) grown in culture solutions and submitted to Fe excess, control concentration or deficiency (500, 6.5 or zero mg L-1 Fe,...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Ferritin; Iron deficiency; Iron toxicity; Mössbauer spectroscopy; Oryza sativa; PIXE.
Ano: 2007
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202007000200005

The lipid fraction of the coffee bean
Provedor de dados: 61
Autores: Speer,Karl; Kölling-Speer,Isabelle.
The lipid fraction of coffee is composed mainly of triacylglycerols, sterols and tocopherols, the typical components found in all common edible vegetable oils. Additionally, the so-called coffee oil contains diterpenes of the kaurene family in proportions of up to 20 % of the total lipids. Diterpenes are of interest because of their analytical and physiological effects. The composition of the main lipid components of the two most important coffee species, Coffea arabica and Coffea canphora var. Robusta is presented. In addition, the influences of typical processes like roasting and steaming on selected lipid components as well as the effects of the storage of green coffee beans under different conditions will be described. Furthermore, new findings...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Coffea; Coffee oil; Coffee wax; Diterpenes; 5-hydroxytryptamides.
Ano: 2006
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202006000100014

Use of physiological parameters as fast tools to screen for drought tolerance in sugarcane
Provedor de dados: 61
Autores: Silva,Marcelo de A.; Jifon,John L.; Silva,Jorge A.G. da; Sharma,Vivek.
Drought is one of the major limitations to plant productivity worldwide. Identifying suitable screening tools and quantifiable traits would facilitate the crop improvement process for drought tolerance. In the present study, we evaluated the ability of four relatively physiological parameters (variable-to-maximum chlorophyll a fluorescence ratio, F v/F m; estimated leaf chlorophyll content via SPAD index; leaf temperature, LT; and, leaf relative water content, RWC) to distinguish between drought tolerant and susceptible sugarcane genotypes subjected to a 90-d drought cycle. Eight field-grown genotypes were studied. By 45 d after the onset of treatments, the F v/F m, SPAD index and RWC of drought-stressed plants had declined significantly in all genotypes...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Chlorophyll a fluorescence; Relative water content; Leaf temperature; Saccharum; Water deficit.
Ano: 2007
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202007000300003

Myo-inositol content in pteridophytes and the isolation and characterization of L-myo-inositol-1-phosphate synthase from Diplopterygium glaucum
Provedor de dados: 61
Autores: Chhetri,D. R.; Mukherjee,A. K.; Adhikari,J.
Myo-inositol is involved in normal growth and development of all living organisms and L-myo-inositol-1-phosphate synthase (MIPS; EC: 5.5.1.4) is responsible for its de novo synthesis. This enzyme has been reported for a number of life forms including plants, animals and bacteria. In the present study free myo-inositol has been detected in the common pteridophytes found in the Darjeeling Himalayas and the enzyme, L-myo-inositol-1-phosphate synthase has been partially purified from Diplopterygium glaucum (Thunb.) Nakai. A crude homogenate from the reproductive pinnules of D. glaucum was subjected to streptomycin sulphate precipitation and 0-70% ammonium sulphate fractionation followed by successive chromatography through DEAE-cellulose, Hexylagarose and...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: D-glucose-6-phosphate; Gleicheniaceae; Inositol synthase; Myo-inositol.
Ano: 2006
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202006000200005

Flooding tolerance of tomato genotypes during vegetative and reproductive stages
Provedor de dados: 61
Autores: Ezin,Vincent; Pena,Robert De La; Ahanchede,Adam.
A greenhouse experiment was conducted to investigate the effect of flooding on two tomato cultivars and two wild related species. Forty days old tomato plants were subjected to a continuous flooding stress of different durations: 0, 2, 4 and 8 days. Plant pots were placed inside larger plastic pots; they were irrigated with excessive quantity of tap water at 25ºC so that the level of water above the surface of soil was 15 cm throughout the flooding period. At the bottom of each plastic pot a drilled hole allowed complete drainage of the pot after flooding. Parameters studied include plant height, number of leaves, leaf length, chlorophyll fluorescence, chlorophyll content, wilting, leaf senescence, adventitious root formation, number of flowers and fruits...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Tomato genotypes; Flooding conditions; Chlorophyll; Growth parameters; Yield and yield components.
Ano: 2010
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202010000200007

Leaf anatomy changes related to physiological adaptations to flooding in Amazonian tree species
Provedor de dados: 61
Autores: Herrera,Ana; Escala,Marcia; Rengifo,Elizabeth.
In trees of the seasonally flooded forest of the Mapire River in Venezuela, early flooding induces a reversible diminution in leaf conductance and photosynthetic rate. With the aim of finding an anatomical explanation for the observed responses of leaf gas exchange, the characteristics of emerged leaves developed under drainage or after three months of flooding were examined in the tree species Acosmium nitens, Campsiandra laurifolia, Duroia fusifera, Eschweilera tenuifolia, Pouteria orinocoensis and Symmeria paniculata and in leaves developed only under flooding in Inga spuria and Tachigali davidsei. Anatomy was remarkably similar among species and families and consisted of a bi-layered palisade parenchyma, a 5-6-cell-thick spongy parenchyma and large...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Flooding; Palisade; Parenchyma; Sclerenchyma; Spongy; Stomata; Tropical trees.
Ano: 2009
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202009000400006

Populational approach in ecophysiological studies: the case of Plathymenia reticulata, a tree from Cerrado and Atlantic Forest
Provedor de dados: 61
Autores: Lemos Filho,José Pires de; Goulart,Maíra Figueiredo; Lovato,Maria Bernadete.
The variability of ecophysiological traits among populations can be a result of selection in response to environmental pressure and/or due to random factors, like the genetic drift. The analysis of both genetic and phenotypic variation within populations can lead to better understanding of adaptation in order to colonize different habitats. In the last years we have developed several studies with an widely ecogeographic distributed legume tree species, Plathymenia reticulata, which were focused on identifying specific morphological and physiological traits related to adaptation to the habitats of origin of each studied population. We studied populations from Atlantic Forest, Cerrado and ecotonal sites in relation to phenology, seed morphological traits and...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Ecotypes; Evolutionary ecophysiology; Intraspecific variation; Local adaptation.
Ano: 2008
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202008000300005

Inoculation with mycorrhizal fungi modifies proline metabolism and increases chromium tolerance in pepper plants (Capsicum annuum L.)
Provedor de dados: 61
Autores: Ruscitti,Marcela; Arango,María; Ronco,Marta; Beltrano,José.
In general, heavy metals interfere with several physiological processes and reduce plant growth. Plants naturally establish symbiotic associations with soil microorganisms, such as mycorrhizal fungi. The aim of this research was to determine if inoculation with mycorrhizal fungi increases tolerance to Cr, evidenced by growth and biochemical parameters and the effect on roots membranes in Capsicum annum. Plants were either non-inoculated or inoculated with Glomus mosseae or Glomus intraradices, and grown in the presence of different concentration of Cr (K2Cr2O4) in soil. Pepper plants grown without Cr behaved as mycotrophic species. At the highest concentration (200 μM K2Cr2O4), Cr reduced root colonization by G. mosseae or G. intraradices (to 23 and 20%...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Electrolytes leakage; Glomus intraradices; Glomus mosseae; Heavy metals.
Ano: 2011
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202011000100004

Relationship between photochemical efficiency (JIP-Test Parameters) and portable chlorophyll meter readings in papaya plants
Provedor de dados: 61
Autores: Castro,Fernanda Assumpção; Campostrini,Eliemar; Torres Netto,Alena; Viana,Leandro Hespanhol.
The Portable Chlorophyll Meter (PCM) is used to estimate the total chlorophyll and leaf nitrogen content of various species. Since there is a relationship between the chlorophyll concentration and the photochemical efficiency, a relationship can also be established between the PCM readings and some fluorescence variables to provide information on photosystem II (PSII) structure and activity. Papaya (Carica papaya L.) plants ['Sunrise Solo' (leaves with intense green coloring) and 'Golden' cultivars (leaves with yellow-green coloring) were grown in a greenhouse with 30% interception of photosynthetically active photon flux density. The plants were cultivated in 15L plastics pots. Ninety to 100 days after planting the older leaves turned yellow and the...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Carica papaya; L. fluorescence JIP-Test Chlorophyll.
Ano: 2011
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202011000400007

Photosynthetic performance of Salvinia natans exposed to chromium and zinc rich wastewater
Provedor de dados: 61
Autores: Dhir,Bhupinder; Sharmila,P.; Saradhi,P. Pardha.
Investigations were carried out to evaluate alterations in photosynthetic performance of Salvinia natans (L.) exposed to chromium (Cr) and zinc (Zn) rich wastewater. Accumulation of high levels of Cr and Zn in plants affected photosynthetic electron transport. Photosystem- (PS) II-mediated electron transport was enhanced in plants exposed to Cr rich wastewater while a decline was observed in Zn-exposed plants. Photosystem-I-mediated electron transport increased in plants exposed to Cr and Zn rich wastewater. Efficiency of photosystem II (Fv/Fm) measured by fluorescence did not show any significant change in Cr-exposed plants but a decrease was observed in Zn-exposed plants as compared to the control. The enhancement in PS I-induced cyclic electron...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Carbon assimilation; Electron transport; Heavy metals; Photophosphorylation; Redox status.
Ano: 2008
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202008000100007

Morpho-physiological responses of cowpea leaves to salt stress
Provedor de dados: 61
Autores: Lacerda,Claudivan F.; Assis Júnior,José O.; Lemos Filho,Luiz C. A.; Oliveira,Teógenes S. de; Guimarães,Francisco V.A.; Gomes-Filho,Enéas; Prisco,José T.; Bezerra,Marlos A.
The effect of salt stress of known intensity and duration on morpho-physiological changes in leaves of different ages from cowpea [Vigna unguiculata (L.) Walp.] plants was studied, aiming for a better understanding of the acclimation process of the whole-plant. Seeds were sown in vermiculite and seedlings were transferred to plastic trays containing aerated nutrient solution, and kept in a greenhouse. When the first trifoliate leaf emerged the seedlings were transplanted into 3 L plastic pots containing aerated nutrient solution. Salt additions started 5 d later, and the salt-treated plants received 25 mmol L-1 per day until reaching a final concentration of 75 mmol L-1. During the experimental period primary leaves and the 1st, 2nd, and 3rd trifoliate...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Ion concentration; Photosynthate partitioning; Photosynthesis; Salinity; Stress acclimation.
Ano: 2006
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202006000400003

Seasonal variation in the maximum rate of leaf gas exchange of canopy and understory tree species in an Amazonian semi-deciduous forest
Provedor de dados: 61
Autores: Sendall,Kerrie M.; Vourlitis,George L.; Lobo,Francisco A.
Leaf gas exchange, water potential, and specific leaf area of two tropical semi-deciduous tree species, Brosimum lactescens S. Moore and Tovomita schomburgkii Planch &amp;amp; Triana, were quantified to establish how these properties were affected by seasonal variations in rainfall and leaf canopy position. The study was conducted at a site near Sinop Mato Grosso, Brazil, which is located within the ecotone of savanna and tropical rain forest. Both species exhibited significant declines in leaf water potential (ΨL), specific leaf area, area- and mass-based light saturated photosynthesis and dark respiration, and maximum stomatal conductance during the dry-season, suggesting that leaf structural properties and gas exchange are significantly altered by...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Brazil; Brosimum lactescens; Climate change; Ecotone; Photosynthetic response; Tovomita schomburgkii; Tropical transitional forest.
Ano: 2009
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202009000100008

Coffee biotechnology
Provedor de dados: 61
Autores: De Los Santos-Briones,César; Hernández-Sotomayor,S. M. Teresa.
In the last three decades, interest has turned to in vitro cell culture in different areas of coffee research. In vitro techniques have been applied not only for coffee improvement through genetic transformation but also to study various aspects in coffee cells such as chemical (caffeine synthesis and the production of coffee aroma), physiological and more recently, biochemical aspects. The most important advances obtained to date on in vitro coffee techniques in fields like biochemistry, physiology, regeneration systems and genetic engineering, are presented and discussed.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Coffea; Coffee; Genetic transformation; In vitro tissue culture; Regeneration; Somatic embryogenesis.
Ano: 2006
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202006000100015

Leaf optical properties as affected by shade in saplings of six tropical tree species differing in successional status
Provedor de dados: 61
Autores: Souza,Rogéria Pereira; Válio,Ivany F. M.
Tree species differing in successional status may present different responses to shade. Adjustments at leaf level may affect their optical properties, leading to changes in PAR (photosynthetically active radiation) absorbance. The aim of this study was to evaluate leaf optical properties as affected by understory shade in saplings of six tropical tree species differing in successional status and degree of shade tolerance. Chlorophyll content and specific leaf area (SLA) were also evaluated. The effects of shade on leaf optical properties and chlorophyll content differed among the studied species, whereas increased SLA was a common response for all species, reflecting the occurrence of thinner leaves under shade. The three studied shade-tolerant species -...
Tipo: Info:eu-repo/semantics/other
Palavras-chave: Chlorophyll; Leaf absorbance; Shade tolerance; Specific leaf area; Successional species.
Ano: 2003
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202003000100007

The master and the pupil: two close friends, two great plant physiologists
Provedor de dados: 61
Autores: Barros,Raimundo Santos.
Tipo: Info:eu-repo/semantics/other
Ano: 2011
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202011000100002

Editorial
Provedor de dados: 61
Autores: DaMatta,Fábio M.
Tipo: Info:eu-repo/semantics/other
Ano: 2006
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202006000300001

Resprouting ability and intensity after damage in seedlings of the large-seeded species Araucaria angustifolia
Provedor de dados: 61
Autores: Alabarce,Fernanda da Silva; Dillenburg,Lucia Rebello.
The role of seed reserves on the ability to resprout and on the responses of resprouting in Araucaria angustifoliawas investigated. Seedlings were separated into three groups: plants which had their shoot damaged, a similar group in which damaged plants had their connection to the supporting seed removed, and a control group. All damaged seedlings resprouted, but those which remained connected to their seeds had a greater mass of resprouted shoots than the ones disconnected from their seeds. A greater accumulation of seed mass in the underground hypocotyl was a very distinct initial response to damage, but, on the long run, damaged plants were able to reestablish a biomass allocation pattern, which was very similar to the control plants. These results...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Brazilian pine; Herbivory; Resource allocation; Seed size; Storage.
Ano: 2012
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202012000200006

Growth, photosynthesis and stress indicators in young rosewood plants (Aniba rosaeodora Ducke) under different light intensities
Provedor de dados: 61
Autores: Gonçalves,José Francisco de Carvalho; Barreto,Denize Caranhas de Sousa; Santos Junior,Ulysses Moreira dos; Fernandes,Andreia Varmes; Sampaio,Paulo de Tarso Barbosa; Buckeridge,Marcos Silveira.
Aniba rosaeodora is an Amazonian tree species that belongs to the family Lauraceae. Due to intense exploitation for extraction of essential oils (mainly linalol), A. rosaeodora is now considered an endangered species. On the other hand, there is little information about its ecophysiology which would be useful to support future forest planting programs. Hence, the effect of different light intensities on the growth and photosynthetic characteristics of young plants of A. rosaeodora was studied. Nine-month-old plants were subjected to four light treatments (T1= 10 a 250 µmol.m-2.s-1 / control; T2=500 to 800, T3=700 to 1000 and T4=1300 to 1800 µmol.m-2.s-1 / full sunlight). Allometric variables, gas exchange, contents of pigments and chlorophyll a...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Chlorophyll a fluorescence; Chloroplast pigment contents; Gas exchanges; Photochemical efficiency of photosystem II; Relative growth rate; Tropical species.
Ano: 2005
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202005000300007

Effects of the size of sown seed on growth and yield of common bean cultivars of different seed sizes
Provedor de dados: 61
Autores: Lima,Elvis Rodrigues; Santiago,Aline Silva; Araújo,Adelson Paulo; Teixeira,Marcelo Grandi.
A field experiment was conducted to evaluate the effects of planting different sizes of seed of the same cultivar on biomass accumulation and grain yield of common bean (Phaseolus vulgaris L.) cultivars of different seed sizes. A 6 X 2 split-plot factorial design with four replicates was employed, with six bean cultivars as main plots and two seed sizes (small and large, the latter twice as heavy as the former) of the same cultivar as subplots. Eight weekly samplings of biomass were performed, and yield components were measured at maturity. Large seeds increased the leaf area index and the shoot and root biomass of bean cultivars, particularly at the beginning of the growth cycle, but they did not affect the pod biomass. Improved growth associated with the...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Phaseolus vulgaris; Genotype; Growth analysis; Leaf area; Yield components.
Ano: 2005
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202005000300001

Oleoresin yield of Pinus elliottii Engelm seedlings
Provedor de dados: 61
Autores: Ferreira,Alfredo Gui; Fior,Claudimar Sidnei; Gualtieri,Sonia Cristina Juliano.
Pinus elliottii is a fast-growing conifer well adapted to southern Brazil, used for wood fiber and resin production. Oleoresin production is part of the plant's defense systems and is induced by ethylene, which production is stimulated by hypoxic conditions. The experiment was designed with the goal of verifying whether one year-old plants had measurable oleoresin yield and if flooding led to increased oleoresin production. There was an increase of 78% in oleoresin production after 14 to 21 days of flooding and plants with larger stem diameters were more productive.
Tipo: Info:eu-repo/semantics/other
Palavras-chave: Flooding; Defense mechanisms slash pine.
Ano: 2011
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202011000400009

Variations in sugars and cyclitols during development and maturation of seeds of brazilwood (Caesalpinia echinata Lam., Leguminosae)
Provedor de dados: 61
Autores: Borges,Igor F.; Barbedo,Claudio J.; Richter,Andreas A.; Figueiredo-Ribeiro,Rita de Cássia L.
Seeds of Caesalpinia echinata are tolerant to desiccation, keeping their viability up to 0.08 g H2O g-1 DM. When stored under laboratory conditions they lose their viability within one month, while under low temperatures germination ability is maintained during two years of storage. Here, we report on the variations of soluble carbohydrates, cyclitols and cyclitol galactosides in seeds of C. echinata during development and maturation, aiming for a better understanding of the involvement of these compounds in the maturation process and seed quality. Individual flowers were tagged on the day of anthesis and pods were collected directly from the branches from 32 to 59 d after anthesis (DAA). Seeds were also collected after shedding. The physiological maturity...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Seed development; Seed viability; Soluble carbohydrates.
Ano: 2006
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202006000400005

Atividade fotossintética e peroxidação de lipídios de membrana em plantas de aroeira-do-sertão sob estresse hídrico e após reidratação
Provedor de dados: 61
Autores: Queiroz,Cristina G. S.; Garcia,Queila S.; Lemos Filho,José Pires.
Avaliaram-se os efeitos do estresse hídrico e da reidratação sobre parâmetros de fluorescência, condutância estomática e peroxidação de lipídios em plantas de Myracrodruon urundeuva Fr. All. (Anacardiaceae). As plantas foram cultivadas em casa de vegetação e a seca foi induzida por suspensão da irrigação durante 14 dias. Sob estresse hídrico, observou-se queda acentuada no conteúdo relativo de água foliar, o qual alcançou valores próximos a 60 %. Essa queda foi acompanhada por grande diminuição na condutância estomática e na taxa aparente de transporte de elétrons (ETR) e extensivos danos às membranas evidenciados por aumentos na peroxidação de lipídios. Apesar do decréscimo nos valores de ETR, não se observaram alterações nos valores do rendimento...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Condutância estomática; Estresse oxidativo; Fluorescência; Fotossíntese; Myracrodruon urundeuva.
Ano: 2002
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202002000100008

Effects of n-propyl gallate on photosynthesis and physiological parameters in Dunaliella salina are affected by stressful conditions
Provedor de dados: 61
Autores: Einali,Alireza; Shariati,Mansour.
We studied the effects of n-propyl gallate, which is a plastid terminal oxidase inhibitor involved in chlororespiration, on photosynthesis and physiological parameters in Dunaliella salina grown under different salinities and under low or high irradiance using chlorophyll a fluorescence transient measurements and pigment analysis. The inhibitor up to 1 mM had an additive significant effect on the photosynthetic efficiency in the cell suspensions grown under low salinity and irradiance. However, in the presence of high n-propyl gallate concentration (4 mM), there was a negative effect on all physiological aspects. In contrast, this high concentration of the inhibitor could enhance efficiency of electron transport and growth parameters under high irradiance....
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Chlorophyll fluorescence; Dunaliella salina; Light intensity; Photosynthesis; Salt stress.
Ano: 2012
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202012000300006

Growth, photosynthesis and leaf water potential in young plants of Copaifera langsdorffii Desf. (Caesalpiniaceae) under contrasting irradiances
Provedor de dados: 61
Autores: Ronquim,Carlos Cesar; Prado,Carlos Henrique B. A.; Souza,João Paulo de.
Growth and leaf nutrient content were compared in young potted plants of Copaifera langsdorffii in sunny and shaded areas without water stress. Besides, carbon assimilation and leaf water relations were evaluated by net photosynthesis, potential photochemical efficiency and leaf water potential during daily courses in dry and rainy periods under natural conditions in both contrasting irradiances. Higher values of total biomass, height and leaf area occurred in sunny than in shaded area. On the other hand, all young plants survived in shade under natural water stress probably by reason of fast and intense biomass accumulation in favor of roots in early development. There was no significant difference about nutrient concentration in leaves between plants...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Cerrado; Biomass partitioning; Chlorophyll fluorescence; Leaf gas exchange; Irradiance; Sunflecks.
Ano: 2009
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202009000300004

Induced response against herbivory by chemical information transfer between plants
Provedor de dados: 61
Autores: Campos,Wellington G.; Faria,Ana P.; Oliveira,Maria Goreti A.; Santos,Hérica L.
Plants respond to herbivores and pathogens attack with increased emission of volatile organic compounds. These molecules act as indirect defences when attracting natural enemies of herbivores and thus benefit the plant. It remains controversial whether undamaged plants capture chemicals released by damaged neighbouring plants and respond to them by increasing their defensive barriers against an imminent attack. In spite of public appeal and of this being the 25th year of the Talking Trees Hypothesis, only recently have the most sceptical scientists been convinced. The induced response to herbivory by interplant information transfer has been found in two plant-herbivore systems. However, the universality of the phenomenon and its ecological and evolutionary...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Induced resistance; Induced defense; Insect-plant interaction; Interplant air signalling; Interplant communication; Talking tress.
Ano: 2008
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202008000400001

Improving the management and mobility of BJPP
Provedor de dados: 61
Autores: Bressan-Smith,Ricardo.
Tipo: Info:eu-repo/semantics/other
Ano: 2012
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202012000300001

Effects of flooding and shading on growth and gas exchange of Vochysia divergens Pohl (Vochysiaceae) of invasive species in the Brazilian Pantanal
Provedor de dados: 61
Autores: Dalmolin,Ândrea Carla; Dalmagro,Higo José; Lobo,Francisco de Almeida; Antunes Junior,Mario Zortéa; Ortíz,Carmen Eugenia Rogríguez; Vourlitis,George Louis.
Vochysia divergens Pohl (commonly known as cambara) is a pioneer tree species that is native to the Amazon Basin but has been invading the seasonally flooded wetlands of the Brazilian Pantanal, forming monospecific communities. The physiological aspects associated with cambara invasion, including the effects of flooding and shading on growth and leaf gas exchange, are unknown but may shed light on why cambara is able to invade this novel habitat so rapidly. Thus, we conducted a manipulative experiment to quantify the effects of shading and flooding on the growth, gas exchange and leaf nutrient content of V. divergens saplings. Based on previous research we hypothesized that (1) experimental flooding would have no effect on the growth and gas exchange of V....
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Cambara; Physiological stress; Photosynthesis; Plant ecophysiology; Stomatal conductance; Tropical wetlands.
Ano: 2012
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202012000200001

Influence of shoot inclination on irradiance and morphophysiological leaf traits along shoots in cerrado trees with distinct leaf deciduousness
Provedor de dados: 61
Autores: Souza,João Paulo; Prado,Carlos Henrique B. A.; Damascos,Maria A.; Albino,Ana Lúcia S.
This study investigated the relationship among shoot inclination, irradiance and morphophysiological traits of basal (BL) and distal (DL) leaves in six cerrado trees with distinct leaf deciduousness. Deciduous species showed plagiotropic shoots (44º) and larger leaf area than semideciduous and evergreen species, which showed orthotropic shoots (56º and 63º, respectively). Despite larger leaf area, irradiance at shoot base in deciduous was around 85% in relation to full irradiance, while in semideciduous and evergreen only 23% of irradiance reached on BL. Likewise, maximum net photosynthesis (Pnmax) was similar between BL and DL in deciduous. Contrastingly, semideciduous and evergreen showed significant decreasing of Pnmax in BL. Plagiotropic shoots of...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Leaf-life-span; Maximum net photosynthesis; Orthotropic; Self-shading; Plagiotropic.
Ano: 2009
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202009000400004

Physiology of cashew plants grown under adverse conditions
Provedor de dados: 61
Autores: Bezerra,Marlos A.; Lacerda,Claudivan F. de; Gomes Filho,Enéas; Abreu,Carlos E. B. de; Prisco,José T.
The cashew (Anacardium occidentale L.) is an important crop for semi-arid agriculture and contributes to the social and economical development of several world regions, including the northeast of Brazil. In spite of its importance, very few studies aim to understand the effects of abiotic stresses on the development and yield of the cashew. This review covers the research on cashew ecophysiology, with emphasis on the effects of water and salt stress on its development, mineral nutrition and gas exchange processes. The results presented here were obtained at different plant growth stages and under different environmental conditions of soil and climate. The ecophysiological significance of this information is also discussed.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Anacardium occidentale; Development; Salt stress; Water deficit.
Ano: 2007
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202007000400012

Identification of methyl jasmonate-responsive genes in sugarcane using cDNA arrays
Provedor de dados: 61
Autores: De Rosa Jr.,Vicente E.; Nogueira,Fábio T. S.; Menossi,Marcelo; Ulian,Eugênio C.; Arruda,Paulo.
Jasmonic acid (JA) and its ester methyl jasmonate (MeJA) are linolenic acid-derived signaling molecules involved in plant development and stress responses. MeJA regulates gene expression at transcription, RNA processing and translation. We investigated the changes in gene expression in sugarcane leaves exposed to MeJA using cDNA arrays. Total RNA isolated at 0, 0.5, 1, 3, 6, and 12 h following MeJA treatment was labeled with alpha-33P-dCTP and hybridized to nylon filters containing 1,536 cDNA clones. A significant increase in gene expression in response to MeJA was detected for both novel and well known stress-related genes, while genes participating in photosynthesis and carbohydrate assimilation were down-regulated. Searches for conserved domains in...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: CDNA array; Expression profiling; Methyl-jasmonate; Signaling molecules; Sugarcane.
Ano: 2005
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202005000100014

Change in root apical protein and peroxidase activity in response to aluminum in tolerant and sensitive maize inbred lines
Provedor de dados: 61
Autores: Souza,Isabel Regina Prazeres de; Alves,Vera Maria Carvalho; Parentoni,Sidney Netto; Oliveira,Antônio Carlos de; Teixeira,Flávia França; MacAdam,Jennifer Wilson; Purcino,Antônio Álvaro Corsetii.
The effects of a short-term (80 min) exposure to 222 µM aluminum (Al) on the protein content and expression and on peroxidase activity and isoenzymes in the primary root of maize were evaluated. Two inbred lines differing in their level of tolerance to Al were used: Cateto 237 (tolerant) and L36 (sensitive). The apical 20 mm of the primary root was divided into 2-mm-long segments that were analyzed for total protein content and peroxidase activity. These results demonstrate that the total protein content along the root apex was not affected by Al in the tolerant inbred line, but decreased in the sensitive line. In the apical 2 mm of the root of the sensitive line, the expression of low molecular weight proteins (43 kDa or smaller) was decreased. Expression...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Aluminum toxicity; Maize; Peroxidase isoforms; Root growth.
Ano: 2002
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202002000300006

Purification and molecular mass determination of a lipid transfer protein exuded from Vigna unguiculata seeds
Provedor de dados: 61
Autores: Diz,Mariângela S. S.; Carvalho,André O.; Gomes,Valdirene M.
Plants exude a variety of substances through their surface especially of roots and germinating seeds. Some of these released compounds seem to have an inhibitory action against certain pathogens. Lipid transfer proteins (LTPs) are 9 kDa cysteine-rich cationic peptides and are thought to play a role in the protection of plants against microbial infections. The aim of this work was to isolate and determine the molecular mass of a LTP present in the exudates of imbibed cowpea seeds. For exudation induction, 50 seeds were submerged in 50 mL sterile 100 mmol.L-1 Na-acetate buffer, pH 4.5 and shaken at 30 ºC for 24 h. The resulting exudate was subjected to ammonium sulphate fractionation and the pellet formed between 0 and 70 % saturation was dialysed and...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Defense proteins; LTP; Seed exudates.
Ano: 2003
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202003000300007

Transpiration, leaf diffusive conductance, and atmospheric water demand relationship in an irrigated acid lime orchard
Provedor de dados: 61
Autores: Angelocci,Luiz Roberto; Marin,Fábio Ricardo; Oliveira,Ricardo Ferraz de; Righi,Evandro Zanini.
Leaf vapor diffusive conductance (gl) and transpiration (T) measurements in an irrigated orchard of the acid lime "Tahiti" were carried out in a subtropical climatic condition in the State of São Paulo, Brazil. Measurements were made using steady-state null-balance porometers and were taken throughout the day, on several occasions from February to November, 1998. During September and October, measurements were performed on exposed and shaded young and fully expanded leaves, as well as on old leaves inside the tree canopy. The old leaves showed lower values of gl and T when compared to the other groups. In the other months, measurements were taken only with exposed and shaded fully expanded leaves. The highest values of gl and T were obtained from February...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Air temperature; Photosynthetic photon flux density; Porometry; Stomata; Vapor pressure deficit.
Ano: 2004
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202004000100008

Latex fluids are endowed with insect repellent activity not specifically related to their proteins or volatile substances
Provedor de dados: 61
Autores: Ramos,Márcio V.; Araújo,Eliane S.; Oliveira,Raquel S. B.; Teixeira,Fabiano M.; Pereira,Danielle A.; Cavalheiro,Mariana G.; Souza,Diego P.; Oliveira,Jefferson S.; Freitas,Cleverson D. T. de.
Latex is an endogenous milky fluid synthesized and accumulated under pressure in a network of laticifer cells. In this study, latices from five plant species were examined for deterrent effect on oviposition of two Coleoptera (Bruchidae) pests. The latex from Euphorbia tirucalli, Calotropis procera and Plumeria rubrae exhibited deterrent activity on oviposition of both Callosobruchus maculatusand Zabrotis subfasciatus beetles. The latex from Cryptostegia grandiflora and Himathantus drasticus were less effective to C. maculatus and Z. subfasciatus oviposition, respectively. Eggs laid on latex-treated seeds were not affected.The emergence and the mean time of development and weight of larvae grown in treated seeds were similar to the controls. The deterrent...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Calotropis procera; Deterrent activity; Insect; Laticifers; Proteins; Plumeria rubra.
Ano: 2011
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202011000100008

Study of the effect of Aliette on the activity of spinach (Spinacea oleracea L.) chloroplasts
Provedor de dados: 61
Autores: Almeida,Pedro; Coutinho,João P.; Rocha,João; Gomes-Laranjo,José.
Intensification of production in modern agriculture is frequently obtained thanks to the increase of pesticide applications and chemical fertilizers. However, the use of these products sometimes causes a reduction of crop productivity. We aimed to evaluate the impact of the fungicide Aliette on in vitro activity of chloroplasts of spinach (Spinacea oleracea L.). Transmembrane potential formation, PSII oxygen evolution and PSII photochemistry were analyzed. Our results showed that the recommended concentration (2.5 g L-1) of Aliette did not impair the photosynthetic apparatus. However, at higher concentrations (&gt; 7.5 g L-1), reductions in thylakoid membrane potential and oxygen evolution were recorded, but with no evidence of photoinhibition.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Bioenergetics; Ecotoxicology; Pesticides; Photosynthesis; Xenobiotics.
Ano: 2007
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202007000100009

Coffee seed physiology
Provedor de dados: 61
Autores: Eira,Mirian T. S.; Silva,E. A. Amaral da; De Castro,Renato D.; Dussert,Stéphane; Walters,Christina; Bewley,J. Derek; Hilhorst,Henk W. M.
Considerable advances in our understanding of coffee seed physiology have been made in recent years. However, despite intense research efforts, there are many aspects that remain unclear. This paper gives an overview of the current understanding of the more important features concerning coffee seed physiology, and provides information on recent findings on seed development, germination, storage and longevity.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Coffea; Coffee; Germination; Germplasm; Longevity; Seed development; Storage.
Ano: 2006
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202006000100011

Changes in nitrate reductase activity and oxidative stress response in the moss Polytrichum commune subjected to chromium, copper and zinc phytotoxicity
Provedor de dados: 61
Autores: Panda,Sanjib Kumar; Choudhury,Shuvasish.
The main aim of this paper was to investigate the effect of chromium (Cr), copper (Cu) and zinc (Zn) on nitrate reductase (NR) activity and oxidative stress responses in the moss Polytrichum commune. Cr, Cu and Zn resulted in the inhibition of NR activity. A decline in total chlorophyll content was observed after 24 and 48 h of metal treatment. Accumulation of the metals showed a dose and time dependent increase. High accumulation of Cu, Cr and Zn were seen in moss shoots after 24 and 48 h of treatment. Treatment of Cr, Cu and Zn for 24 or 48 h resulted in the increase of malondialdehyde (MDA) content in moss shoots. The highest increase was observed in shoots under Cu treatment followed by Cr and Zn. The MDA content was significantly higher after 48h....
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Antioxidants; Chromium; Copper; Malondialdehyde; Nitrate reductase; Oxidative stress; Polytrichum commune; Zinc.
Ano: 2005
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202005000200001

Molecular cloning of a full-length cDNA and gene from Coffea arabica encoding a protein homologous to the yeast translation initiation factor SUI1: expression analysis in plant organs
Provedor de dados: 61
Autores: Gaborit,Charlotte; Caillet,Victoria; Deshayes,Alain; Marraccini,Pierre.
A full-length cDNA (CaSUI1) was isolated from a Coffea arabica cDNA library from beans during maturation. Its putative translational product is highly homologous to the SUI1 protein of Saccharomyces cerevisiae which functions in concert with eIF2 and the initiator tRNA-Methionin in directing the ribosome to the proper start site of translation. The corresponding gene from coffee was also cloned and sequenced. Its organization is very similar to what observed for the same gene from rice (Oryza sativa) particularly regarding the position and length of its introns. The expression of CaSUI1 gene was also checked and showed that it was highly expressed in all coffee tissues analyzed, therefore confirming the essential role of the SUI1 protein in cell...
Tipo: Info:eu-repo/semantics/other
Palavras-chave: Coffea arabica; Constitutive gene expression; GOS2; SUI1; Translational initiation.
Ano: 2003
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202003000100008

Pollen treatment in high osmotic potential: a simple tool for in vitro preservation and manipulation of viability in gametophytic populations
Provedor de dados: 61
Autores: Loguercio,Leandro Lopes.
A method for in vitro preservation and manipulation of pollen viability based on simple changes in osmotic potential (sucrose concentrations) in culture media was developed using tobacco pollen as the experimental model. High osmotic potentials were capable of reversibly inhibiting pollen germination, preserving its viability at room temperature for long periods, as assessed by subsequent incubation in germination medium. When pollen was pre-germinated for different periods and subsequently incubated in 80 % sucrose medium (inhibiting medium) there was a progressive decrease in its viability, which was a trend best described by a quadratic regression line. Nevertheless, very small variations in pollen-tube lengths and viable pollen grains more resistant to...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Gametophytic selection; In vitro pollen germination; Nicotiana tabacum; Pollen storage; Pollen viability.
Ano: 2002
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202002000100009

Activation of phospholipase PLA2 actvity in Ricinus communis leaves in response to mechanical wounding
Provedor de dados: 61
Autores: Domingues,Sarah J.S.; Souza,Thiago F. de; Soares,Alexandra M.S.; Jacinto,Tânia; Machado,Olga L.T.
In order to investigate the defense response in castor bean (Ricinus communis) against predators, we analyzed the effect of mechanical wounding upon the phospholipase A2 (PLA2) activity of leaf extracts. Time course experiments revealed that the highest levels of increased PLA2 activity (ca. two fold) occurred 15 min and 60 min after injury. The induced activities demonstrated high sensitivity towards aristolochic acid (10 mM), a PLA2 inhibitor. Based on SDS-PAGE analysis, the PLA2 activity induced 15 min after wounding migrated with a molecular mass of 40 kDa and was denoted RcPLA2 I. The protein activity induced 60 min after wounding, RcPLA2 II, migrated with a molecular weight of 14 kDa. Furthermore its N-terminal sequence shared homology with PLA2 from...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Cellular defense; Castor bean; Plant signaling; Phospholipase A2; Ricinus communis.
Ano: 2007
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202007000100004

Positive, negative and marker-free strategies for transgenic plant selection
Provedor de dados: 61
Autores: Aragão,Francisco José Lima; Brasileiro,Ana Cristina Miranda.
In this review, the use of the most common selection marker genes on plant transformation and the effects of their respective selective agents are discussed. These genes could be divided in two categories according their mode of action: genes for positive and negative selection. The retention of the marker gene flow through chloroplast transformation is also discussed. Further, strategies to recover marker-free transgenic plants, involving multi-auto-transformation (MAT), co-transformation, site-specific recombination and intragenomic relocation of transgenes through transposable elements are reviewed.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Antibiotic resistance; Herbicide resistance; Marker genes; Plant transformation; Selection; Transgenic plant.
Ano: 2002
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202002000100001

Metabolic activity of fresh-cut 'Pérola' pineapple as affected by cut shape and temperature
Provedor de dados: 61
Autores: Antoniolli,Lucimara R.; Benedetti,Benedito C.; Sigrist,José M.M.; Souza Filho,Men de Sá M.; Alves,Ricardo E.
The effects of cut shape and temperature on the respiratory activity and ethylene synthesis of fresh-cut 'Pérola' pineapple were investigated. Two experiments were carried out. In the first, slices and chunks were placed in air-tight packages kept at 4 or 10ºC. Gas samples were taken every 2 h during 12 h and analysed by gas chromatography. In the second experiment, peeled fruits, slices and chunks were placed in air-tight glass jars connected to a flowboard installed in a cold room at 5 ± 1ºC. This system provided a continuous flow of humid and cold air during 14 d. Respiration rate was determined every 2 h, during the first 12 h, then daily for 10 d and on days 12 and 14. Ethylene synthesis was not detected during 12 h of evaluation. The lower...
Tipo: Info:eu-repo/semantics/other
Palavras-chave: Ananas comosus; Ethylene; Minimal processing; Respiration rate.
Ano: 2006
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202006000300008

Induction of chalcone synthase and phenylalanine ammonia-lyase by salicylic acid and Colletotrichum lindemuthianum in common bean
Provedor de dados: 61
Autores: Campos,Ângela Diniz; Ferreira,Alfredo Gui; Hampe,Magdolna Maria Vozári; Antunes,Irajá Ferreira; Brancão,Nely; Silveira,Expedito P.; Silva,João Batista da; Osório,Vera Algayer.
The activities of the enzymes chalcone synthase (CHS) and phenylalanine ammonia-lyase (PAL) were measured in leaf extracts obtained from four cultivars of the common bean (AB 136, Rio Tibagi, Carioca and Macanudo). Two stages of plant development were examined: plantlets (V2) and the onset of blooming (R6). Initially, the plants were either treated with salicylic acid or inoculated with the delta race of Colletotrichum lindemuthianum (inductive fungus) and after three days they were evaluated for enzyme activity. Afterwards, all plants were inoculated (challenged) with the virulent pathotype 33/95 of C. lindemuthianum except for the water control. Five days later, the activities of PAL and CHS were evaluated. There were significant changes in the...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Anthracnose; Phaseolus vulgaris; Systemic acquired resistance.
Ano: 2003
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202003000300001

Response of Cucumis sativus L. seedlings to Pb exposure
Provedor de dados: 61
Autores: Gonçalves,Jamile F.; Becker,Alexssandro G.; Pereira,Luciane B.; Rocha,João B. T. da; Cargnelutti,Denise; Tabaldi,Luciane A.; Battisti,Vanessa; Farias,Júlia G.; Fiorenza,Amanda M.; Flores,Érico M. M.; Nicoloso,Fernando T.; Schetinger,Maria R. C.
In this study, the effects of lead (Pb) on growth, photosynthetic pigments concentration, lipid peroxidation, electrolyte leakage percentage (ELP), protein oxidation, aminolevulinate dehydratase (ALA-D; E.C. 4.2.1.24), ascorbate peroxidase (APX; E.C. 1.11.1.11), catalase (CAT; E.C. 1.11.1.6) and superoxide dismutase (SOD; E.C. 1.15.1.1) activities, and ascorbic acid (AsA), non-protein thiol groups (NPSH) and total soluble protein concentrations in cucumber seedlings (Cucumis sativus L.) were investigated. Seedlings were grown in vitro in an agar-solidified substrate containing three Pb levels as (C2H3O2)Pb.3H2O (0, 100, 400, and 1000 µmol L-1) for 10 d. Increasing Pb concentrations in substrate enhanced Pb concentration in both roots and shoot. Pb...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Antioxidant enzymes; Cucumber; Lipid peroxidation; Pb; Photosynthetic pigments; Protein oxidation.
Ano: 2009
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202009000300002

Chromium stress in plants
Provedor de dados: 61
Autores: Panda,S.K.; Choudhury,S.
The article presents an overview of the mechanism of chromium stress in plants. Chromium is known to be a toxic metal that can cause severe damage to plants and animals. Chromium-induced oxidative stress involves induction of lipid peroxidation in plants that causes severe damage to cell membranes. Oxidative stress induced by chromium initiates the degradation of photosynthetic pigments causing decline in growth. High chromium concentration can disturb the chloroplast ultrastructure thereby disturbing the photosynthetic process. Like copper and iron, chromium is also a redox metal and its redox behaviour exceeds that of other metals like Co, Fe, Zn, Ni, etc. The redox behaviour can thus be attributed to the direct involvement of chromium in inducing...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Antioxidants; Chromium; Fenton reactions; Metallothioneins; Oxidative stress.
Ano: 2005
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202005000100008

Inter-specific variability in protein use by two vegetable crop species
Provedor de dados: 61
Autores: Adamczyk,Bartosz; Godlewski,Mirosław.
It is now well-known that plants can uptake not only inorganic nitrogen but also organic nitrogen compounds, mainly amino acids. However, soil proteins are the main pool of amino acids. According to our earlier papers, plants can get access to this source of nitrogen using root-secreted proteases, but the level of proteolytic activity of such root-secreted proteases is species-specific. Our aim was to compare the use of protein as nitrogen source by two vegetable crops having high (Allium porrum) or low (Lactuca sativa) level of activity of root-secreted proteases. Seedlings were cultivated on Murashige and Skoog medium (MS), MS medium without inorganic nitrogen, MS medium without inorganic nitrogen, but with casein in concentration of 0.01%, 0.1% or 1%....
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Organic nitrogen; Plant nitrogen nutrition; Secretion of proteases.
Ano: 2010
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202010000300004

Physiological responses of NaCl stressed cowpea plants grown in nutrient solution supplemented with CaCl2
Provedor de dados: 61
Autores: Silva,José Vieira; Lacerda,Claudivan Feitosa de; Costa,Paulo Henrique Alves da; Enéas Filho,Joaquim; Gomes Filho,Enéas; Prisco,José Tarquínio.
Pitiuba cowpea (Vigna unguiculata (L.) Walp.) plants were grown in nutrient solution and kept in a greenhouse up to pre-flowering stage. They were subjected to four different treatments: nutrient solution; nutrient solution containing 75 mmol.L-1 NaCl; nutrient solution containing 75 mmol.L-1 NaCl and 5 mmol.L-1 CaCl2; and nutrient solution containing 75 mmol.L-1 NaCl and 10 mmol.L-1 CaCl2. Salt stress strongly inhibited plant growth, caused a disturbance in plant-water balance, and increased the total content of inorganic solutes in the different plant parts, due mainly to accumulation of Na+ and Cl-. It also increased leaf and root soluble carbohydrates, reduced soluble amino nitrogen both in root tips and in the youngest trifoliate leaves, and reduced...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Calcium; Growth; Salt stress; Solutes accumulation; Vigna unguiculata; Water relations.
Ano: 2003
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202003000200005

Cadmium-induced oxidative stress and antioxidative enzyme response in water hyacinth and salvinia
Provedor de dados: 61
Autores: Vestena,Silvane; Cambraia,Jose; Ribeiro,Cleberson; Oliveira,Juraci A.; Oliva,Marco A.
The reactive oxygen species generation, lipid peroxidation and antioxidative enzyme response of water hyacinth and salvinia to Cd were evaluated. Cadmium was absorbed/accumulated mainly in the roots, but significant amounts also translocated to the leaves. No Cd effect on dry weight was detected, although toxicity symptoms were visible. Superoxide and H2O2 concentrations increased, in addition to lipid peroxidation in both species, especially in the leaves of salvinia. In general, antioxidative enzyme activities were reduced in both species following Cd treatment, especially in salvinia. Glutathione peroxidase (GPX, EC 1.11.1.9) activity decreased in water hyacinth but increased in salvinia. Glutathione S-transferase (GST, EC 2.5.1.18) activity increased...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Aquatic plants; Eichhornia crassipes; Metal toxicity; Oxidative stress; Salvinia auriculata.
Ano: 2011
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202011000200005

Metabolism of alkaloids in coffee plants
Provedor de dados: 61
Autores: Ashihara,Hiroshi.
Coffee beans contain two types of alkaloids, caffeine and trigonelline, as major components. This review describes the distribution and metabolism of these compounds. Caffeine is synthesised from xanthosine derived from purine nucleotides. The major biosynthetic route is xanthosine -&gt; 7-methylxanthosine -&gt; 7-methylxanthine -&gt; theobromine -&gt; caffeine. Degradation activity of caffeine in coffee plants is very low, but catabolism of theophylline is always present. Theophylline is converted to xanthine, and then enters the conventional purine degradation pathway. A recent development in caffeine research is the successful cloning of genes of N-methyltransferases and characterization of recombinant proteins of these genes. Possible biotechnological...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Coffea; Caffeine; Purine alkaloids; Pyridine alkaloids; Theobromine; Trigonelline.
Ano: 2006
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202006000100001

Ethylene production and acc oxidase gene expression during fruit ripening of Coffea arabica L.
Provedor de dados: 61
Autores: Pereira,Luiz Filipe Protasio; Galvão,Rafaelo M.; Kobayashi,Adilson K.; Cação,Sandra Maria B.; Vieira,Luiz Gonzaga Esteves.
The phytohormone ethylene is involved in several physiological and developmental processes in higher plants, including ripening of fruits, abscission of organs and tissues, senescence, wound response as well as in other abiotic stresses. The enzyme 1-aminocyclopropane-1-carboxylate oxidase (ACO) catalyzes the last step of ethylene biosynthesis. The production of ethylene and the expression of a Coffea arabica ACO gene during the last stages of fruit maturation were investigated. A rapid increase of ethylene production at the green-yellow stage of fruit ripening, after the end of endosperm formation, and a decrease of ethylene production at the cherry stage indicates a climacteric phase during ripening. An ACC oxidase (Ca-ACO) from coffee fruit cDNA was...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: ACC oxidase; Climacteric; Coffee; Ethylene; Maturation.
Ano: 2005
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202005000300002

Studies toward the identification of transcription factors in cassava storage root
Provedor de dados: 61
Autores: Souza,Cláudia Regina Batista de; Almeida,Elionor Rita Pereira de; Carvalho,Luiz Joaquim Castelo Branco; Gander,Eugen Silvano.
Transcription factors play important roles in several physiological processes. In recent years many transcription factors have been isolated from plants and they are emerging as powerful tools in the manipulation of plant traits. In this work we initiated studies in order to isolate transcription factors from cassava (Manihot esculenta Crantz), an important tropical and subtropical crop. Our results show three kinds of proteins expressed differentially in cassava storage root and immunologically related to the opaque-2 transcription factor from maize. Southwestern experiments showed two proteins capable of interacting in vitro with the DNA sequence of the be2S1 gene from the Brazil nut tree.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: BZIP; Cis-acting elements; Expression; Gene regulation; Opaque-2; Southwestern.
Ano: 2003
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202003000300006

Physiological and biochemical responses to drought stress in Barbados cherry
Provedor de dados: 61
Autores: Medeiros,David Barbosa; Silva,Elizamar Ciriaco da; Santos,Hugo Rafael Bentzen; Pacheco,Cinthya Mirella; Musser,Rosimar dos Santos; Nogueira,Rejane Jurema Mansur Custódio.
To evaluate physiological genotypic differences between two Barbados cherry genotypes (13- and 14-CPA) under water deficit, initial growth, water relations, and organic solute accumulation were evaluated in an experiment performed using four-month-old seedlings, which were subjected to four water treatments (100, 75, 50, and 25% of field capacity), with five replications. Severe water deficit (25% of field capacity) negatively affected plant height, stem diameter, leaf area, dry matter of the leaves and stem to both genotypes, and root dry matter to genotype 13-CPA. Predawn (Ywpd) and midday leaf water potentials (Ywmd) were reduced in plants grown under 25% of field capacity, only in the genotype 14-CPA. There was not a change in relative water content,...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Malpighia emarginata DC; Soluble organic solutes; Biomass allocation; Water relations; Water deficit.
Ano: 2012
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202012000300005

Epibrassinolide regulated synthesis of polyamines and auxins in Raphanus sativus L. seedlings under Cu metal stress
Provedor de dados: 61
Autores: Choudhary,Sikander P.; Bhardwaj,Renu; Gupta,Bishan D.; Dutt,Prabhu; Kanwar,Mukesh; Arora,Priya.
The effects of various conc of (10-11, 10-9 and 10-7 M) 24-epibrassinolide (24-epiBL) on polyamines and auxins contents was analyzed in 7days old seedlings of Raphanus sativus L. cv. Pusa chetki under copper metal stress. Cu metal (0.2mM) treatment significantly increased endogenous levels of putrescine, spermidine and spermine when compared with control values. Cadaverine content got decreased under metal stress. Endogenous polyamines showed varying levels in seedlings when applying 24-epiBL treatment only. Maximum increase was found in putrescine, cadaverine and spermidine in 10-11, 10-9 and 10-7 M conc of 24-epiBL respectively when applied alone to R. sativus seedlings. However, metal treatment supplemented with 24-epiBL revealed small increase in...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Raphanus sativus; Polyamines; Auxins; Brassinosteriods; Oxidative stress; Heavy metal stress.
Ano: 2009
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202009000100004

Level and distribution of 20-hydroxyecdysone during Pfaffia glomerata development
Provedor de dados: 61
Autores: Festucci-Buselli,Reginaldo A.; Contim,Luis A. S.; Barbosa,Luiz Cláudio A.; Stuart,Jeff J.; Vieira,Roberto F.; Otoni,Wagner C.
The ecdysteroid 20-hydroxyecdysone (20E) is a steroid hormone found in insects and few plants. To analyze its temporal and spatial distribution in Pfaffia glomerata (Amaranthaceae), we selected among 71 accessions, the accession 13 which showed the highest root 20E total quantity (1.48 g/plant root). The 20E was constantly detected in flowers, leaves, stems, and roots, but its percentage was variable throughout its development. The highest 20E percentage was found in flowers (0.82%), roots (0.66%), leaves (0.60%), and stems (0.24%). While stems showed the least variable 20E percentage (0.13% - 0.24%), followed by roots (0.42% - 0.66%), and flowers (0.47% - 0.82%). Leaves showed the greatest 20E percentage variation (0.21% - 0.60%). The stem and leaves 20E...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Pfaffia glomerata (Spreng.) Pedersen; Amaranthaceae; Brazilian ginseng; Phytochemical analysis; Terpenes; Phytoecdysteroid; 20-hydroxyecdysone.
Ano: 2008
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202008000400006

Limitations to photosynthesis at different temperatures in the leaves of Citrus limon
Provedor de dados: 61
Autores: Pimentel,Carlos; Bernacchi,Carl; Long,Steve.
The response of CO2 assimilation rate (A) to the intercellular partial pressure of CO2 (Ci) was measured on intact lemon leaves over a range of temperatures (10 to 40ºC). The A/Ci response shows how change in the leaf temperature alters the activity of ribulose-1,5-bisphosphate (RuBP) carboxylase-oxygenase (Rubisco) and RuBP regeneration via electron transport. The rate of A reached a maximum of 7.9 to 8.9 µmol m-2 s-1 between 25 and 30ºC, while dark respiration (Rd) increased with temperature from 0.4 µmol m-2 s-1 at 10ºC to 1.4 µmol m-2 s-1 at 40ºC. The maximum rates of carboxylation (Vc,max) and the maximum rates of electron transport (Jmax) both increased over this temperature range from 7.5 to 142 µmol m-2 s-1 and from 23.5 to 152 µmol m-2 s-1,...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: A/Ci curves; Gas exchange; Lemon.
Ano: 2007
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202007000200006

Signal transduction, cell division, differentiation and development: towards unifying mechanisms for pattern formation in plants
Provedor de dados: 61
Autores: Dornelas,Marcelo Carnier.
The elaboration of plant form and function depends on the ability of a plant cell to divide and differentiate. The decisions of individual cells to enter the cell cycle, maintain proliferation competence, become quiescent, expand, differentiate, or die depend on cell-to-cell communication and on the perception of various signals. These signals can include hormones, nutrients, light, temperature, and internal positional and developmental cues. In recent years, progress has been made in understanding the molecular control of plant pattern formation, especially in the model plant Arabidopsis thaliana. Furthermore, specific genes have been found that are necessary for normal pattern formation and the control of the rates of cell division and differentiation....
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Cell differentiation; Developmental genetics; Transduction pathways.
Ano: 2003
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202003000100001

Activation of phenylalanine ammonia lyase as a key component of the antioxidative system of salt-challenged maize leaves
Provedor de dados: 61
Autores: Gholizadeh,Ashraf; Kohnehrouz,B. Baghban.
Differential antioxidative activities were assessed in the leaves of two maize inbreds (A-180 and A-619) under salt stress and the subsequent recovery period. Total antioxidation test revealed that in both inbreds, this ability was sharply increased during stress period, but was slowly reverted back to the normal level during recovery. The enzymatic antioxidative analysis showed differential patterns in the activities of catalase, peroxidase and polyphenol oxidase in both maize inbreeds. Comparative analysis of the activity of phenylalanine ammonia lyase (PAL), a key enzyme at the gateway of propanoid biosynthetic pathway, suggested that propanoid compounds might be antioxidants of pivotal importance to the salt-challenged maize antioxidation system. As...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Antioxidation; Maize; Salt stress; PAL; Catalase; Peroxidase; Polyphenol oxidase.
Ano: 2010
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202010000400001

Effect of cobalt on growth, pigments and the photosynthetic electron transport in Monoraphidium minutum and Nitzchia perminuta
Provedor de dados: 61
Autores: El-Sheekh,M.M.; El-Naggar,A.H.; Osman,M.E.H.; El-Mazaly,E.
The unicellular green alga Monoraphidium minutum and the diatom Nitzschia perminuta were cultured under different concentrations of Co2+. Growth and pigment content were slightly increased at low concentrations and inhibited by high Co2+ concentrations. The results concerning the effect of different concentrations of Co2+ on photosynthetic O2 evolution showed a reduction in the amount of O2 evolved by each alga in response to increasing Co2+ concentrations. However, an increase in O2 evolution for both M. minutum and N. perminuta was observed at relatively low Co2+ concentrations. Photosynthetic electron transport in M. minutum was more sensitive to Co2+ toxicity than in N. perminuta. On the other hand, the effect of the heavy metal on respiration showed...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Cobalt; Diatoms; Green algae; Pigments; Photosynthesis.
Ano: 2003
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202003000300005

The influence of water management and environmental conditions on the chemical composition and beverage quality of coffee beans
Provedor de dados: 61
Autores: Silva,Emerson A. da; Mazzafera,Paulo; Brunini,Orivaldo; Sakai,Emílio; Arruda,Flávio B.; Mattoso,Luiz Henrique C.; Carvalho,Cássia R. L.; Pires,Regina Célia M.
The influence of environmental conditions and irrigation on the chemical composition of green coffee beans and the relationship of these parameters to the quality of the beverage were investigated in coffee plantations in the regions of Adamantina, Mococa and Campinas, in the state of São Paulo, Brazil. The chemical composition and physical aspects of green coffee beans produced in the three regions were related through Principal Component Analyses (PCA) to the quality of beverage, as determined by sensorial and electronic analyses. The chemical composition was affected by the environmental conditions. Some differences in cup quality were detected by the electronic method but not by cup tasting. Irrigation was not a major factor affecting chemical...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Air temperature; Beverage; Coffee quality; Nitrogen compounds.
Ano: 2005
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202005000200006

Chill-induced changes in fatty acid composition of tonoplast vesicles from hypocotyls of Vigna unguiculata (L.) Walp.
Provedor de dados: 61
Autores: Oliveira,Luciana M. N. de; Sobreira,Alana C. de M.; Monteiro,Fernando de P.; Melo,Dirce F. de.
The present study was undertaken to investigate the changes induced by chilling on fatty acid composition of tonoplast vesicles from hypocotyls of Vigna unguiculata (L.) Walp. The 7 day-old control seedlings were grown at 25°C while treated seedlings were submitted to low temperatures (10°C and 4°C) for 4 days after 3 days germination. The chilling stress resulted in a differential inhibition of plant growth at 10°C and 4°C. Following chilling at 10°C and 4°C, the rate of unsaturated to saturated fatty acids increased under chilling stress. Our results suggest that the increase of unsaturated fatty acids content as well as the higher rate unsaturated/saturate fatty acidsmight be used by V. unguiculata plants as an adaptation mechanism likely to maintain...
Tipo: Info:eu-repo/semantics/other
Palavras-chave: Chilling; Cowpea; Lipid; Fatty acids; Membrane; Vacuole.
Ano: 2010
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202010000100008

Increasing plant longevity and associated metabolic events in potted carnation (Dianthus caryophyllus L. Clove Pink)
Provedor de dados: 61
Autores: Karimi,Mahnaz; Asil,Moazzam Hassanpour; Zakizadeh,Hedayat.
The effects of aminooxyacetic acid, benzyladenine, and 1-methylcyclopropene treatments on the post-production flower quality of potted carnation plants (Dianthus caryophyllus L. Clove Pink) were investigated considering ethylene production and antioxidant metabolism. Maximum plant longevity (17 days) was obtained using 70 ppb of 1-methylcyclopropene. As compared to control plants, ethylene production was significantly decreased by aminooxyacetic acid at concentrations over 100 mg L-1, benzyladenine at 20 or 30 mg L-1, and 1-methylcyclopropene at 70 and 140 ppb. A significant increase in 1-aminocyclopropane-1-carboxylic-acid concentration was observed in 1-methylcyclopropene treated plants compared with the control ones. On the other hand, decline in...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Aminooxyacetic acid; Benzyladenine; Ethylene production; Flower; 1-methylcyclopropene.
Ano: 2012
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202012000400003

From leaf to flower: revisiting Goethe's concepts on the ¨metamorphosis¨ of plants
Provedor de dados: 61
Autores: Dornelas,Marcelo Carnier; Dornelas,Odair.
Goethe’s seminal scientific work, Versuch die Metamorphose der Pflanzen zu erklaren (An Attempt to Interpret the Metamorphosis of Plants) dated from 1790, has created the foundations for many domains of modern plant biology. The archetypal leaf concept, which considers floral organs as modified leaves, besides being the best known has been proven true, following the description of the ABC molecular model of floral organ identity determination during the last decade. Here we analyze the whole theoretical frame of Goethe’s 1790 publication and present two previously misconsidered aspects of this work: The "refinement of the sap" concept as a directional principle and the "cycles of contractions and expansions" as cycles of differential determination of the...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Flower development; Gene expression; Meristem behavior; Theory of plant development.
Ano: 2005
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202005000400001

Shoot-foliage relationships in deciduous, semideciduous, and evergreen cerrado tree species
Provedor de dados: 61
Autores: Souza,João Paulo; Prado,Carlos Henrique B. A.; Albino,Ana Lúcia S.; Damascos,Maria A.
The morphology and the biomass allocation in shoots and leaves were investigated in 15 cerrado tree species with distinct leaf phenology growing under natural conditions. Higher values of leaf/shoot ratio on mass base, individual leaf area, leaf area per shoot, leaf display index, and leaf number per shoot length were found in deciduous than in evergreen species. The differences about shoot-foliage relationship across leaf phenological groups could be explained by plagiotropic shoots on deciduous and by erect shoots in semideciduous and evergreen species. Plagiotropic shoots allow similar irradiance along shoots and high biomass allocation in favor of leaves without foliage self-shading in deciduous tree species. The structural differentiation between...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Biomass allocation; Cerrado; Deciduousness; Irradiance; Leaf area; Orthotropic; Plagiotropic; Shoot.
Ano: 2009
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202009000100009

Nickelophilous plants and their significance in phytotechnologies
Provedor de dados: 61
Autores: Prasad,Majeti Narasimha Vara.
Nickeliferous soils are invaded predominantly by members of the Brassicaceae, Cyperaceae, Cunoniaceae, Caryophyllaceae, Fabaceae, Flacourtiaceae, Euphorbiaceous, Lamiaceae, Poaceae and Violaceae, and many of these plants are metal tolerant. About 300 Ni hyperaccumulating plants been identified. These members exhibit unusual appetite for toxic metals and elemental defense. Hyperaccumulators provide protection against fungal and insect attack. Investigations suggested that Ni-hyperaccumulation has a protective function against fungal and bacterial pathogens in Streptanthus polygaloides and Thlaspi montanum. Significance of nickelophilous plants and their significance in phytotechnologies are discussed in this paper.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Heavy metal; Hyperaccumulators; Nickel; Phytomanagement; Tolerance.
Ano: 2005
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202005000100010

Genetic transformation of coffee
Provedor de dados: 61
Autores: Ribas,Alessandra Ferreira; Pereira,Luiz Filipe Protasio; Vieira,Luiz Gonzaga E.
In the last 15 years, considerable advances were made in coffee genetic transformation. Different research groups in the world have been able to transform coffee with genes for insect resistance, decaffeinated coffee, herbicide resistance and control of fruit maturation. Although the majority of the research is still limited to laboratory and greenhouse studies, initial field tests with transformed coffee are beginning to appear in the literature. In this review we provide an update on the state of coffee genetic transformation, presenting technical aspects related to tissue culture systems, strategies for selection and transformation with particle bombardment, as well as the use of Agrobacterium tumefaciens. We also discuss the potential applications of...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Agrobacterium; Coffea; Biolistic; Genetic engineering; Transgenic.
Ano: 2006
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202006000100007

Chlorophyll a fluorescence of sweet potato plants cultivated in vitro and during ex vitro acclimatization
Provedor de dados: 61
Autores: Cassana,Francine F.; Falqueto,Antelmo R.; Braga,Eugenia J. B.; Peters,Jose A.; Bacarin,Marcos A.
Sweet potato (Ipomoea batatas L.) plants were cultivated in vitro in Murashige and Skoog (MS) medium with 20 and 40 g L-1 of sucrose under two different photon flux densities (21 and 60 µmol m-2 s-1). Leaves developed in vitro mostly showed high variable to maximum fluorescence ratio (F V/F M) , indicating good development of photosynthetic apparatus. This ratio decreased during leaf aging, especially in the plants cultivated in vitro on medium with higher sucrose concentration and higher photon flux. Leaves developed ex vitro showed high F V/F M ratio during whole experiment. The effective photochemical efficiency (F V'/F M') was maximum at 15th day after emergence of leaves. Photosynthetic potential rate was higher in leaves developed in vitro than in...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Culture medium; Photon flux density; Photosystem; Sucrose.
Ano: 2010
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202010000300003

Alterations in fatty acid composition due to cold exposure at the vegetative stage in rice
Provedor de dados: 61
Autores: Cruz,Renata Pereira da; Golombieski,Jaqueline Ineu; Bazana,Maiara Taís; Cabreira,Caroline; Silveira,Taíse Foletto; Silva,Leila Picolli da.
Rice is a tropical plant, so cold temperature may be detrimental to its development, depending on the genotype and environmental conditions. Degree of lipid unsaturation has been related to cold tolerance due to its effect on membrane stability. So, the aim of this study was to characterize the fatty acid composition and its alterations due to cold temperature in rice genotypes of diversified origin. Forty-four rice genotypes at the V4 stage were submitted to two temperature conditions: 10°C and 28°C for two days and after this they had their leaves collected for lipid extraction and quantification. Control plants were allowed to regrow until presenting four leaves fully expanded and then were subjected to 10°C for ten days for cold tolerance evaluation....
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Oryza sativa L.; Lipid; Linolenic acid; Cold tolerance; Membrane stability; Plant survival.
Ano: 2010
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202010000300007

Efeito da aplicação de zinco via foliar na síntese de triptofano, aminoácidos e proteínas solúveis em mudas de cafeeiro
Provedor de dados: 61
Autores: Malta,Marcelo Ribeiro; Furtini Neto,Antônio Eduardo; Alves,José Donizeti; Guimarães,Paulo Tácito Gontijo.
Avaliou-se, neste trabalho, o efeito da aplicação de Zn via foliar na síntese de triptofano, aminoácidos totais e proteínas solúveis totais em mudas de cafeeiro (Coffea arabica L.). Cultivaram-se as mudas em solução nutritiva sem Zn durante quatro meses e após esse período, pulverizaram-se as plantas com ZnSO4.7H2O a 0,6 %, definindo-se os tratamentos segundo a posição de aplicação (basal: 6 pares de folhas inferiores, ou apical: 6 pares de folhas superiores, além dos ramos plagiotrópicos). As plantas foram coletadas nos tempos: 0 (testemunha), 12, 24, 48 ou 72 h após aplicação de Zn, separando-se as folhas da região apical, basal e dos ramos plagiotrópicos. Determinaram-se as concentrações foliares de triptofano, aminoácidos totais e proteínas solúveis...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Coffea arabica; Metabolismo; Proteína; Triptofano.
Ano: 2002
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202002000100004

28-Homobrassinolide alleviates oxidative stress in salt-treated maize (Zea mays L.) plants
Provedor de dados: 61
Autores: Arora,Nitika; Bhardwaj,Renu; Sharma,Priyanka; Arora,Hardesh K.
Tipo: Info:eu-repo/semantics/other
Ano: 2008
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202008000200007

Response of Crotalaria juncea to nickel exposure
Provedor de dados: 61
Autores: Cardoso,Patrícia Felippe; Gratão,Priscila Lupino; Gomes-Junior,Rui Alberto; Medici,Leonardo Oliveira; Azevedo,Ricardo Antunes.
The response of Crotalaria juncea seedlings to nickel (Ni) was investigated. Ni was shown to accumulate mainly in the root system, with little being translocated to the shoots. Catalase (CAT) and glutathione reductase (GR) responses to Ni were also analyzed. CAT activity did not exhibit a clear trend in response to Ni exposure, whereas GR activity appeared to respond to the stress induced by Ni. The results suggest that in C. juncea GR participates in the detoxification of Ni-induced reactive oxygen species via the glutathione-ascorbate cycle.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Antioxidant enzymes; Heavy metals; Nickel; Reactive oxygen species.
Ano: 2005
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202005000200010

Evidence of an endogenous lectin receptor in seeds of the legume Cratylia floribunda
Provedor de dados: 61
Autores: Ramos,Márcio Viana; Bomfim,Liezelotte Rezende; Bandeira,; Debray,Henri.
Cratylia floribunda seeds were ground and the clean crude saline extract was fractionated into albumin, globulin, prolamin, acidic and basic glutelin protein fractions. These protein fractions were examined for the presence of an endogenous lectin receptor by SDS-polyacrylamide gel electrophoresis, western blot, affinity chromatography on a Sepharose 4B-Cratylia floribunda (CFL) lectin column and kinetic analysis in real time by surface plasmon resonance (SPR). Prolamin was the richest protein fraction although very poor in haemagglutinating activity. Basic glutelin was far the less interesting fraction for lectin activity and protein content, even though this fraction contains considerable amounts of carbohydrates. Lectin was present in all protein...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Protein-carbohydrate interaction; Surface plasmon resonance; Western blot.
Ano: 2002
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202002000300003

Antioxidant system response induced by aluminum in two rice cultivars
Provedor de dados: 61
Autores: Ribeiro,Cleberson; Cambraia,José; Peixoto,Paulo Henrique Pereira; Fonseca Júnior,Élcio Meira da.
The antioxidant defense system response was evaluated in two rice cultivars (Oryza sativa L.), Fernandes (CNA-1158) and Maravilha (CNA-6843-1), treated with toxic levels of aluminum. After exposure to aluminum we determined plant growth, H2O2 and O2•- contents, lipid peroxidation, antioxidant enzymes activities and ascorbate and dehydroascorbate contents. Al predominantly accumulated in roots of both cultivars but it reduced root and shoot growth only in the Maravilha cultivar. Treatment with aluminum resulted in a reduction of 84 and 60% in the levels of H2O2 in the roots of the cultivars Maravilha and Fernandes, respectively, and of 26% in the levels of O2•- only in the roots of Fernandes cultivar. Increased lipid peroxidation was observed only in the...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Aluminum; Enzymes; Reactive oxygen species; Oryza sativa; Oxidative stress.
Ano: 2012
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202012000200004

Plant-insect interactions: an evolutionary arms race between two distinct defense mechanisms
Provedor de dados: 61
Autores: Mello,Marcia O.; Silva-Filho,Marcio C.
In this review, plant-insect interaction is discussed as a dynamic system, subjected to continual variation and change. Plants developed different mechanisms to reduce insect attack, including specific responses that activate different metabolic pathways which considerably alter their chemical and physical aspects. On the other hand, insects developed several strategies to overcome plant defense barriers, allowing them to feed, grow and reproduce on their host plants. This review foccuses on several aspects of this complex interaction between plants and insects, including chemical-derived substances, protein-derived molecules and volatile compounds of plants whereas metabolization, sequestration or avoidance are in turn employed by the insects.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Adaptation; Co-evolution; Herbivory.
Ano: 2002
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202002000200001

Ascorbic acid biosynthesis: a precursor study on plants
Provedor de dados: 61
Autores: Barata-Soares,Anderson D.; Gomez,Maria Luiza P. A.; Mesquita,Carlos Henrique de; Lajolo,Franco M.
Since the first isolation of ascorbic acid (AsA) in 1928, few papers have been published regarding the biosynthesis of AsA in plants, especially in fruits. It took as long as 1998, before Wheeler, Jones and Smirnoff, based on a study with Arabidopsis leaves, proposed what can be considered the main pathway of biosynthesis of AsA, in which L-galactose (L-GAL) is a key precursor. This paper reports the effectiveness of some precursors (cold or radiolabeled) in the biosynthesis of AsA in different plants: green sweet pepper, white-pulp guava, red-pulp guava, papaya and strawberry at two ripening stages (mature green and ripe for papaya and mature green and half red for strawberry) and broccoli. The 'Smirnoff-Wheeler' pathway was functioning and active in all...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Ascorbate; Ascorbate biosynthesis pathway; Antioxidant; Precursor infiltration.
Ano: 2004
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202004000300004

Expression analysis of a set of genes related to the ripening of bananas and mangoes
Provedor de dados: 61
Autores: Godoy,Adriana de; Morita,Rodrigo J.; Cordenunsi,Beatriz R.; Lajolo,Franco M.; Nascimento,João Roberto O. do.
During ripening many important physic-chemical changes contribute to fruit quality, and they are precisely determined by gene expression. Specific genes are essential to normal ripening; however, information on gene expression about the majority of tropical fruit, such as bananas and mangoes is limited. In this way, the present study was undertaken with the objective to provide preliminary access to the changes in expression of some genes potentially relevant to banana and mango ripening. To simultaneously evaluate the changes in gene expression, a small collection of genes related to ethylene biosynthesis, starch mobilization, cell wall disassembly, pigment synthesis and ascorbate metabolism was assembled in nylon membranes and probed with cDNA from...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Fruit ripening; Reverse northern blotting.
Ano: 2009
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202009000400001

The complexity-stability hypothesis in plant gas exchange under water deficit
Provedor de dados: 61
Autores: Souza,Gustavo M.; Pincus,Steven M; Monteiro,José Alberto F.
We hypothesized that more complex, i.e. irregular, temporal dynamics and a more interconnected overall network supports greater stability to gas exchange parameters (herein, CO2 net assimilation and transpiration) in plants under water deficit. To test this hypothesis two genotypes of Phaseolus vulgaris were subjected to a period of absence of irrigation, and subsequent rewatering to achieve recovery. Gas exchanges parameters were measured each 10 s during 6 h to obtain time series to evaluate complexity by Approximate Entropy (ApEn) calculations, and network connectance in each water regime. Notably, the Jalo Precoce genotype showed significantly more stability than the Guarumbé genotype under system perturbation, coincident with greater irregularity in...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Approximate Entropy; Complexity; Network connectance; Plant stress theory; Photosynthesis; Temporal dynamics; Water deficit.
Ano: 2005
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202005000400004

Purification and structural stability of a trypsin inhibitor from Amazon Inga cylindrica [Vell.] Mart. seeds
Provedor de dados: 61
Autores: Calderon,Leonardo A; Almeida Filho,Humberto A; Teles,Rozeni C. L; Medrano,Francisco J; Bloch Jr,Carlos; Santoro,Marcelo M; Freitas,Sonia M.
Inga cylindrica Trypsin Inhibitor (ICTI) was purified as a single polypeptide chain by one step anion-exchange chromatography from a crude extract of Inga cylindrica (Vell.) Mart. seeds. ICTI is a 19.5 kDa protein presenting a remarkable inhibitory activity against bovine trypsin (EC 3.4.21.4) (Ki = 4.3 nM). Circular dichroism analysis revealed that this inhibitor is a β type protein (40.4% of β-strand; 24.6% of β-turn and 6.7% of α-helix) in accordance with properties displayed in Kunitz type inhibitors. ICTI is a thermal stable protein within a wide range of pH (1.6 to 10.0) exhibiting highest stability at pH 7.0 as indicated by Tm of 70.0 ºC and ΔG25 of 48.5 ± 0.7 kJ.mol-1. The values of ΔG25 at pH 1.6 (22.5 ± 1.2 kJ.mol-1) and pH 10.0 (31.5 ± 1.0...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Inga cylindrica [Vell.] Mart; Leguminosae; Mimosoideae; Protease inhibitor; Protein stability; Trypsin inhibitor.
Ano: 2010
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202010000200001

Ecophysiology of coconut palm under water stress
Provedor de dados: 61
Autores: Gomes,Fábio P.; Prado,Carlos H.B.A.
Coconut palm is of great social and economic importance for millions of people in the tropics and subtropics. Drought is one of the main environmental factors that limit coconut productivity. In this review, physiological and morphological data are presented in an integrated perspective to provide a holistic view of the behavior of coconut trees facing water deficit under both field and controlled conditions. Great capacity to produce homorhizic roots capable of searching continuously for water and nutrients and high protoplasmic tolerance in leaves allows the coconut tree to endure water deficit. High membrane stability, osmoprotection, osmoregulation and enhanced activity of antioxidant enzymes are characteristics often found in leaves of...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Cocus nucifera; Desiccation tolerance; Leaf gas exchange; Leaf water relations; Net photosynthesis; Osmotic potential; Water potential; Water-use efficiency.
Ano: 2007
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202007000400008

Partitioning of nitrate reductase activity in Coffea arabica L. and its relation to carbon assimilation under different irradiance regimes
Provedor de dados: 61
Autores: Carelli,Maria Luiza C.; Fahl,Joel I.
The distribution of in vivo nitrate reductase (EC 1.6.6.1) activity (NRA) between leaves and roots was studied in young coffee plants (Coffea arabica L.) grown in pots with watered sand in a glasshouse and irrigated with nutrient solution. The influence of irradiance regimes on the partitioning of NRA, and its relation with CO2 assimilation, was also evaluated in plants grown under approximately 20, 50 and 100% of full sunlight. Time-course of nitrate accumulation in nitrogen-starved plants showed a similar pattern in leaves and roots after supplying 15 mmol L-1 nitrate, indicating efficient ability of the roots to export nitrate to the shoot. At the same time, NRA was rapidly induced in both tissues. In shoots, NRA partitioning was synchronized among the...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Coffee; Growth; Leaf/root ratio; Nitrate assimilation; Photosynthesis; Shading.
Ano: 2006
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202006000300006

Differential water uptake kinetics in axes and cotyledons during seed germination of Vigna radiata under chilling temperature and cycloheximide treatment
Provedor de dados: 61
Autores: Chakraborty,R.; Kar,R.K.
Water uptake kinetics of axes and cotyledons of Vigna radiata seeds has been studied during incubation at chilling temperature (4°C) and under cycloheximide treatment. Germination rate of scarified seeds was faster than intact seeds, which can be correlated with their comparative water uptake kinetics. Chilling temperature during incubation significantly slowed down water uptake by both intact and scarified seeds. Treatment with cycloheximide was also somewhat effective in retarding water uptake, but only in scarified seeds. Water uptake by axes isolated from intact seeds (attached or detached from the cotyledons) was inhibited completely by chilling temperature as well as by cycloheximide treatment while these treatments were ineffective in preventing...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Chilling treatment; Cycloheximide; Germination; Water uptake; Vigna radiata seeds.
Ano: 2008
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202008000400003

Glycinebetaine improves salt tolerance in vinal (Prosopis ruscifolia Griesbach) seedlings
Provedor de dados: 61
Autores: Meloni,Diego A.; Martínez,Carlos A.
Glycinebetaine (GB) is a very important organic osmolyte that accumulates in a number of diverse groups of plants in response to environmental stress. In some plants, increased resistance to drought, salinity and low temperature has been achieved through exogenous application of GB. In this study, the effect of exogenously applied GB (8 mM) on the ability of vinal (Prosopis ruscifolia G.) plants to withstand NaCl stress was investigated. The dry biomass of vinal showed a decrease under salt stress, but in GB-treated plants exposed to the same stress, this reduction was mitigated. Sodium accumulated in the leaves of plants grown under saline conditions, but the addition of GB to salt-grown plants reduced Na+ content by 40%. Salinity significantly reduced...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Lipid peroxidation; Salt stress; Superoxide dismutase.
Ano: 2009
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202009000300007

Phosphorus and nitrogen interaction: loss of QC identity in response to P or N limitation is antecipated in pdr23 mutant
Provedor de dados: 61
Autores: Costa,Cibele T.; Strieder,Mércio L.; Abel,Stephen; Delatorre,Carla A.
Changes in root architecture are an important adaptive strategy used by plants in response to limited nutrient availability to increase the odds of acquiring them. The quiescent center (QC) plays an important role by altering the meristem activity causing differentiation and therefore, inducing a determinate growth program. The arabidopsis mutant pdr23 presents primary short root in the presence of nitrate and is inefficient in the use of nucleic acids as a source of phosphorus. In this study the effect of the pdr23 mutation on the QC maintenance under low phosphorus (P) and/or nitrogen is evaluated. QC identity is maintained in wild-type in the absence of nitrate and/or phosphate if nucleic acids can be used as an alternative source of these nutrients,...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: QC25::iudA; Nutrient deficiency; Root development; Determinate root growth program; Stress.
Ano: 2011
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202011000300006

Nucleotide diversity of a major carotenoid biosynthetic pathway gene in wild and cultivated Solanum (Section Lycopersicon) species
Provedor de dados: 61
Autores: Araújo,Ana H.; Fonseca,Maria Esther de N.; Boiteux,Leonardo S.
A polymerase chain reaction (PCR)-based approach was employed to isolate putative alleles of the chromoplast-specific lycopene beta-cyclase (CYCB) gene from wild and cultivated tomatoes [Solanum (Section Lycopersicon)]. The objective of this work was to establish an effective PCR protocol by testing DNA samples from distinct germplasm accessions with a primer pair designed to selectively target conserved regions present in the available CYCB sequences. This PCR optimization allowed the amplification of 1219 out 1666 bp of the gene in six taxa: S. cheesmaniae, S. peruvianum, S. neorickii, S. pennellii, S. pimpinellifolium and S. lycopersicum. Sixty-three mutation sites (31 transitions, 18 transversions and 14 single base deletions/insertions) were detected...
Tipo: Info:eu-repo/semantics/other
Palavras-chave: CYCB; Lycopene; Lycopene-beta-cyclase; Nucleotide diversity; Tomatoes; Molecular markers.
Ano: 2007
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202007000300007

Effects of salt stress on plant growth, stomatal response and solute accumulation of different maize genotypes
Provedor de dados: 61
Autores: Azevedo Neto,André Dias de; Prisco,José Tarquinio; Enéas-Filho,Joaquim; Lacerda,Claudivan Feitosa de; Silva,José Vieira; Costa,Paulo Henrique Alves da; Gomes-Filho,Enéas.
Seeds from eight different maize genotypes (BR3123, BR5004, BR5011, BR5026, BR5033, CMS50, D766 and ICI8447) were sown in vermiculite, and after germination they were transplanted into nutrient solution or nutrient solution containing 100 mmol.L-1 of NaCl and placed in a greenhouse. During the experimental period plant growth (dry matter, shoot to root dry mass ratio, leaf area, relative growth rate, and net assimilation rate), leaf temperature, stomatal conductance, transpiration, predawn water potential, sodium, potassium, soluble amino acids and soluble carbohydrate contents were determined in both control and salt stressed plants of all genotypes studied. Salt stress reduced plant growth of all genotypes but the genotypes BR5033 and BR5011 were...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Growth analysis; Osmoregulation; Salinity; Transpiration; Zea mays; Water relations.
Ano: 2004
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202004000100005

EgLFY, the Eucalyptus grandis homolog of the Arabidopsis gene LEAFY is expressed in reproductive and vegetative tissues
Provedor de dados: 61
Autores: Dornelas,Marcelo Carnier; Amaral,Weber A. Neves do; Rodriguez,Adriana Pinheiro Martinelli.
The EgLFY gene cloned from Eucalyptus grandis has sequence homology to the floral meristem identity gene LEAFY (LFY) from Arabidopsis and FLORICAULA (FLO) from Antirrhinum. EgLFY is preferentially expressed in the developing eucalypt floral organs in a pattern similar to that described previously for the Arabidopsis LFY. In situ hybridization experiments have shown that EgLFY is strongly expressed in the early floral meristem and then successively in the primordia of sepals, petals, stamens and carpels. It is also expressed in the leaf primordia of adult trees. The expression of the EgLFY coding region under control of the Arabidopsis LFY promoter could complement strong lfy mutations in transgenic Arabidopsis plants. These data suggest that EgLFY plays a...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Eucalyptus; Flowering; LEAFY; Reproductive development.
Ano: 2004
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202004000200006

Synergistic response of auxin and ethylene on physiology of Jatropha curcas L.
Provedor de dados: 61
Autores: Joshi,Gargi; Shukla,Arvind; Shukla,Alok.
Jatropha curcas L. is a versatile crop since all its plant material is brought to use either as energy source, industrial or medicinal purpose. Several studies are ongoing in different parts of the world to optimize, enhance and exploit the growth, fruiting cycle and different developmental stages of the plant so that the economic yield of the plants can be utilized to the fullest limits. Foliar application of plant growth regulators such as ethrel (an ethylene releasing compound), indole acetic acid (IAA) and naphthalene acetic acid (NAA) at 50, 100 and 150 ppm, was found to influence different morpho-physiological characters in Jatropha curcas L, such as plant height, collar diameter, tree spread, flower initiation, number of inflorescence per plant,...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Jatropha curcas; Auxin; Ethrel; Synergism; Morpho-physiological.
Ano: 2011
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202011000100009

Preface: Toxic metals in plants
Provedor de dados: 61
Autores: Azevedo,Ricardo A.; Lea,Peter J.
Tipo: Info:eu-repo/semantics/other
Ano: 2005
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202005000100001

Nitrate uptake and metabolism by roots of soybean plants under oxygen deficiency.
Provedor de dados: 61
Autores: Brandão,Andrea D.; Sodek,Ladaslav.
Nitrate is reported to improve tolerance of plants towards oxygen deficiency enabled by waterlogging of the root system, but the mechanism underlying the phenomenon remains poorly understood. We studied the metabolism of nitrate in roots exposed to hypoxia, using soybean plants growing in a hydroponic system after suspending aeration and covering the surface of the nutrient solution with mineral oil. Nitrate depletion from the medium was more intense under hypoxia than normoxia, but in the presence of chloramphenicol, consumption under hypoxia was significantly reduced. Nitrite accumulated in the medium in the state of hypoxia and this effect was partially eliminated by chloramphenicol. Nitrate consumption sensitive to chloramphenicol was attributed to...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Glycine max; Hypoxia; Nitrate reductase; Nitrite; Waterlogging.
Ano: 2009
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202009000100003

Seasonal leaf gas exchange and water potential in a woody cerrado species community
Provedor de dados: 61
Autores: Prado,Carlos Henrique Britto de Assis; Wenhui,Zhang; Cardoza Rojas,Manuel Humberto; Souza,Gustavo Maia.
Predawn leaf water potential (psipd) and morning values of leaf gas exchange, as net photosynthesis (A), stomatal conductance (gs), transpiration (E), and morning leaf water potential (psimn) were determined seasonally in 22 woody cerrado species growing under natural conditions. Despite the lower mean values of psipd in the dry season (-0.35 ± 0.23 MPa) compared to the wet season (-0.08 ± 0.03 MPa), the lowest psipd in the dry season (-0.90 ± 0.00 MPa) still showed a good nocturnal leaf water status recovery for all species studied through out the year. Mean gs values dropped 78 % in the dry season, when the vapor pressure of the air was 80% greater than in the wet season. This reduction in gs led to an average reduction of 33% in both A and E, enabling...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Cerrado; Deciduousness; Network connectance; Stomatal conductance; Photosynthesis.
Ano: 2004
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202004000100002

Utilization of the chlorophyll a fluorescence technique as a tool for selecting tolerant species to environments of high irradiance
Provedor de dados: 61
Autores: Gonçalves,José Francisco de Carvalho; Santos Júnior,Ulysses Moreira dos.
We examine the hypothesis that the chlorophyll a fluorescence technique can be an efficient tool to support the selection of species adapted to high irradiance and therefore, suitable for use in initial rehabilitation projects of degraded areas. The experiment was conducted at the Pedro de Moura Operational Base, Amazonas, Brazil. The fluorescence transients were obtained using a portable fluorometer for leaves of Bombacopsis macrocalyx (Bm), Eugenia cumini (Ec), Iryanthera macrophyla (Im) and Senna reticulata (Sr), which were subjected to high irradiance between 12:00 am and 1:00 p.m. Using the OJIP test, the following were calculated: performance index (PI ABS), density of reaction centres per cross section (RC/CS), maximum efficiency of photosystem II...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Degraded areas; Energy flux; Performance index.
Ano: 2005
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202005000300005

Foliar nitrogen and changes in free amino acid composition of Solanum lycopersicum under cadmium toxicity: kinetics of 15NH4+
Provedor de dados: 61
Autores: Haouari,Chiraz Chaffei; Nasraoui,Afef Hajjaji; Carrayol,Elisa; Lelendais,Maud; Ghorbel,Mohamed Habib; Gouia,Houda.
Glutamate metabolism and amino acid translocation were investigated in the control and cadmium stressed shoots of tomato (Solanum lycopersicum - 63/5 F1), using (15N) ammonium and (15N) glutamate tracers. Regardless of organ type, [15N] ammonium assimilation occurred via glutamine synthetase (EC 6.3.1.2), in the control and stressed plants, and it did not depend on glutamate dehydrogenase (EC 1.4.1.2). The [15N] ammonium and ammonium accumulation patterns support the role of glutamate dehydrogenase in the deamination of [15N] glutamate to provide 2-oxoglutarate and [15N] ammonium. In the presence of cadmium, excess [15N] ammonium was incorporated into asparagine, which served as an additional detoxification molecule. In the presence both of methionine...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Ammonium; Glutamate dehydrogenase; Methionine sulfoximine; 15N-NH4+.
Ano: 2012
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202012000100004

Monitoring the end of the in vitro phase of Anthurium andreanum Lindl. plantlets
Provedor de dados: 61
Autores: Stancato,Giulio Cesare; Tucci,Maria Luiza Sant’Anna.
Estimulation of autotrophy in in vitro plantlets could be achieved through changes in the culture medium, or by changing the traditional hermetic caps by one that could allow gas exchanges between the culture and the environment. Besides that, the use of lamps with distinct emission spectrum irradiaction has propitiated successful results. This work was carried out aiming to evaluate the either the combined or the single action of some factors that can induce autotrophy on in vitro A. andraeanum cv. Eidibel plantlets. 3 sucrose concentrations were used: 0, 15 and 60 mM and for each one, to kinds of flasks according to the cap ventilation: under (0.038 L.h-1) and without ventilation. Flasks were kept under cold light fluorescent lamps or under gro-lux...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Acclimatization; Araceae; Plantlets metabolism.
Ano: 2010
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202010000100007

Strategies to increase zinc deficiency tolerance and homeostasis in plants
Provedor de dados: 61
Autores: Henriques,Ariadne Ribeiro; Chalfun-Junior,Antonio; Aarts,Mark.
Zinc deficiency is a global problem of considerable importance for agriculture and human health. Under zinc deficiency conditions, many essential zinc-dependent physiological functions are unable to operate normally, and the cellular homeostasis is adversely affected. This paper described the potential damages that low-zinc bioavailability in soil can have for plants, humans, and animals. In addition, current knowledge on physiological and molecular aspects of zinc homeostasis in plants and strategies used to increase zinc deficiency tolerance were discussed.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Biofortification; Mineral nutrition; Plant abiotic stress; Plant nutrition.
Ano: 2012
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202012000100002

Environmental drivers of leaf phenology in trees of the tropical species Ficus obtusifolia
Provedor de dados: 61
Autores: Ballestrini,Caín; Tezara,Wilmer; Herrera,Ana.
Vegetative as well as reproductive phenology of tropical trees frequently occur synchronously at the end of the dry season. It has been repeatedly observed on two individuals of the tropical species Ficus obtusifolia growing in Caracas that they lose their entire foliage in a period of 48 h during the dry season and renew it within the next 72 h. In order to gain knowledge on the mechanisms that govern leaf exchange in F. obtusifolia, we followed in these two individuals the seasonal changes in leaf and fruit phenology, water relations and environmental variables, and in another 25, phenology only. Although foliar exchange was always observed before the rainy season, it also occurred near the end of the rainy season. An increase in leaf turgor potential of...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Brevi-deciduous; Day length; Leaf fall; Sap flow velocity; Water relations.
Ano: 2011
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202011000200003

Changes in lipid profile during growth and senescence of Catharanthus roseus leaf
Provedor de dados: 61
Autores: Mishra,Sanjay; Tyagi,Abhishek; Singh,I.V.; Sangwan,R.S.
Various lipid classes and compounds were monitored during the period of leaf emergence to leaf drop of Catharanthus roseus. The expansion to early maturation phase was accompanied by cellular build-up of all major lipid classes, whilst aging and senescence were characterized by their substantial decline, except for the neutral lipids; the leaf monogalactosyl diglyceride/digalactosyl diglyceride ratio decreased from 4.3 (complete maturity) to 2.1 (abscised stage). The early maturation stage was the earliest stage when appreciable amounts of free sterols and fatty acids could be observed. Sterol/phospholipids ratios increased by 68-fold in the abscised leaf as compared to that at full maturity. The unsaturated/saturated fatty acid ratio was far lower in the...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Catharanthus roseus; Glycolipids; Leaf development; Phospholipids; Senescence; Sterol.
Ano: 2006
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202006000400002

Ecophysiological responses to drought and salinity in the cosmopolitan invader Nicotiana glauca
Provedor de dados: 61
Autores: González,Armando; Tezara,Wilmer; Rengifo,Elizabeth; Herrera,Ana.
Nicotiana glauca, a shrub native to southern South America, is widely distributed in the Americas, from Patagonia to the USA, from zero up to 3,700 m; it rapidly invades disturbed environments. In Venezuela, it has been reported from zero up to 2,000 m growing in contrasting conditions of relative humidity, temperature, rainfall, and salinity. In order to gain insight into the extent and mode of resistance to drought and salinity in N. glauca, we studied the effect of these factors on water relations and photosynthesis under both natural and greenhouse conditions. In the field, water potential, photosynthetic rate (A) and stomatal conductance (gs), but not relative water content (RWC) decreased because of drought. Manual removal of epicuticular wax...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Drought; Osmotic adjustment; Salinity; Water deficit.
Ano: 2012
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202012000300008

Physiological responses of Eichhornia crassipes [Mart.] Solms to the combined exposure to excess nutrients and Hg
Provedor de dados: 61
Autores: Caldelas,Cristina; Iglesia-Turiño,Santiago; Araus,Jose L.; Bort,Jordi; Febrero,Anna.
In the present study the physiological response of water hyacinth (Eichhornia crassipes [Mart.] Solms) to the combined exposure of excess nutrients and Hg was examined. Young water hyacinth plants were exposed to a range of HgCl2 and KNO3 concentrations. After eight weeks, submerged plant tissues reached an Hg concentration of 4 mg g-1. The accumulation of P and S was reduced by the addition of HgCl2, and also the P and K concentrations in emerged and submerged parts decreased. In contrast, the addition of HgCl2 increased Ca and Mg concentrations in submerged parts. Furthermore, the concentration ratios of submerged/emerged parts for Ca, Mg and P were also reduced by the addition of HgCl2. The interaction of HgCl2 and KNO3 was synergistic and decreased...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Abiotic stress; Metal accumulation; Multiple stress; Phytoremediation; Water eutrophication; Water pollution.
Ano: 2009
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202009000100002

Photosynthetic activity in the rootstock of hybrid peach trees submitted to water restriction and flooding
Provedor de dados: 61
Autores: Martinazzo,Emanuela G.; Perboni,Anelise T.; Farias,Márcio E.; Bianchi,Valmor J.; Bacarin,Marcos A.
This study aimed to evaluate the effect of flooding and water restriction (drought) on the photosynthetic activity in plants of the hybrid rootstock 'GxN-9' (Prunus dulcis Mill. × Prunus persica L. Bastsch), grown in a greenhouse. Chlorophyll fluorescence and gas exchange were analyzed in plants of approximately 12 months. The reduction of photosynthetic activity in both the stresses were associated with decreased carboxylation efficiency, but without affecting the internal concentration of carbon dioxide. The JIP-test parameters revealed changes in the energy flux processes demonstrating that in terms of flooding the rootstock GxN-9 the rate of photosynthetic performance significantly decreases, resulting in a considerable decrease in net assimilation...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Abiotic stress; Chlorophyll a fluorescence; Gas exchange; JIP-test; Prunus dulcis Mill. × Prunus persica L. Bastsch.
Ano: 2011
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202011000300007

Partitioning of water soluble carbohydrates in vegetative tissues of Lolium multiflorum Lam. ssp. italicum cv. Lema
Provedor de dados: 61
Autores: Sandrin,Carla Zuliani; Domingos,Marisa; Figueiredo-Ribeiro,Rita de Cássia Leone.
In temperate grasses, fructans are the major storage polysaccharides, being accumulated mainly in mature leaf sheaths, and also in the roots. The partitioning of carbohydrates within different organs regulates plant growth and development. The aim of the present work was to analyze the partitioning of water soluble carbohydrates in five different parts (elongating leaf blades, expanded leaf blades, upper and lower segments of the stubble, and roots) of plants of L. multiflorum cv. Lema, in order to contribute to an understanding of soluble carbohydrates distribution in these plants. Soluble carbohydrates and total fructose were analyzed in plants cultivated during 4 months in a glasshouse, by colorimetric, TLC and HPAEC-PAD techniques. Results showed that...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Fructan; Grass; Italian ryegrass; Sugars.
Ano: 2006
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202006000200006

Evaluation of hydration indexes in kale leaves
Provedor de dados: 61
Autores: Calbo,Adonai G.; Ferreira,Marcos D.
Hydration indexes are practical variables for quantifying plant water stress and can be useful for agronomic purposes. Three adapted hydration indexes based on relative water content, volumetric hydration, and leaf turgor pressure were evaluated in kale (Brassica oleracea var. acephala) leaf segments. Relative water content and volumetric hydration were measured in leaf segments after a water infiltration procedure with the aim of filling its large intercellular volumes (@18%v/v). The infiltration was done using a hydrostatic weighing procedure and with the aid of vacuum to fully hydrate the leaf segments. These two relative indexes were proportional to the transpiration-induced leaf water loss. The third index, turgor pressure, was measured with a...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Brassica oleracea; Intercellular air volume; Volumetric hydration; Relative water content; Turgor pressure; Leaf volumetric elastic modules; Wiltmeter.
Ano: 2011
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202011000200006

Leaf heliotropism in Styrax camporum Pohl from the Brazilian cerrado: distinct gas exchange and leaf structure, but similar leaf temperature and water relations
Provedor de dados: 61
Autores: Habermann,Gustavo; Machado,Silvia R.; Guimarães,Vandeir F.; Rodrigues,João D.
Styrax camporum is a common shrub species from the cerrado regions of São Paulo State, Brazil. Although its leaves do not have a morphologically delimited pulvinus, the apical leaves are oriented parallel to the sun (paraheliotropic leaves), most notably around noon. Horizontal leaves at the base of shoots are oriented perpendicular to the sun's rays (diaheliotropic leaves). The ecophysiological significance of this is not fully understood. We investigated how paraheliotropism influences daily CO2 assimilation (A) and other gas exchange rates, water relations, leaf temperature (Tl), and how these relate to leaf structure as assessed by anatomical leaf descriptions. Paraheliotropic leaves had greater A and stomatal conductance (g s), which led to greater...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Brazilian savanna; Ecophysiology; Gas exchange; Leaf movements; Leaf temperature; Photosynthesis; Styracaceae.
Ano: 2008
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202008000100008

Lead uptake and tolerance of Ricinus communis L.
Provedor de dados: 61
Autores: Romeiro,Solange; Lagôa,Ana M.M.A.; Furlani,Pedro R.; Abreu,Cleide A. de; Abreu,Mônica F. de; Erismann,Norma M.
Phytoextraction is an important technique used for the decontamination of areas polluted by lead. Consequently, an understanding of the physiological responses to tolerance of tropical species subjected to increasing levels of contamination is fundamental before considering their use as phytoextractors in contaminated areas. The objective of this study was to assess the lead (Pb) uptake and the tolerance of Ricinus communis L. The plants were cultivated in nutrient solution in a greenhouse under controlled conditions. Lead was tested at concentrations of 0, 100, 200 and 400 µmol L-1. The experimental set-up was a block design, using a 4 x 1 factorial scheme, with three replicates. Biometric analyses, photosynthesis rates, and Pb content in the nutritive...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Castor bean; Heavy metal; Lead; Phytoremediation.
Ano: 2006
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202006000400006

Flowering and vegetative growth of olive tree submitted to pruning and paclobutrazol application
Provedor de dados: 61
Autores: Cruz,Maria C. M.; Oliveira,Adelson F.; Oliveira,Dili L.; V. Neto,João.
This work focuses on the evaluation of flowering and vegetative growth of olive tree submitted to pruning and paclobutrazol application under field conditions with low temperatures during the winter. Two-years-old olive plant variety Grappolo 575, were submitted to light pruning, removing apical dominance, before treatments application. The treatments were organized in a 4×2 factorial scheme, respective to four PBZ concentrations tested: 0, 200, 400 and 800 mg L-1 of PBZ and two plants groups, with and without pruning, in randomized block with four replications. Paclobutrazol concentrations tested did not affect the olive tree flowering. The plant vegetative growth was reduced until 60 days after paclobutrazol application. Pruning resulted in stimulation...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Floral induction; Growth regulators; Management; Olea europaea L.
Ano: 2011
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202011000200002

Salt-induced changes in antioxidative enzyme activities in root tissues do not account for the differential salt tolerance of two cowpea cultivars
Provedor de dados: 61
Autores: Maia,Josemir M; Voigt,Eduardo L; Macêdo,Cristiane E. C; Ferreira-Silva,Sérgio L; Silveira,Joaquim A. G.
The salt stress effect in root growth and antioxidative response were investigated in two cowpea cultivars which differ in salt tolerance in terms of plant growth and leaf oxidative response. Four-day-old seedlings (establishment stage) were exposed to 100 mM NaCl for two days. The roots of the two cultivars presented distinct response in terms of salt-induced changes in elongation and dry weight. Root dry weight was only decreased in Pérola (sensitive) cultivar while root elongation was mainly hampered in Pitiúba (tolerant). Root relative water content remained unchanged under salinity, but root Na+ content achieved toxic levels as revealed by the K+/Na+ ratio in both cultivars. Then, root growth inhibition might be due to ionic toxicity rather than by...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Antioxidative enzymes; Oxidative stress; Root growth inhibition; Salt stress; Vigna unguiculata.
Ano: 2010
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202010000200005

Alterations in leaf anatomy and physiology caused by the red mite (Oligonychus ilicis) in plants of Coffea arabica
Provedor de dados: 61
Autores: Fahl,Joel I.; Queiroz-Voltan,Rachel B.; Carelli,Maria Luiza C.; Schiavinato,Marlene A.; Prado,Ana K. S.; Souza,Júlio C.
Three degrees of red mite infestation (Oligonychus ilicis McGregor) (Acari: Tetranychidae) were evaluated with regard to leaf anatomy, photosynthetic gas exchange and leaf ethylene production, in a commercial crop of approximately 12-year-old trees of Coffea arabica 'Catuaí Vermelho'. As a complementary study, foliar anatomy was also evaluated in a recuperated crop of C. arabica 'Mundo Novo' that had presented a high degree of red mite infestation during the dry period of the prior growing season. The red mite-infested leaves were bronze-coloured, with intensity proportional to the degree of internal damage. On feeding, the red mite introduces its stylet in the adaxial epidermis and, as a result, chloroplasts are destroyed in the feeding area. The number...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Coffee; Ethylene; Leaf structure damage; Photosynthetic gas exchange.
Ano: 2007
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202007000100007

Effect of plant growth regulators on oil yield and biodiesel production of safflower (Carthamus tinctorius L.)
Provedor de dados: 61
Autores: Ullah,Faizan; Bano,Asghari.
The aim of the present investigation was to determine the effect of plant growth regulators viz., kinetin, chlorocholine chloride (CCC) and salicylic acid (SA) on achene yield and oil quality of safflower (Carthamus tinctorius L.) cv. Thori pertaining to biodiesel production. The growth regulators were applied at 10-5M as foliar spray during flowering (140 days after sowing). Kinetin was highly effective in increasing achene yield, 100 achene weight and oil refractive index. Maximum achene oil content was found in CCC treatment. Kinetin and CCC significantly decreased oil acid value, free fatty acid content (% oleic acid) and specific gravity but increased oil pH. Kinetin was highly effective in increasing oleic acid (C18:1) but decreased the content of...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Biodiesel; Plant growth regulators; Safflower; Oil quality.
Ano: 2011
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202011000100005

Effect of Methyl Jasmonate on antioxidative enzyme activities and on the contents of ROS and H2O2 in Ricinus communis leaves
Provedor de dados: 61
Autores: Soares,Alexandra Martins dos Santos; Souza,Thiago Freitas de; Jacinto,Tânia; Machado,Olga Lima Tavares.
Jasmonates are a class of plant hormones that mediate various aspects in gene and metabolic regulation, defense, stress responses, reproduction and, possibly, communication. Oxidative stress stimulates synthesis of antioxidant metabolites and enhances antioxidant enzyme activities that could protect plant tissues. The aim of this study was to verify the effects of methyl jasmonate (JAME) treatment on the reactive oxygen species (ROS) and on the activities of H2O2 scavenging enzymes, such as superoxide dismutase (SOD; EC 1.15.1.1), catalase (CAT; EC 1.11.1.6), ascorbate peroxidase (APX EC; 1.11.1.1), and guaiacol peroxidase (GPX; EC 1.11.1.7) in Ricinus communis leaves. The activity of CAT and GPX was transient while SOD activity decreased and APX increased...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Methyl jasmonate; Oxidative stress; Antioxidant enzymatic defenses; Catalase; Superoxide dismutase; Peroxidase; Ricinus comunnis; Signal transduction.
Ano: 2010
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202010000300001

Growth, photosynthesis, nodule nitrogen and carbon fixation in the chickpea cultivars under salt stress
Provedor de dados: 61
Autores: Garg,Neera; Singla,Ranju.
Four cultivars of chickpea, two of them of Mediterranean origin (kabuli), CSG 9651, BG 267 and two Indian (desi) types, CSG 8962, DCP 92-3, differing in their salt sensitivities were identified after screening ten genotypes in saline soils. The cultivars CSG 9651 and CSG 8962 were salt tolerant while BG 267 and DCP 92-3 were salt sensitive, respectively. The seeds of different cultivars were inoculated with Mesorhizobium ciceri, strain F: 75 and the plants were grown in the greenhouse. After the establishment of symbiosis, 15-day-old seedlings were administered doses of saline at varying concentrations (0, 4, 6, 8 dSm-1 NaCl, Na2SO4, CaCl2). Plants were harvested at 40, 70 and 100 days after sowing, for analyses. The main aim was to compare the relative...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Chlorophyll pigments; Nitrogenase activity; Nodule; PEPCase; Rubisco.
Ano: 2004
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202004000300003

Water relations and organic solutes production in four umbu tree (Spondias tuberosa) genotypes under intermittent drought
Provedor de dados: 61
Autores: Silva,Elizamar C.; Nogueira,Rejane J. M. C.; Vale,Fernando H. A.; Melo,Natoniel F. de; Araújo,Francisco P. de.
In order to evaluate changes in leaf water potential (ψw) and solute accumulation induced by intermittent drought, an research was performed under greenhouse conditions using four umbu tree genotypes (GBU 44, GBU 48, GBU 50 and GBU 68) and two water treatments (control and stressed by withholding water), with four replicates. The ψw was measured in four-hour intervals during a 24-hour period at the first stomatal closure and at the end of the experimental period. Carbohydrates, amino acids, protein and proline contents were also evaluated in leaves and roots. Significant differences were found in most of the studied parameters. The lower ψw hour was between 800 h and 1200 h. GBU 50 reduced significantly ψw in stressed plants at 800 h, while control plants...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Carbohydrates; Proline; Spondias tuberosa; Water potential.
Ano: 2009
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202009000100006

Physiological response of oil palm interspecific hybrids (Elaeis oleifera H.B.K. Cortes versus Elaeis guineensis Jacq.) to water deficit
Provedor de dados: 61
Autores: Méndez,Yurany Dayanna Rivera; Chacón,Leonardo Moreno; Bayona,Cristihian Jarry; Romero,Hernán Mauricio.
Water supply is the main yield-limiting abiotic factor of oil palm in Colombia. To determine the effect of water deficit on the physiology of oil palm and to assess the tolerance degree to this condition, interspecific Elaeis oleifera versus Elaeis guineensis 'U1273', 'U1859', 'U1914', and 'U1937' hybrids were planted for 60 days in soil with different water potentials (-0.042, -0.5, -1.0, and -2.0 MPa) in a complete randomized factorial design with three replications. The water potential, osmotic adjustment molecules (total and reducing sugar content), gas exchange (photosynthesis rate, stomatal conductance, water use efficiency, and leaf respiration), and vegetative growth (height, bulb diameter, leaf area, number of leaves, total dry matter, and...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Ecophysiology; Growth; Stress; Tolerance; Water potential.
Ano: 2012
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202012000400006

CO2 assimilation, photosynthetic light response curves, and water relations of 'Pêra' sweet orange plants infected with Xylella fastidiosa
Provedor de dados: 61
Autores: Habermann,Gustavo; Machado,Eduardo Caruso; Rodrigues,João Domingos; Medina,Camilo Lázaro.
Plants with citrus variegated chlorosis (CVC), a disease caused by the xylem-limited bacteria Xylella fastidiosa, have leaves with water deficiency symptoms and are associated with decreases on the net photosynthesis and transpiration rates. Using healthy and CVC-affected 'Pêra' sweet orange plants on 'Rangpur' lime rootstock, the leaf gas exchange variables were measured with an open-gas portable photosynthesis system. All plants were watered and the leaf water potential (Yw) was measured by isopiestic thermocouple psychrometric technique. The net photosynthesis (A) vs. internal leaf CO2 concentration (A/Ci curves) was analyzed. The relative effect of stomatal resistance on photosynthesis (S%) and the estimation of carboxylation efficiency were...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: A/Ci curves; Citrus variegated chlorosis; Citrus sinensis L. Osbeck; Photosynthetic photon flux density; Photosynthetic metabolism; Stomata.
Ano: 2003
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202003000200003

Effects of Zn and Cd accumulation on structural and physiological characteristics of barley plants
Provedor de dados: 61
Autores: Sridhar,Balaji B. Maruthi; Han,Fengxiang X.; Diehl,Susan V.; Monts,David L.; Su,Yi.
The objectives of this study were to identify the structural changes caused by Zn and Cd accumulation in shoots and roots of barley (Hordeum vulgare) plants; and to correlate metal accumulation with anatomical, physiological and morphological changes. Potted plants were exposed to metal treatments of Zn and Cd for 19 and 16 d respectively. Leaves, stems and roots were harvested to identify structural changes and analyze metal accumulation. Barley effectively accumulated Zn (up to 11283 mg kg-1) and Cd (up to 584 mg kg-1) in the shoots. Microscopic structural changes, such as a decrease in intercellular spaces, breakdown of vascular bundles, and shrinkage of palisade and epidermal cells, occurred in leaves, stems and roots of plants treated with high...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Anatomy; Cadmium; Hordeum vulgare; Microscopy; Phytoremediation; Zinc.
Ano: 2007
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202007000100002

Adaptability and leaf anatomical features in oil palm seedlings produced by embryo rescue and pre-germinated seeds
Provedor de dados: 61
Autores: Luis,Zanderluce G.; Bezerra,Kadja Milena G.; Scherwinski-Pereira,Jonny Everson.
Changes in the leaf structure of plants grown in different conditions have been reported, such as increase in size and density of stomata and reduction in stomatal control, amount of epicuticular wax, and mesophyll thickness, with a high diversity of intercellular spaces. However, these changes are highly variable depending on the physiological and morphological characteristics of each species. The objective of this work was to analyze the adaptability and anatomical plasticity of oil palm seedlings produced after embryo rescue and pre-germinated seeds. Expanded leaves were prepared for evaluation of morphometric data and anatomical structures. It was verified that the environmental conditions in vitro negatively influenced the stomata density, epidermal...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Elaeis guineensis; Arecaceae; Germination; Embryo culture; Acclimatization; Plantlets metabolism.
Ano: 2010
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202010000300008

Induction and differentiation of reproductive buds in Coffea arabica L.
Provedor de dados: 61
Autores: Majerowicz,Nidia; Söndahl,Maro R.
The induction and differentiation phases of reproductive buds of Coffea arabica L. have not received much attention. In the present paper, axillary buds from five plagiotropic branches that developed in the same growing season without fruits (1st crop branches), and from green segments of five recently grown plagiotropic branches with fruits (2nd crop branches), were collected every two weeks during successive inductive months of the year. This study was carried out with adult arabica trees, Catuaí Vermelho cv. IAC 81, cultivated under normal farming conditions in the region of Campinas, SP, Brazil (22º54' Lat. S). Slides of longitudinal-axial sections of 10-12 mum thickness were mounted for the characterization and quantification of histological stages of...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Arabica coffee; Floral differentiation; Floral induction; Flower buds; Histological differentiation; Reproductive development.
Ano: 2005
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202005000200008

Comparative stomatal conductance and chlorophyll a fluorescence in leaves vs. fruits of the cerrado legume tree, Dalbergia miscolobium
Provedor de dados: 61
Autores: Lemos Filho,José Pires de; Isaias,Rosy Mary dos Santos.
The aim of this study was to compare water vapor conductance and chlorophyll a fluorescence between leaflets and fruits of Dalbergia miscolobium, the Jacaranda tree. The frequency of stomata on the leaflets was 20 times higher than that observed on the fruits, and this was related with the lower conductance of the fruits in comparison with the leaflets. The potential quantum yield of PSII (Fv /Fmax) was significantly lower in fruits than in leaflets. The Fv /Fmax values for leaflets increased to over 0.8 during the afternoon, indicating the occurrence of dynamic photoinhibition. In contrast, Fv /Fmax values for fruits remained low even at early morning, indicating the occurrence of chronic photoinhibition. The maximum values of effective quantum yield...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Jacaranda tree; Stomata; Quantum efficiency of PSII; Water vapor conductance.
Ano: 2004
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202004000200004

Plant- and stand-level variation in biophysical and physiological traits along tree density gradients in the Cerrado
Provedor de dados: 61
Autores: Scholz,Fabian G.; Bucci,Sandra J.; Goldstein,Guillermo; Meinzer,Frederick C.; Franco,Augusto C.; Salazar,Ana.
The objective of this study was to characterize and understand morphological and physiological variation in traits related to water economy, at the plant and stand level, along a gradient of tree density in a Neotropical savanna (Cerrado). Cerrado plots subjected to long-term fertilization and gallery forests were also included in the analysis to expand the axes of ecosystem variation. Consistent changes in stand level biophysical traits observed along the gradient of increasing tree density included a decrease in weighted-average wood density, and increases in leaf surface area per plant, leaf specific hydraulic conductivity, specific leaf area and stomatal conductance. A conceptual model of biophysical, morphological and physiological trait interactions...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Gallery forest; Hydraulic architecture; Nutrients; Savannas; Specific leaf area; Wood density.
Ano: 2008
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202008000300006

Spatial and temporal variation of the nutrients in the sediment and leaves of two Brazilian mangrove species and their role in the retention of environmental heavy metals
Provedor de dados: 61
Autores: Bernini,Elaine; Silva,Maria A. B. da; Carmo,Tania M. S. do; Cuzzuol,Geraldo R. F.
Spatial and temporal variation of the nutrient concentrations in leaves and sediment between the roots of Laguncularia racemosa (L.) Gaertn. f and Rhizophora mangle L. was analyzed in the mangrove forest of the estuary of São Mateus River, Espírito Santo, Brazil. In leaves, the nutrients followed the sequence: N&gt; Ca&gt; K&gt; Mg&gt; S&gt; P&gt; Fe&gt; Mn&gt; Zn&gt; Cu, and there were significant differences between species and sites studied. In general, the levels of K were higher in the dry season compared to the rainy season for both species analyzed while Ca and Cu showed higher concentrations in the rainy season for Laguncularia racemosa. In the sediment, the nutrients followed the sequence: Mg&gt; Ca&gt; Fe&gt; K&gt; Mn&gt; P&gt; Zn&gt; Cu, in...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Concentration factor; Macronutrients; Micronutrients; Metals.
Ano: 2010
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202010000300005

I. Heat stress in Triticum: kinetics of Ca and Mg accumulation
Provedor de dados: 61
Autores: Dias,Ana S.; Lidon,Fernando C.; Ramalho,José C.
In heat stressed genotypes of Triticum aestivum L. (Sever and Golia) and Triticum turgidum subsp. durum (Acalou and TE 9306), chosen according to its genetic background diversity, Ca and Mg accumulations were correlated with its photosynthetic performance. It was found that with high temperatures the concentrations of Ca increased in the shoots, whereas the accumulation of Mg augmented only in bread wheat genotypes. Under heat stress, the pattern of electrolytes release in Golia and Acalou remained similar, but the extrusion rates became higher in Sever. During grain filling, the levels of total chlorophylls decreased in the heat stressed genotypes (excepting in Sever). In all the Triticum genotypes, stomatal conductance and the net carboxilation rate...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Triticum aestivum L.; Triticum turgidum subsp. durum; Net photosynthesis; Nutrients uptake and translocation; Stomatal conductance.
Ano: 2009
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202009000200005

Effect of maleic hydrazide on respiratory parameters of stored onion bulbs (Allium cepa L.)
Provedor de dados: 61
Autores: Benkeblia,Noureddine.
The respiration rate (RR) (CO2 production), activation energy (Ea) and Q10 of maleic hydrazide-treated onion bulbs (Allium cepa, cv. Rouge Amposta) at 20.10-6 mol.L-1 (MH1) and 45.10-6 mol.L-1 (MH2) were measured at 4, 10 and 20ºC. Immediately after treatment, the Q10 of MH-treated and control bulbs were not significantly different. After 8 weeks of storage, Q10 of control and both MH-treated bulbs increased and ranged from 2.34 and 2.89. Respiration rate of onions increased during storage, and after 24 weeks, RR values of control, MH1 and MH2 were 0.43, 0.32 and 0.26 mmol CO2.kg-1.h-1 at 20ºC respectively; and 0.26, 0.20 and 0.17 mmol CO2.kg-1.h-1 at 10ºC respectively. At 4ºC, no significant difference was observed between control and MH-treated bulbs....
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Activation energy; MH; Onion; Q10; Respiration rate; Sprouting; Storage.
Ano: 2004
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202004000100007

Carbon isotope composition and leaf anatomy as a tool to characterize the photosynthetic mechanism of Artemisia annua L.
Provedor de dados: 61
Autores: Marchese,José Abramo; Broetto,Fernando; Ming,Lin Chau; Ducatti,Carlos; Rodella,Roberto Antonio; Ventrella,Marília Contin; Gomes,Greice Daiane Rodrigues; Franceschi,Lúcia de.
Leaves of Artemisia annua L. are a plentiful source of artemisinin, a drug with proven effectiveness against malaria. The aim of this study was to classify the photosynthetic mechanism of A. annua through studies of the carbon isotope composition (delta 13C) and the leaf anatomy. A. annua presented a delta 13C value of - 31.76 ± 0.07, which characterizes the plants as a typical species of the C3 photosynthethic mechanism, considering that the average delta 13C values for C3 and C4 species are -28 and -14, respectively. The leaf anatomy studies were consistent with the delta 13C results, where, in spite of the existence of parenchymatic cells forming a sheath surrounding the vascular tissue, the cells do not contain chloroplasts or starch. This...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: C3 and C4 plants; Isotope discrimination; Kranz anatomy; Photosynthesis.
Ano: 2005
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202005000100016

Physiological and cytological aspects of Inga vera subsp. affinis embryos during storage
Provedor de dados: 61
Autores: Faria,José M.R.; Davide,Lisete C.; Silva,Edvaldo A. A. da; Davide,Antonio C.; Pereira,Roselaine C.; van Lammeren,André A.M.; Hilhorst,Henk W.M.
The remarkably short storability of recalcitrant seeds has prevented their inclusion in programs of ex situ conservation. The causes of their desiccation sensitivity and rapid decline in viability during storage are not fully elucidated yet. In this study the highly recalcitrant, fully viable embryos of the tree species Inga vera subsp. affinis were stored under various conditions and analyzed physiologically and cytologically at intervals, in order to obtain more insights in their loss of viability during storage. Embryos stored fully hydrated at 5ºC fully lost viability in 18 d. Sealed storage of partially dehydrated embryos slightly prolonged their viability, with 95% germination being attained after 14 d of storage. However, after 30 d of storage,...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Abscisic acid; Polyethylene glycol; Recalcitrant seeds; Seed conservation.
Ano: 2006
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202006000400008

Water relations and hydraulic architecture in Cerrado trees: adjustments to seasonal changes in water availability and evaporative demand
Provedor de dados: 61
Autores: Bucci,Sandra J.; Scholz,Fabian G.; Goldstein,Guillermo; Meinzer,Frederick C.; Franco,Augusto C.; Zhang,Yongjiang; Hao,Guang-You.
We determined adjustments in physiology and morphology that allow Neotropical savanna trees from central Brazil (Cerrado) to avoid water deficits and to maintain a nearly constant internal water balance despite seasonal changes in precipitation and air saturation deficit (D). Precipitation in the study area is highly seasonal with about five nearly rainless months during which D is two fold higher compared to wet season values. As a consequence of the seasonal fluctuations in rainfall and D, soil water potential changes substantially in the upper 100 cm of soil, but remains nearly constant below 2 m depth. Hydraulic architecture and water relations traits of Cerrado trees adjusted during the dry season to prevent increasing water deficits and insure...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Isohydric behavior; Hydraulic conductivity; Soil water potential and water content; Savanna; Stomatal conductance; Transpiration.
Ano: 2008
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202008000300007

Identification of aluminum resistant Andean common bean (Phaseolus vulgaris L.) genotypes
Provedor de dados: 61
Autores: Blair,Matthew W.; López-Marín,Hernán D.; Rao,Idupulapati M.
Aluminum (Al) toxicity is the principal abiotic constraint in acid soils of the tropics. Common bean, meanwhile, is for the most part very sensitive to this stress although certain genotypes within the species show some level of resistance, justifying screening of germplasm from both the Andean and Mesoamerican genepools to identify better performing sources. The objective of this study was to evaluate 36 genotypes of common bean under hydroponic conditions to identify root morphological traits that could be associated with Al resistance. A total of five root traits (elongation rate of the primary root, total root length, root biomass, average root diameter and specific root length) were measured using a simple nutrient solution with or without Al (20 µM)...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Abiotic stress; Acid soils; Aluminum resistance; Andean gene pool; Common bean; Root architecture.
Ano: 2009
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202009000400005

Physiological disturbances promoted by ozone in five cultivars of Phaseolus vulgaris L.
Provedor de dados: 61
Autores: Clebsch,Cláudia C.; Divan Junior,Armando M.; Oliveira,Paulo L.; Nicolau,Márcio.
Bean seedlings of Fepagro 26, Guapo Brilhante, Iraí, Macotaço and US Pinto 111 cultivars were submitted to treatments with or without addition of ozone to the ambient air, in order to evaluate the effects of exposure on photosynthesis, relative electrolyte leakage, foliar abscission and biomass of the seedlings. Exposure to ozone caused significant decreases in the net assimilation of all cultivars except Iraí. It also caused a significant increase in electrolyte leakage from the Pinto cultivar, but only when AOT40 was the highest. It also produced significant anticipation in the time of foliar abscission in the Pinto, Fepagro and Guapo cultivars. The variability observed in the biomass measurements reflected the limitations to perform long-term...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Photosynthesis; Relative electrolyte leakage; Foliar abscission; Biomass.
Ano: 2009
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202009000400008

Changes induced by Cu2+ and Cr6+ metal stress in polyamines, auxins, abscisic acid titers and antioxidative enzymes activities of radish seedlings
Provedor de dados: 61
Autores: Choudhary,Sikander P.; Bhardwaj,Renu; Gupta,Bishan D.; Dutt,Prabhu; Gupta,Rajinder K.; Kanwar,Mukesh; Dutt,Pitamber.
The present study determined the effects of copper and chromium metals on the endogenous titers of polyamines, auxins, abscisic acid and antioxidative enzyme activities in Raphanus sativus L. cv. Pusa chetki seedlings. Among polyamines, putrescine and spermidine contents were enhanced by Cu2+ metal to 62.44 and 402.8 µg g-1 f.w. respectively over control. Spermine which was not observed in control was recorded in highest concentration (1287.9 µg g-1 f.w.) in Cu2+ metal stressed seedlings. On the other hand Cr6+ metal treated seedlings showed reduced contents of putrescine (1.43 µg g-1 f.w.), cadaverine (0.09 µg g-1 f.w.), spermidine (277.99 µg g-1 f.w.) and spermine (2.29 µg g-1 f.w.) when compared to control and Cu2+ metal treated seedlings. Significant...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Catalase; Chromium; Copper; Guaiacol peroxidase; Polyamines (PAs); Superoxide dismutase.
Ano: 2010
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202010000400006

Stimulation of antioxidant system and lipid peroxidation by abiotic stresses in leaves of Momordica charantia
Provedor de dados: 61
Autores: Agarwal,Sheela; Shaheen,Robina.
The purpose of the present work was to evaluate both the antioxidant response system and oxidative stress in leaves from bitter gourd (Momordica charantia L) subjected to NaCl, UV-B and water stresses at three different stages of plant growth: pre-flowering, flowering and post-flowering. Except for peroxidase (POX), all enzyme activities including superoxide dismutase (SOD), catalase (CAT), polyphenol oxidase (PPO), glutathione reductase (GR), as well as concentrations of ascorbate (ASA), hydrogen peroxide (H2O2) and thiobarbituric acid reactive substances (TBARS) exhibited maximum values at the flowering stage under all three stresses. All the enzyme activities, SOD, CAT, POX, PPO, GR and the concentrations of ASA, H2O2 and TBARS were elevated under NaCl...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Antioxidative enzymes; Environmental stresses; H2O2; Ion concentration; Thiobarbituric acid-reactive substances.
Ano: 2007
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202007000200007

Ecophysiology of the cacao tree
Provedor de dados: 61
Autores: Almeida,Alex-Alan F. de; Valle,Raúl R.
Cacao, one of the world's most important perennial crops, is almost exclusively explored for chocolate manufacturing. Most cacao varieties belong to three groups: Criollo, Forastero and Trinitario that vary according to morphology, genetic and geographical origins. It is cropped under the shade of forest trees or as a monocrop without shade. Seedlings initially show an orthotropic growth with leaf emission relatively independent of climate. The maturity phase begins with the emission of plagiotropic branches that form the tree crown. At this stage environmental factors exert a large influence on plant development. Growth and development of cacao are highly dependent on temperature, which mainly affects vegetative growth, flowering and fruit development....
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Root growth; Flowering; Pod set; Flushing; Mineral nutrition.
Ano: 2007
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202007000400011

Evaluation of physiological traits in upland rice for adaptation to no-tillage system
Provedor de dados: 61
Autores: Heinemann,Alexandre B.; Stone,Luís Fernando; Fageria,Nand K.; Castro,Lucas M. de.
In the cerrado region of Brazil, no-tillage is an alternative management practice to conserve soil and reduce cost of crop production. However, many studies have been showed that there is a decrease in the yield when upland rice is cropped in this system. Therefore, there is a need that new breeding initiatives introgress favorable traits into upland rice for no-tillage adaptation. Key traits include faster emergence, ability to germinate when deep seeded, faster root development, and early canopy closure during the vegetative stages. All those traits can be summarized as "early vigor". So, the objective of this study was to evaluate physiological traits of four contrasting parental upland rice cultivars to verify their adaptation to no-tillage system. A...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Leaf area; Leaf expansion; Oryza sativa L; Shoot dry weight.
Ano: 2009
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202009000200004

Editorial: greetings from the new Editor-in-Chief - Celebrating the 20th anniversary of Brazilian Journal of Plant Physiology
Provedor de dados: 61
Autores: Façanha,Arnoldo Rocha.
Tipo: Info:eu-repo/semantics/article
Ano: 2009
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202009000100001

Relationship between gibberellic acid and growth parameters in developing seed and pod of pigeon pea
Provedor de dados: 61
Autores: Chudasama,Rita S.; Thaker,Vrinda S.
Changes in endogenous gibberellic acid (GA) levels were determined in developing seeds and pods of pigeon pea (Cajanus cajan). Antibodies against GA3 were raised in rabbits and indirect ELISA developed to estimate GA level. Two varieties, black seeded variety (V1) and B.D.N2 (V2), were selected on the basis of their seed index value. The pod length and number of seeds per pod were significantly different for the two varieties. Dry weight, water content (WC), rate of water accumulation, rate of dry matter accumulation (DMA), and GA content in pod and seed were all larger in V1 than in V2. In both varieties, higher GA content was observed during cell elongation and DMA phases, respective to their varietal differences in growth traits. Relationships between...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Cajanus cajan; Dry matter accumulation; Endogenous gibberellic acid; Seed development; Water content.
Ano: 2007
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202007000100005

cDNA-AFLP analysis of Psidium guajava L. cultivars under water stress and mechanical injury: methodological implications
Provedor de dados: 61
Autores: Furlan,Cláudia Maria; Zanotta,Samantha; Salatino,Antonio.
Studies involving amplified fragment length polymorphism (cDNA-AFLP) have often used polyacrylamide gels with radiolabeled primers in order to establish best primer combinations, to analyze, and to recover transcript-derived fragments. Use of automatic sequencer to establish best primer combinations is convenient, because it saves time, reduces costs and risks of contamination with radioactive material and acrylamide, and allows objective band-matching and more precise evaluation of transcript-derived fragments intensities. This study aimed at examining the gene expression of commercial cultivars of P. guajava subjected to water and mechanical injury stresses, combining analyses by automatic sequencer and fluorescent kits for polyacrylamide gel...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Automatic sequencer; Gene expression; Mechanical injury; Water stress.
Ano: 2012
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202012000100005

Impact of saline water stress on nutrient uptake and growth of cowpea
Provedor de dados: 61
Autores: Patel,Prakash R.; Kajal,Sushil S.; Patel,Vinay R.; Patel,Vimal J.; Khristi,Sunil M.
Soil salinity is a major limitation to crops production in many areas of the world. The present study reports the impact of salt stress on seeds germination, plant growth parameters and leaf ions accumulation in three cowpea Vigna unguiculata (L.) Walp Indian cultivars: Akshay102, Gomti vu-89 and Pusa Falguni. The electrical conductivity (EC) of the soil was 0.75 dS m−1 and the NaCl treatments increased it to 2, 4, 6, 8 and 10 dS m−1. Germination percentage was recorded 10 days after sowing, while shoot and root dry weights were measured in 45 days old plants. Leaf ion concentrations for Na+, K+, Ca2+, Cl− and proline content were determined. The results showed that the germination percentage of seeds was highly affected by salinity in all cultivars in all...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Salt stress; Germination; Proline; Potassium/sodium ratio.
Ano: 2010
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202010000100005

Responses of the maize plant to chromium stress with reference to antioxidation activity
Provedor de dados: 61
Autores: Maiti,Saborni; Ghosh,Nirmalia; Mandal,Chiranjib; Das,Kingsuk; Dey,Narottam; Adak,Malay Kumar.
Two maize varieties, viz. Sartaj and Deccan, have been evaluated according to their responses to chromium (Cr) in terms of specific physiological and biochemical attributes. During the exposure to Cr concentration (0, 50, 100, 200 and 300 µM) of potassium dichromate (K2Cr2O7) for seven days, significant changes of oxidative stress in terms of lipid peroxidation and protein oxidation were recorded along with other antioxidative pathways. It is revealed that irrespective of varieties, Sartaj was more prone to oxidative stress since the amount of superoxide due to Cr exposure was found to be significant, unlike the second variety, Deccan. In addition, for Sartaj the activity of NAD(P)H oxidase recorded a significant linear increase in a dose response...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Antioxidative enzymes; MDA; Protein oxidation; ROS.
Ano: 2012
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202012000300007

Physiological and biochemical changes occurring in dwarf-cashew seedlings subjected to salt stress
Provedor de dados: 61
Autores: Abreu,Carlos E.B. de; Prisco,José T.; Nogueira,Ana R.C.; Bezerra,Marlos A.; Lacerda,Claudivan F. de; Gomes-Filho,Enéas.
The effects of salt stress on some physiological and biochemical traits were evaluated in dwarf-cashew seedlings at the same developmental stage. Seeds were sown in trays containing vermiculite moistened with distilled water or with NaCl solutions having different electrical conductivities: 0.7, 1.8, 6.0, 9.8, 13.4, 17.4 and 20.6 dS m-1. Salinity delayed and inhibited seedling growth and development, particularly in the shoot. Concentrations of Na+ and Cl-, but not of K+, increased with increasing stress severity. With the exception of proline, concentration of organic solutes was only marginally affected by salt stress. Catalase activity in leaves increased slightly as a result of salt stress, whereas guaiacol peroxidase activity was induced only under...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Anacardium occidentale; Antioxidant enzymes; Lipid peroxidation; Oxidative stress; Protein pattern; Salt stress.
Ano: 2008
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202008000200003

Ecophysiology of papaya: a review
Provedor de dados: 61
Autores: Campostrini,Eliemar; Glenn,David M.
Papaya (Carica papaya L.) is a principal horticultural crop of tropical and subtropical regions. Knowledge of how papaya responds to environmental factors provides a scientific basis for the development of management strategies to optimize fruit yield and quality. A better understanding of genotypic responses to specific environmental factors will contribute to efficient agricultural zoning and papaya breeding programs. The objective of this review is to present current research knowledge related to the effect of environmental factors and their interaction with the photosynthetic process and whole-plant physiology. This review demonstrates that environmental factors such as light, wind, soil chemical and physical characteristics, temperature, soil water,...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Carica papaya; Environmental factors; Photosynthesis; Water relations; Water-use efficiency.
Ano: 2007
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202007000400010

Development of the nodulated soybean plant after flooding of the root system with different sources of nitrogen
Provedor de dados: 61
Autores: Thomas,André Luís; Sodek,Ladaslav.
Flooding leads to hypoxia, a stress to which symbiotic N2 fixation is especially sensitive. The response of fully nodulated soybean plants to a 21-day period of flooding was studied by measurements of growth parameters and xylem transport of organic nitrogenous components to the shoot, in the presence and absence of NO3- and NH4+ in the medium. Flooding was found to seriously impair N2 fixation, irrespective of the N source, as indicated by strongly reduced xylem ureide levels. In the absence of a source of N, growth was strongly reduced during flooding while accumulation of N in the shoot was virtually abolished. Flooding in the presence of 5 mM NO3- or NH4+ led to the accumulation of total N in the shoot but only NO3- promoted increases in total dry...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Glycine max; Anaerobiosis; Oxygen deficiency.
Ano: 2005
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202005000300003

Sensibilidade estomática ao ABA em função do pH e de níveis de Ca2+, NO3- e PO4(3-) na seiva do xilema
Provedor de dados: 61
Autores: Oliveira,Maria Neudes Sousa de; Oliva,Marco Antonio; Martínez,Carlos Alberto; Mercier,Helenice; Silva,Marco Aurélio Pedron e.
A hipótese de que a sensibilidade estomática ao ácido abscísico (ABA) possa ser influenciada pelas características da seiva xilemática, como pH e concentração de Ca2+, NO3- e PO4(3-), foi testada em plantas de Lycopersicon esculentum L. var. Santa Clara submetidas a estresse hídrico induzido pela adição de PEG 6000 à solução nutritiva. Estimou-se a sensibilidade estomática ao ABA pela relação transpiração/ABA xilemático. Plantas intactas foram submetidas a estresse hídrico rápido e lento e determinaram-se as variações de pH e as concentrações de Ca2+, NO3- e PO4(3-) na seiva do xilema Também se estudaram os efeitos de diversas concentrações de Ca2+, NO3- e PO4(3-) sobre a transpiração em folhas destacadas imersas em seiva artificial contendo ABA exógeno....
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Lycopersicon esculentum L.; Estresse hídrico; Seiva xilemática; Transpiração.
Ano: 2002
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202002000200006

Germination of dormant seeds of Stylosanthes humilis as promoted by ethylene accumulation in closed environments
Provedor de dados: 61
Autores: Ribeiro,Dimas Mendes; Barros,Raimundo Santos.
Germination of scarified dormant seeds of Townsville stylo (Stylosanthes humilis) is very low in Petri dishes, but may be appreciable in sealed Erlenmeyer flasks if ethylene accumulates in their atmospheres. When ethylene in the flask atmosphere was fixed by a mercuric perchlorate solution, emanation of the gaseous regulator and germination of dormant seeds were drastically decreased. On the other hand, ethylene produced by dormant seeds and accumulated in the flask atmosphere led to a further enhancement of ethylene accumulation and a corresponding increased seed germination. Germination of both dormant and non-dormant seeds did not occur when ethylene biosynthesis was completely blocked.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Townsville stylo; Closed environments; Dormancy; Ethylene; Germination; Seeds.
Ano: 2004
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202004000200003

Effectivity of anti-oxidative enzymatic system on diminishing the oxidative stress induced by aluminium in chickpea (Cicer arietinum L.) seedlings
Provedor de dados: 61
Autores: Singh,Sushant; Verma,Anil; Dubey,Vikash Kumar.
We explore physiological and biochemical response under increasing aluminium stress at different time interval in chickpea seedlings (Cicer arietinum L.). Germination percentage and root length were found to be highly reduced under increasing metal stress. Aluminium induced oxidative stress and led to fluctuations in antioxidative activity responses. Roots showed higher antioxidative activity compared to shoots. Low concentration of aluminium after a brief treatment induced higher superoxide dismutase (SOD; EC 1.15.1.1), ascorbate peroxidase (APX; EC 1.11.1.11) and guaiacol peroxidase (GPX; EC 1.11.1.7) activity whereas longer duration of treatment led to decrease in these activities. Malondialdehyde concentration indicated higher oxidative damage in roots...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Ascorbate peroxidases; Heavy metal; Malondialdehyde; Superoxide dismutase; Oxidative stress.
Ano: 2012
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202012000100007

Moderate warm temperature improves shoot growth, affects carbohydrate status and stimulates photosynthesis of sweet orange plants
Provedor de dados: 61
Autores: Ribeiro,Rafael Vasconcelos; Machado,Eduardo Caruso; Espinoza-Núñez,Erick; Ramos,Rômulo Augusto; Machado,Daniela Favero São Pedro.
Citrus plants were grown under two thermal conditions for evaluating carbon metabolism acclimation to moderate warm temperature (30/20ºC, day/night), and its likely impact on plant growth. As reference, plants were grown at 25/20ºC, in which they were subjected to optimum temperature for photosynthesis during the diurnal period (25ºC). Higher photosynthetic rates were found at 30/20ºC as compared to 25/20ºC in both mature and young leaves, being this response associated with higher stomatal conductance. After 30 days of thermal treatment, plants grown at 30/20ºC presented higher shoot growth as compared to those at 25/20ºC. The carbohydrate concentration decreased in stem and root tissues, while it increased in leaf tissues under moderate warm conditions....
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Citrus; Biomass; Carbohydrate; Leaf gas exchange; Acclimation.
Ano: 2012
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202012000100006

Vegetative responses to temperature and photoperiod in saplings of brazilwood (Caesalpinia echinata Lam., Leguminosae)
Provedor de dados: 61
Autores: Rondon,Josimara N.; Zaidan,Lilian B.P.; Domingos,Marisa; Barbedo,Claudio J.; Figueiredo-Ribeiro,Rita de Cássia L.
Caesalpinia echinata Lam. (brazilwood) is an endangered tree species occurring along the eastern coast of Brazil from latitudes 5°56´S to 22°56´S. With such a range of distribution it is expected that temperature and daylength may affect plant development, which was examined in this study. One- and five-year-old saplings were grown under controlled photoperiods of 8 h, 12 h and 20 h, and in a greenhouse under natural light during 16 months. In another experiment, one-year-old saplings were cultivated for six months in a growth cabinet, with reduced maximum temperature, and in the greenhouse. Leaf number, stem height and stem diameter at the soil surface were evaluated every two months (experiment 1) or every month (experiment 2). In experiment 1, no...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Atlantic forest; Endangered species; Tree growth.
Ano: 2006
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202006000400004

Isolation of enzymes involved in threonine biosynthesis from sorghum seeds
Provedor de dados: 61
Autores: Ferreira,Renato Rodrigues; Vendemiatti,Ariane; Meinhardt,Lyndel Wayne; Lea,Peter John; Azevedo,Ricardo Antunes.
Cereal seeds are poor in essential amino acids, particularly lysine, tryptophan and threonine. The amino acids lysine and threonine are synthesized in the aspartate pathway. Although most of the enzymes of the aspartate pathway have been isolated and characterized in higher plant species, the metabolism of lysine and threonine is totally unknown in sorghum. We have isolated two enzymes, aspartate kinase (AK) and homoserine dehydrogenase (HSDH) from sorghum. Optimum assay conditions were established for the determination of AK and HSDH activities. The highest level of activity was observed in immature seeds. AK was shown to be inhibited by threonine and lysine indicating the existence of at least two isoenzymes, one sensitive to threonine inhibition and the...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Amino acids; Aspartate kinase; Homoserine dehydrogenase; Lysine; Threonine.
Ano: 2004
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202004000200005

Bioreactors in coffee micropropagation
Provedor de dados: 61
Autores: Etienne,Hervé; Dechamp,E; Barry-Etienne,D; Bertrand,Bernóit.
In coffee, bioreactors are the most promising way for scaling-up micropropagation processes, particularly somatic embryogenesis. The availability of an efficient somatic embryogenesis process would allow the rapid mass production of heterozygous materials such as selected Coffea canephora clones and F1 Arabica hybrid varieties. For the last fifteen years, bioreactors (mechanically or pneumatically agitated bioreactors, temporary immersion bioreactors) have mostly been used on coffee to optimize the mass regeneration of somatic embryos from embryogenic tissues. This review presents the main results, obtained with several bioreactor models, concerning the different steps of the micropropagation process : i) the multiplication of embryogenic tissues, ii) the...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Coffea; Breeding; Liquid medium; Mass propagation; Somatic embryogenesis; Temporary immersion.
Ano: 2006
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202006000100005

Cd-tolerance markers of Pfaffia glomerata (Spreng.) Pedersen plants: anatomical and physiological features
Provedor de dados: 61
Autores: Gomes,Marcelo Pedrosa; Marques,Teresa Cristina Lara Lanza Sa e Melo; Martins,Giordane Augusto; Carneiro,Marília Mercia Lima Carvalho; Soares,Ângela Maria.
Physiological and anatomical features of Cd-tolerance in Pfaffia glomerata were examined by exposing plantlets to nutrient solutions with increasing Cd concentrations (0, 15, 45, and 90 µmol Cd L-1), and possible Cd-tolerance markers were established. Cd contents were found to be higher in roots than in shoots. According to the bio-concentration factor data, this species is effectively a Cd-hyperaccumulator, as previously attested. Cd induced the appearance of xeromorphic characteristics in leaves (decreased water potential, increased numbers and decreased stomata size) and increased root endodermis thickness. The enzymatic antioxidant systems of roots and leaves were differently affected by Cd. The coordinated activities of antioxidant enzymes were...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Adaptation; Cd-oxidative damage; Phytoextraction; Tolerance.
Ano: 2012
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202012000400008

Effects of different drying rates on the physiological quality of Coffea canephora Pierre seeds
Provedor de dados: 61
Autores: Rosa,Sttela Dellyzete Veiga Franco da; Brandão Júnior,Delacyr da Silva; Von Pinho,Édila Vilela de Resende; Veiga,André Delly; Silva,Luiz Hildebrando de Castro e.
Desiccation tolerance in seeds depends on the species, development stage and drying conditions, especially the water removal rate. Coffea seeds are considered of intermediate performance, because they tolerate relative dehydration compared to orthodox seeds and are sensitive to low temperatures. The objective of this study was to verify the effect of different drying rates on the viability and storability of Coffea canephora seeds. A complete randomized experimental design was used, in a factorial 3 x 5 x 2 design, with three drying rates (fast, intermediate and slow), five final mean water contents after drying (51, 42, 33, 22 and 15 %) and two storage temperatures (10 and 20°C). The germination and seed vigor assessments, using radicle protrusion,...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Coffee tree; Desiccation tolerance; Seeds; Seed storage.
Ano: 2005
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202005000200002

Occurrence of myo-inositol-1-phosphate phosphatase in pteridophytes: characteristics of the enzyme from the reproductive pinnules of Dryopteris filix-mas (L.) Schott
Provedor de dados: 61
Autores: Banerjee,Ritwika; Chhetri,Dhani R.; Adhikari,Jukta.
Evident myo-inositol-1-phosphate phosphatase (MIPP) activity has been detected both in the vegetative as well as in the spore-bearing organs of some selected pteridophytes having wide phylogenetic diversity. The basic characterization of this enzyme was carried out using the cosmopolitan fern Dryopteris filix-mas. The enzyme was partially purified from the cytosol fraction obtained from the reproductive pinnules of the plant to about 41-fold over the initial homogenate following low-speed centrifugation, streptomycin sulfate precipitation, 25-70% ammonium sulfate fractionation, CM Sephadex C-50 chromatography and finally gel-filtration on Ultrogel AcA 34. The apparent molecular weight of the native MIPP was estimated to be 94 kDa. The enzyme activity...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Dryopteris filix-mas; Myo-inositol-1-phosphate phosphatase; Pteridophytes; Reproductive pinnules.
Ano: 2007
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202007000200003

Autonomy and network modulation of photosynthesis and water relations of Coffea arabica in the field
Provedor de dados: 61
Autores: Camargo-Bortolin,Lívia H.G. de; Prado,Carlos H.B. A.; Souza,Gustavo M.; Novaes,Paula.
The degree of connection between leaf gas exchange and leaf water potential, and the autonomy of these variables in relation to meteorological conditions were determined in three cultivars of Coffea arabica during clear and cloudy days. High values of vapor pressure deficit, air temperature and photosynthetic photon flux density resulted in low leaf autonomy during a clear day, irrespective the degree of connection among leaf physiological variables. Tight synchronization between physiological and meteorological variables was considered one important cause of net photosynthesis (P N) decreasing during a clear day. In contrast, diurnal P N was around three times higher on a cloudy day, when all cultivars presented high autonomy. Principal component analyses...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Coffea canephora; Connectance degree; Daily net photosynthesis; System analysis; Water stress.
Ano: 2008
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202008000200006

Dietary intake and health effects of selected toxic elements
Provedor de dados: 61
Autores: Silva,André Luiz Oliveira da; Barrocas,Paulo R.G.; Jacob,Silvana do Couto; Moreira,Josino Costa.
Anthropogenic activities have being contributing to the spread of toxic chemicals into the environment, including several toxic metals and metalloids, increasing the levels of human exposure to many of them. Contaminated food is an important route of human exposure and may represent a serious threat to human health. This mini review covers the health effects caused by toxic metals, especially Cd, Hg, Pb and As, the most relevant toxic elements from a human health point of view.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Bioavailability; Contamination; Heavy metals; Metal toxicity.
Ano: 2005
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202005000100007

Seed phytate content and phosphorus uptake and distribution in dry bean genotypes
Provedor de dados: 61
Autores: Coelho,Cileide Maria Medeiros; Santos,Júlio Cesar Pires; Tsai,Siu Mui; Vitorello,Victor Alexandre.
Phytic acid is the major storage form of phosphorus in seeds of legumes and cereals. Since phytate can form complexes with proteins and minerals, reducing the digestive availability of these nutrients, it is usually regarded as an antinutrient, although recent work indicates that it has important beneficial roles as an antioxidant and anticarcinogen. Therefore, there is an interest in the assessment and manipulation of phytate contents in important food grains such as beans. The objective of this work was to compare eleven dry bean genotypes with regard to grain contents of P, phytate, inorganic P and protein and to examine if differences between genotypes could be explained by differences in grain protein content or in uptake and partitioning of P. Plants...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Inorganic phosphorus; Phaseolus; Phytic acid; Protein.
Ano: 2002
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202002000100007

Effect of hydrogen cyanamide on the endogenous hormonal content of pea seedlings (Pisum sativum L.)
Provedor de dados: 61
Autores: Guevara,Eric; Jiménez,Víctor M.; Herrera,Jorge; Bangerth,Fritz.
Tipo: Info:eu-repo/semantics/other
Ano: 2008
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202008000200008

Portable chlorophyll meter for the quantification of photosynthetic pigments, nitrogen and the possible use for assessment of the photochemical process in Carica papaya L.
Provedor de dados: 61
Autores: Torres Netto,Alena; Campostrini,Eliemar; Oliveira,Jurandi Gonçalves de; Yamanishi,Osvaldo Kiyoshi.
The techniques utilized to extract chlorophyll from plant materials are destructive and based on methods that use organic solvents. This study proposes the non-destructive quantification of chlorophyll and nitrogen concentration using a portable chlorophyll meter (SPAD-502). Further, was possible to establish relationships between chlorophyll fluorescence and SPAD-502 values. This methodology could save time, space and resources, and could be used for analysis of the photosynthetic processes. Papaya leaves (Solo and Formosa groups) of different ages were collected from 15-month-old plants cultivated in a commercial field in São Francisco de Itabapoana, Rio de Janeiro State (41(0):15W; 21(0):27S). Correlations were established between the chlorophyll...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Nutrient content; Photosynthetic pigments; SPAD-502.
Ano: 2002
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202002000300004

Oxidative processes during 'Golden' papaya fruit ripening
Provedor de dados: 61
Autores: Resende,Evellyn Couto Oliveira; Martins,Paula Fabiane; Azevedo,Ricardo Antunes de; Jacomino,Angelo Pedro; Bron,Ilana Urbano.
'Golden' papayas at maturity stage 1 (15% yellow skin) were chosen to study selected oxidative processes, the activity of antioxidant enzymes and lipid peroxidation in storage at 22°C, during the ripening of the fruit. An increase in ethylene production was observed on the second day of storage and it was followed by an increase in respiration. An increased activity of catalase, glutathione reductase and ascorbate peroxidase was observed concurrently or soon after this increase in ethylene production and respiration. The increased activity of these enzymes near the peaks of ethylene production and respiration is related to the production of oxidants accompanying the onset of ripening. On the fourth day of storage, there was an increased lipid peroxidation...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Carica papaya; Antioxidant system; Climacteric; Ethylene; Lipid peroxidation.
Ano: 2012
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202012000200002

Photosynthesis and antioxidant activity in Jatropha curcas L. under salt stress
Provedor de dados: 61
Autores: Campos,Mariana Lins de Oliveira; Hsie,Bety Shiue de; Granja,João Antônio de Almeida; Correia,Rafaela Moura; Almeida-Cortez,Jarcilene Silva de; Pompelli,Marcelo Francisco.
Biodiesel is an alternative to petroleum diesel fuel. It is a renewable, biodegradable, and nontoxic biofuel. Interest in the production of biodiesel from Jatropha curcas L. seeds has increased in recent years, but the ability of J. curcas to grow in salt-prone areas, such as the Caatinga semiarid region, has received considerably meager attention. The aim of this study was to identify the main physiological processes that can elucidate the pattern of responses of J. curcas irrigated with saline water, which commonly occurs in the semiarid Caatinga region. This study measured the activity of the antioxidant enzymes involved in the scavenging of reactive oxygen species, which include catalase (CAT) and ascorbate peroxidase (APX), as well as malondialdehyde...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Biodiesel; CAT and APX activities; Euphorbiaceae; H2O2 and MDA contents; Salinity.
Ano: 2012
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202012000100008

The effect of lead on the phytochemistry of Tithonia diversifolia exposed to roadside automotive pollution or grown in pots of Pb-supplemented soil
Provedor de dados: 61
Autores: Olivares,Elizabeth.
Tithonia diversifolia, a ruderal weedy species utilized in agroforestry, is widely distributed in the tropics, often being found in wasteland, margins of polluted city rivers and roadsides. The objective of this study was to compare plants sampled at a light and heavy traffic roadside for metal concentration and foliar compounds which may be related to senescence and/or detoxification of metals. The field survey was followed by an experiment in pots of Pb-acetate-supplemented soil to verify if the same response is obtained under controlled conditions with regard to Pb. The concentration of Pb in leaves and roots of plants sampled at a heavy traffic roadside was higher than in samples from a light traffic site. The content of Cr, Al, Fe, Cu and Ni was also...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Asteraceae; Metals; Mexican sunflower; Phenols; Pollution; Weeds.
Ano: 2003
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202003000300004

Effect of 28-homobrassinolide on growth, zinc metal uptake and antioxidative enzyme activities in Brassica juncea L. seedlings
Provedor de dados: 61
Autores: Sharma,Priyanka; Bhardwaj,Renu; Arora,Nitika; Arora,Hardesh Kumar.
The present work was undertaken to study the effects of 28-homobrassinolide on growth, zinc metal uptake, antioxidative enzyme [guaiacol peroxidase (EC 1.11.1.7), catalase (EC 1.11.1.6), glutathione reductase (EC 1.6.4.2), ascorbate peroxidase (EC 1.11.1.11), superoxide dismutase (EC 1.15.1.1)] activities and protein content in 7-d-old seedlings of Brassica juncea L. treated with Zn metal at different concentrations. 28-homobrassinolide at 10-9 M concentration lowered Zn uptake and bioconcentration factor. Different concentrations of Zn-metal treatment alone decreased the enzyme activities and protein concentration of seedlings. However, pre-sowing treatments of 28homobrassinolide lowered the uptake of metal and enhanced the activities of enzymes and...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Antioxidative enzymes; 28-homobrassinolide; Brassinosteroids; Zinc toxicity.
Ano: 2007
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202007000300004

Nitric oxide induced alleviation of toxic effects of short term and long term Cd stress on growth, oxidative metabolism and Cd accumulation in Chickpea
Provedor de dados: 61
Autores: Kumari,Anita; Sheokand,Sunita; Swaraj,Kumari.
The present study investigates the effect of long and short term Cd stress in chickpea plants and evaluates the protective effect of exogenous nitric oxide (NO) supplementation using sodium nitroprusside (SNP). Cadmium treatments were given before sowing (long term stress) and thirty days after germination (short term stress). Sodium nitroprusside was given as foliar spray 30 days after germination to both long and short term Cd treated plants. Cadmium adversely affected the membranes as was evident from increased electrolyte leakage and lipid peroxidation levels. Sodium nitroprusside treatments decreased ion leakage and lipid peroxidation levels significantly. Short term Cd stress resulted in a higher induction of the catalase, peroxidase, ascorbate...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Antioxidant enzymes; Lipid peroxidation; Membrane injury; Sodium nitroprusside.
Ano: 2010
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202010000400007

Photosynthetic performance and anatomical adaptations in Byrsonima sericea DC. under contrasting light conditions in a remnant of the Atlantic forest
Provedor de dados: 61
Autores: Silva,Anandra S.; Oliveira,Jurandi G.; Cunha,Maura da; Vitória,Angela P.
The photosynthetic dynamics of the tropical pioneer species, Byrsonima sericea DC., were studied during the regeneration process of a native forest by evaluating ecophysiological (gas exchange, chlorophyll a fluorescence and photosynthetic pigment contents) and anatomical parameters of plants in sunny and shady environments. Ecophysiological evaluations were carried out monthly for one year, encompassing both a dry and a rainy season. Byrsonima sericea DC. presents anatomical plasticity that enables it to establish in environments with contrasting light regimes. In sunny conditions, it produced a thicker leaf (about 420 mm) and flat adaxial epidermis, whilst in the shade, leaves had a thinner convex adaxial epidermis (about 395 mm). No differences were...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Atlantic forest species; Photosynthetic adaptation; Leaf anatomy; Sun overexposure; Shaded plants.
Ano: 2010
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202010000400004

Ameliorative effect of exogenous nitric oxide on oxidative metabolism in NaCl treated chickpea plants
Provedor de dados: 61
Autores: Sheokand,Sunita; Bhankar,Vinita; Sawhney,Veena.
Accumulation of salts in irrigated soils is one of the primary factors limiting yield in South Asia. We investigated whether exogenous nitric oxide (NO) supplementation as sodium nitroprusside has any ameliorating effect against NaCl induced oxidative damage in chickpea leaves. NaCl treatment (250 mM) alone and in combination with two concentrations of SNP (0.2 and 1 mM) were given to 50 days old chickpea plants for 2, 4 and 6 days. Salt stress adversely affected the relative membrane injury, lipid peroxidation levels, relative water content (RWC) and H2O2 content. The effect was time dependent. SNP treatments could ameliorate the toxic effect of short term salt stress of 2 days on relative membrane injury and partial amelioration was observed with 4 and 6...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Antioxidant enzymes; Chickpea; Lipid peroxidation; Nitric oxide; Salt stress.
Ano: 2010
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202010000200002

Aspects of nitrogen metabolism in coffee plants
Provedor de dados: 61
Autores: Carelli,Maria Luiza Carvalho; Fahl,Joel Irineu; Ramalho,José D. Cochicho.
Coffee plants are highly N-demanding plants. Despite the importance of N nutrition for the development, acclimation and yield of coffee plants, there are few reports concerning N metabolism in this species. In this review, our intention is to summarize the information available in the literature and to point out the influence of environmental conditions on N assimilation, as well as comment and discuss some apparently contradictory results and raise and enlighten queries about N assimilation in coffee plants.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Coffea; Irradiance level; Nitrate reductase; Nitrogen fertilization; Oxidative stress; Photoinhbition; Photoprotection; Photosynthesis.
Ano: 2006
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202006000100002

Cell wall biochemistry of sapodilla (Manilkara zapota) submitted to 1-methylcyclopropene
Provedor de dados: 61
Autores: Morais,Patrícia L.D.; Miranda,Maria R.A.; Lima,Luis C.O.; Alves,José D.; Alves,Ricardo E.; Silva,José D.
Sapodilla (Manilkara zapota) is a climacteric fruit that ripens shortly after harvest. Studies on its conservation during storage have been mainly restricted to using low temperatures and modified atmospheres. In this study we investigated the influence of 1-methylcyclopropene (1-MCP) on the physiological and biochemical changes that sapodilla cell wall undergoes during ripening and evaluated its potential to preserve sapodilla fruits at postharvest. Fruits were treated with ethylene antagonist 1-MCP at 300 nL L-1 for 12 h and then stored under a modified atmosphere at 25ºC for 23 d. 1-MCP significantly delayed softening of sapodilla for 11 d as a consequence of inhibition of cell wall degrading enzyme activities, and thus 1-MCP-treated fruit exhibited a...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Cell wall hydrolases; Ethylene; Hemicellulose; Neutral sugar; Fruit ripening; Uronides.
Ano: 2008
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202008000200001

Changes in growth, pigment content and antioxidants in the root and leaf tissues of wheat plants under the influence of exogenous salicylic acid
Provedor de dados: 61
Autores: Sahu,Gopal Krishna; Sabat,Surendra Chandra.
The effect of various concentrations of salicylic acid (SA) on the growth, pigment content and the activity of antioxidants was investigated in the laboratory grown wheat plants. The root and shoot growth was affected at higher concentration of SA in early days of growth. The activities of catalase (CAT), ascorbate peroxidase (APX) and guaicol-specific peroxidase (POX) declined with the application of SA (50, 500 and 1000 µM), the decrease being more pronounced with the increase in SA concentrations both in the root and leaf tissues. On the other hand superoxide dismutase (SOD) activity increased with the application of SA. At low concentrations, SA has no effect on the activities of these enzymes in vitro. Salicylic acid at higher concentrations (5- and...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Antioxidants; Oxidative stress; Salicylic acid; Triticum aestivum L.
Ano: 2011
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202011000300005

Xylem sap analysis reveals new facts of salt tolerance in rice genotypes
Provedor de dados: 61
Autores: Roshandel,Parto.
Salinity damage in rice and other salt-sensitive species is due to excessive transport of NaCl through the root system to the leaves and consequently low salt transport to the shoot can be a major trait determining salt resistance. Since the rapid uptake of sodium ions is such a crucial part of the response of rice to salinity, physiological experiments were carried out to compare bypass flow in two genotypes of rice (IR4630 and IR15324) differing in salt tolerance, because it has been suggested that an apoplastic pathway, bypass flow, is a major contributory pathway for Na+ entrance into rice plants. Experiments on the youngest fully expanded photosynthetic leaf (the third from the base), using PTS as a tracer for apoplastic movement and Philaenus...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Bypass flow; Na+ transport; Oryza sativa; Philaenus spumarius; Salt stress; Xylem concentration.
Ano: 2007
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202007000300002

Ecophysiology of coffee growth and production
Provedor de dados: 61
Autores: DaMatta,Fábio M.; Ronchi,Cláudio P.; Maestri,Moacyr; Barros,Raimundo S.
After oil, coffee is the most valuable traded commodity worldwide. In this review we highlighted some aspects of coffee growth and development in addition to focusing our attention on recent advances on the (eco)physiology of production in both Coffea arabica and C. canephora, which together account for 99% of the world coffee bean production. This review is organized into sections dealing with (i) climatic factors and environmental requirements, (ii) root and shoot growth, (iii) blossoming synchronisation, fruiting and cup quality, (iv) competition between vegetative and reproductive growth and branch die-back, (v) photosynthesis and crop yield, (vi) physiological components of crop yield, (vii) shading and agroforestry systems, and (viii) high-density...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Arabica conilon and robusta coffee beverage quality density planting die-back flowering photosynthesis; Shading.
Ano: 2007
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202007000400014

Desiccation tolerance in seeds of Annona emarginata (Schldtl.) H. Rainer and action of plant growth regulators on germination
Provedor de dados: 61
Autores: Corsato,Jaqueline Malagutti; Ferreira,Gisela; Barbedo,Claudio Jose.
Annona emarginata (Schldtl.) H. Rainer ("araticum-de-terra-fria") is used as a rootstock for several species of Annonaceae. It is suggested that these seeds should be sown immediately after extraction and, therefore, they could be intolerant to desiccation. There are several mechanisms involved with desiccation tolerance. Soluble sugars, for example, can accumulate and act as osmoprotectants for the membrane system during desiccation. The aim of this study is to assess desiccation tolerance in A. emarginata seeds. In addition, we examined the soluble sugars involved in desiccation tolerance. Finally, we determined the effect of gibberellic acid (GA4+7) and N-(phenylmethyl)-aminopurine in promoting the germination of seeds with different water contents. The...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Araticum-de-terra-fria; Desiccation; Cytokinins; Gibberellins; Soluble sugars.
Ano: 2012
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202012000400004

Possible involvement of proteasome activity in ethylene-induced germination of dormant sunflower embryos
Provedor de dados: 61
Autores: Borghetti,Fabian; Noda,Fabio Nakamura; Sá,Cezar Martins de.
Freshly harvested sunflower seeds (Helianthus annuus L., Asteraceae) present physiological dormancy localized at the embrionary axis which prevents germination at low temperatures. However, dormant embryos reach about 100 % germination when incubated with the phytohormone ethylene during imbibition. To examine whether proteinase activities are implicated in the breaking of dormancy by ethylene, dormant embryos were treated with the proteinase inhibitors leupeptin, E64 and the proteasome specific inhibitor clasto-lactacystin ß-lactone (lactacystin). A few embryos (&lt; 10 %) germinated at 10 ºC in absence of ethylene but ethylene-treated embryos reached high germinability (~90 %) in the presence of leupeptin, E64, water and DMSO. On the other hand,...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Helianthus annuus; Dormancy; Ethylene; Lactacystin; Proteasome.
Ano: 2002
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202002000200007

The importance of evolutionary history in studies of plant physiological ecology: examples from cerrados and forests of central Brazil
Provedor de dados: 61
Autores: Hoffmann,William A.; Franco,Augusto C.
Studies that compare physiology, anatomy, and ecology across species have offered some of the best insight into adaptation and evolutionary constraints in plants. As a result, the comparative approach has become increasingly used in studies of plant physiological ecology. The high species diversity of Brazilian biomes provides many excellent opportunities for comparative plant ecophysiology, and could be better exploited for understanding the evolution of plant form and function. In this paper we emphasize the importance of considering phylogenetic information for the design and analysis of comparative studies, relying on examples from comparisons of woody plants from cerrado and gallery (riparian) forests. The use of congeneric species pairs, each...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Cerrado; Forest; Specific leaf area; Leaf area ratio; Phylogeny.
Ano: 2008
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202008000300008

Structural cell wall proteins from five pollen species and their relationship with boron
Provedor de dados: 61
Autores: García-Hernández,Edith del R.; López,Gladys I. Cassab.
Boron (B) is an essential micronutrient for the survival of vascular plants. The most severe effect derived from a deficiency of B is the alteration of cell wall biogenesis and pollen germination. We investigated pollen of plant species that require B for germination (Zea may L. and Nicotiana tabacum L.), as well as those that can germinate without B (Pinus sp, Lilum longiflorum, Impatiens sp.). In both groups, B addition in the growth medium increased the length of the pollen tube after germination. Hydroxyproline Rich Glycoproteins (HRGPs) are the most abundant cell wall structural proteins of dicotyledonous plants and the sexual tissues of monocotyledonous plants. Here, we show that maize pollen accumulated a significant pool of hydroxyproline (Hyp) and...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Cell wall; HRGPs; Hydroxyproline; Pollen tube.
Ano: 2005
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202005000400005

Physiological characteristics of cassava tolerance to prolonged drought in the tropics: implications for breeding cultivars adapted to seasonally dry and semiarid environments
Provedor de dados: 61
Autores: El-Sharkawy,Mabrouk A.
The paper summarizes research conducted at International Center for Tropical Agriculture (CIAT) on responses of cassava to extended water shortages in the field aided by modern gas-exchange and water-relation techniques as well as biochemical assays. The aim of the research was to coordinate basic and applied aspects of crop physiology into a breeding strategy with a multidisciplinary approach. Several physiological characteristics/traits and mechanisms underpinning tolerance of cassava to drought were elucidated using a large number of genotypes from the CIAT core germplasm collection grown in various locations representing ecozones where cassava is cultivated. Most notable among these characteristics are the high photosynthetic capacity of cassava leaves...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Agriculture; Breeding; Canopy; Carboxylation enzymes; C3-C4 intermediate; Ecophysiology; Growth; Leaf photosynthesis; Manihot sp.; PEP carboxylase; Productivity; Stomata; Water stress; Yield.
Ano: 2007
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202007000400003

On-line HPLC analysis of the antioxidant activity of phenolic compounds in brewed, paper-filtered coffee
Provedor de dados: 61
Autores: Stalmach,Angélique; Mullen,William; Nagai,Chifumi; Crozier,Alan.
Caffeoyl-, feruloyl- and dicaffeoylquinic acids (chlorogenic acids) in infusions from green and medium roasted coffee beans were identified and quantified by reverse phase HPLC with photodiode array and MS³ detection prior to assessment of the antioxidant activity using an HPLC system with post-column on-line antioxidant detection based on 2,2'-azinobis-3-ethylbenzothiazoline-6-sulphonic acid radical scavenging activity. Caffeoylquinic acids were the most abundant antioxidants and roasting induced isomerisation with a decline in 5-O-caffeoylquinic acid and concomitant increases in the 3- and 4-O-derivatives. This did not affect the level of caffeoylquinic acid-derived antioxidant activity in the roasted coffee. Roasting did, however, result in the...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Coffea; ABTS+; Chlorogenic acids; Hydroxycinnamates; HPLC-MSn.
Ano: 2006
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202006000100018

Narrow band spectral indexes for chlorophyll determination in soybean canopies [Glycine max (L.) Merril]
Provedor de dados: 61
Autores: Ferri,Clotilde Pinheiro; Formaggio,Antonio Roberto; Schiavinato,Marlene Aparecida.
Photosynthetic pigments are essential for plant development. Quantifying these pigments in great extensions of agricultural crops is an important objective in remote sensing for agricultural purposes. This information can be used to produce a more accurate estimation of the physiological state of the vegetation, for species discrimination and productivity estimation. The aim of the present study was to (a) evaluate the potential for estimating chlorophyll content of crop canopies, using narrow band spectral indexes, and (b) in this respect compare the performances of NDVI (a multispectral wide band index) and two narrow band vegetation indexes (R750/700 and R750/550). Experiments were carried out under greenhouse conditions whereby soybean [Glycine max...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Canopy chemistry; Hyperspectral remote sensing; Remote sensing in agriculture; Spectroradiometry.
Ano: 2004
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202004000300002

Heavy metals, Co, Ni, Cu, Zn and Cd, produce oxidative damage and evoke differential antioxidant responses in spinach
Provedor de dados: 61
Autores: Pandey,Nalini; Pathak,Girish C.; Pandey,Dharmendra K.; Pandey,Ritu.
Exposure of 10-d-old spinach (Spinacea oleracea L.) plants to excess (500 µM) concentrations of Co, Ni, Cu, Zn and Cd in sand culture inhibited growth, induced toxicity symptoms, oxidative damage and changes in the antioxidant defense system. The severity of the metal-induced effects varied with the metals and the duration of exposure to excess supply of the metals. Each metal induced chlorosis. In addition, excess Co, Ni and Cd also produced metal specific toxic effects. Excess supply of each metal caused lipid peroxidation (TBARS). Their effectiveness in producing oxidative damage was in the order: Ni &gt; Co &gt; Cd &gt; Cu &gt;Zn. Of all the metals, Ni was also most effective in lowering the concentration of the chloroplast pigments (Chl, Car). While...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Ascorbate-glutathione cycle; Heavy metal exposure; Spinacia oleracea L.
Ano: 2009
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202009000200003

Physiological and biochemical traits as tools to screen sensitive and resistant varieties of tomatoes exposed to salt stress
Provedor de dados: 61
Autores: Fariduddin,Qazi; Mir,Bilal Ahmad; Ahmad,Aqil.
The present study was conducted to evaluate salt tolerance in seven different pure-line cultivars of tomato (Solanum lycopersicum L.) viz. K-21, Pusa Ruby, Pusa Gorav, Hera research, Selection N5, PKM-1 and S-22 based on several physiological and biochemical traits. Seedlings were transplanted to the pots, being exposed to different salinity levels in the form of NaCl (0, 50, 100, or 150 mM) at a 35-day stage of growth for six days. The plants exposed to salt stress presented a significant decline in growth, photosynthetic parameters, maximum quantum yield of PSII and leaf water relations, which were drastically reduced in variety S-22, while variety K-21 was the least affected. Electrolyte leakage was superior in proportion to an increase in salinity...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Salt tolerance; Solanum lycopersicum L.; Physiological and biochemical traits; Screening.
Ano: 2012
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202012000400007

Light as an indicator of ecological succession in brazilwood (Caesalpinia echinata Lam.)
Provedor de dados: 61
Autores: Mengarda,Liana H. G.; Souza,Rogério L. F. de; Campostrini,Eliemar; Reis,Fabrício O.; Vendrame,Wagner A.; Cuzzuol,Geraldo R. F.
The ecophysiological behavior of brazilwood (Caesalpinia echinata Lam.) plants was evaluated as affected by light quantity and quality. Nine-month-old plants were cultivated under 0%, 50%, and 80% artificial shading, and natural shading imposed by a closed canopy for a period of 392 days. At the end of that period growth parameters were measured, including relative growth rate (RGR), net assimilation rate (NAR), leaf area ratio (LAR), specific leaf mass (SLM) and root:shoot ratio (R:S). Higher leaf area, dry mass and RGR were obtained under 50% artificial shade. Under full sunlight (0% shade), growth was satisfactory showing higher R:S and SLM. Growth was inhibited under 80% artificial and natural shading indicating that C. echinata is not...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Chlorophyll fluorescence; Gas exchange; Growth; Light stress; Shade; Tropical tree.
Ano: 2009
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202009000100007

Amino acid and ureide transport in the xylem of symbiotic soybean plants during short-term flooding of the root system in the presence of different sources of nitrogen
Provedor de dados: 61
Autores: Thomas,André Luís; Sodek,Ladaslav.
The transport of organic N compounds to the shoot in the xylem sap of nodulated soybean plants was investigated in an attempt to better understand the changes in N metabolism under root hypoxia (first 5 days of flooding), with different sources of N in the medium. NO3- is beneficial for tolerance of plants to waterlogging, whereas other N sources such as NH4+ and NH4NO3, are not. Nevertheless, in the presence of NH4+ high levels of amino acids were transported in the xylem, consistent with its assimilation. Some increase in the transport of amino acids was also seen with NO3- nutrition during waterlogging, but not with N-free medium. Ureide transport in the xylem was severely reduced during waterlogging, consistent with impaired N2 fixation under these...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Glycine max; Alanine; Hypoxia; N metabolism.
Ano: 2006
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202006000200010

Induction of phenolics and defense-related enzymes in coconut (Cocos nucifera L.) roots treated with biocontrol agents
Provedor de dados: 61
Autores: Karthikeyan,M.; Radhika,K.; Mathiyazhagan,S.; Bhaskaran,R.; Samiyappan,R.; Velazhahan,R.
The effect of soil application of biocontrol agents (Pseudomonas fluorescens, Trichoderma viride and T. harzianum) in combination with chitin on induction of phenolics and defense enzymes in coconut roots infected with Ganoderma lucidum, the causal agent of Ganoderma disease, was investigated. Soil application of these biocontrol formulations in combination with chitin induced a significant increase in the activities of peroxidase (PO), polyphenol oxidase (PPO), phenylalanine ammonia-lyase (PAL), chitinase and beta-1,3-glucanase in the G. lucidum infected palms. Activities of both PAL and PO reached maximum levels within 3 d while the activity of PPO reached the maximum level 6 d after application of a mixture of P. fluorescens, T. viride and chitin....
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Chitin; Ganoderma disease; Induced systemic resistance; Pathogenesis-related proteins; Phenolics; Pseudomonas fluorescens; Trichoderma.
Ano: 2006
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202006000300003

Coffee leaf miner resistance
Provedor de dados: 61
Autores: Guerreiro Filho,Oliveiro.
The coffee leaf miner, Leucoptera coffeella, is a common pest of coffee plantations in Brazil. Though it is effective, chemical control substantially increases the cost of production and constitutes a significant risk for the environment. Resistant coffee cultivars have been and continue being developed through classic and molecular selection techniques. Basic knowledge about the biology of this insect, the damage it causes to the plants, the identification of sources of resistance, the development of efficient selection methods and knowledge about the genetics of resistance have contributed to the efficiency of the ongoing genetic improvement programs. Recently, coffee genomics studies have also promoted an improvement in the efficiency of the development...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Coffea; Defense mechanisms; Leucoptera coffeella; Plant-insect interaction.
Ano: 2006
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202006000100009

Physiological and oxidative stress responses of four potato clones to aluminum in nutrient solution
Provedor de dados: 61
Autores: Tabaldi,Luciane A.; Nicoloso,Fernando T.; Castro,Gabriel Y.; Cargnelutti,Denise; Gonçalves,Jamile F.; Rauber,Renata; Skrebsky,Etiane C.; Schetinger,Maria R.C.; Morsch,Vera M.; Bisognin,Dilson A.
Aluminum toxicity is a serious problem in Brazilian soils and selecting potato clones is an important strategy to produce this crop on these kinds of soils. Potato clones, Macaca, SMIC148-A, Dakota Rose, and Solanum microdontum, were grown in a nutrient solution (pH 4.0) with 0, 50, 100, 150 and 200 mg Al L-1. After 7 d, Al concentration in both root system and shoot of all clones increased linearly with increasing Al levels. Based on relative root growth, S. microdontum and SMIC148-A were considered Al-tolerant clones, whereas Macaca and Dakota Rose were considered Al-sensitive. Shoot growth in Macaca linearly decreased with increasing Al levels. Root H2O2 concentration in both Al-sensitive clones increased with increasing Al supply, whereas in...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Aluminum toxicity; Antioxidative enzymes; Growth; Oxidative stress; Solanum tuberosum.
Ano: 2007
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202007000300005

An outlook on ion signaling and ionome of mycorrhizal symbiosis
Provedor de dados: 61
Autores: Ramos,Alessandro C.; Façanha,Arnoldo R.; Palma,Livia M.; Okorokov,Lev A.; Cruz,Zilma M.A.; Silva,Ary G.; Siqueira,Arthur F.; Bertolazi,Amanda A.; Canton,Gabriela C.; Melo,Juliana; Santos,Wolmen O.; Schimitberger,Vanusa M. B.; Okorokova-Façanha,Anna L.
The 450-million-year-old interaction between the majority of land plants and mycorrhizal fungi is one of the most ancient, abundant, and ecologically important symbiosis on earth. The early events in the evolution of mycorrhizal symbioses seem to have involved reciprocal genetic changes in ancestral plants and free-living fungi. new data on the mechanism of action of specific signaling molecules and how it influence and is influenced by the membrane ions fluxes and cytoplasm ion oscillations which integrate the symbiotic ionome are improving our understanding of the molecular bases of the mycorrhization process. This mini-review will highlight topics regarding what is known about the ionome and ionic communication in the arbuscular mycorrhizal symbiosis...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Ion dynamics; Íon signaling; Mycorrhiza; Ionomics; Plant synapsis.
Ano: 2011
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202011000100010

Chlorophyll a fluorescence as indicative of the salt stress on Brassica napus L.
Provedor de dados: 61
Autores: Bacarin,Marcos Antonio; Deuner,Sidnei; Silva,Fabio Sergio Paulino da; Cassol,Daniela; Silva,Diolina Moura.
The effects of salinity stress on chlorophyll fluorescence and the growth of Brassica napus L were investigated. The chlorophyll a fluorescence transient were recorded and analyzed according to the JIP-test which can quantify PSII performance. Salt stress resulted in decreased leaf area and dry matter compared with the control treatment (0 mM NaCl). The most pronounced effects of salt stress were observed with 200 mM NaCl, and the hybrids displayed different levels of sensitivity to stress. The Performance Index (PI ABS) was the most sensitive parameter to salt stress, which suggests that this parameter can be used to screen genotypes for salt tolerance.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Canola; Growth; JIP-Test/salt stress; Spring rapessed oil.
Ano: 2011
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202011000400001

Leaf water potential, gas exchange and chlorophyll a fluorescence in acariquara seedlings (Minquartia guianensis Aubl.) under water stress and recovery
Provedor de dados: 61
Autores: Liberato,Maria Astrid Rocha; Gonçalves,José Francisco de Carvalho; Chevreuil,Larissa Ramos; Nina Junior,Adamir da Rocha; Fernandes,Andreia Varmes; Santos Junior,Ulysses Moreira dos.
The physiological performance of acariquara (Minquartia guianensis) seedlings submitted to water deficit and the recovery of physiological parameters during rehydration were investigated in a greenhouse experiment. The analyzed parameters were: leaf water potential, gas exchange and chlorophyll a fluorescence. After thirty-five days, non-irrigated plants exhibited a leaf water potential 70 % lower compared to control plants (irrigated daily) and the stomatal conductance reached values close to zero, inducing a severe decrease in gas exchange (photosynthesis and transpiration). Six days after the beginning of the rehydration of drought-stressed plants, the results demonstrated that water stress did not irreversibly affect gas exchange and quantum efficiency...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Chlorophyll a fluorescence; Photochemical efficiency of PSII; Stress physiology; Tree species; Water deficit.
Ano: 2006
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202006000200008

Photosynthesis and cell respiration modulated by water deficit in grapevine (Vitis vinifera L.) cv. Cabernet Sauvignon
Provedor de dados: 61
Autores: Martim,Sílvia A.; Santos,Mirella P.; Peçanha,Anderson L.; Pommer,Celso; Campostrini,Eliemar; Viana,Alexandre P.; Façanha,Arnoldo R.; Bressan-Smith,Ricardo.
Winegrape productivity and quality has been related to the regulated deficit irrigation, with important implications for the plant bioenergetics. When water deficit is imposed to grapevine plants, alterations in overall photosynthesis and cell respiration are observed. The aim of this study was to assess the modulations promoted by water stress on photosynthesis and respiration in leaves of the cv. Cabernet Sauvignon (cv. CS) for better understanding the physiological responses related to its drought tolerance and quality improvement under water deficit. For this purpose, measurements of photosynthetic efficiency, leaf water potential, gas exchange and O2 consumption were carried out. Leaf water potential, photosynthesis, stomatal conductance,...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Vitis vinifera; Drought tolerance; Irrigation management; Respiratory chain regulation; Plant bioenergetics.
Ano: 2009
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202009000200002

III.Heat stress in Triticum: kinetics of Na, K and P accumulation
Provedor de dados: 61
Autores: Dias,Ana S.; Fernando,Ana L.; Lidon,Fernando C.
Genotypes of bread and durum wheat were submitted to heat stress after anthesis and the accumulation of Na, K and P, at booting, grain filling and maturity, were investigated. It was found that, after anthesis, the levels of Na in shoots were considerably higher in durum relatively to bread wheat, being this trend also observed in the total plant accumulation. In these genotypes, heat stress affected significantly Na concentration in shoots. In general, heat stressed plants had significant higher levels of K in the shoots and the proportion of this nutrient translocation from the roots also increased with heat stress. In general, the levels of P didn't show significant differences with heat stress. The effects of heat stress among the wheat genotypes life...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Triticum aestivum L.; Triticum turgidum subsp. Durum; Heat stress; Nutrients uptake; Nutrients translocation.
Ano: 2009
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202009000200007

Intraspecific variation in sensitivity to ambient ultraviolet-B radiation in growth and yield characteristics of eight soybean cultivars grown under field conditions
Provedor de dados: 61
Autores: Baroniya,Sanjay S.; Kataria,Sunita; Pandey,G.P.; Guruprasad,Kadur N.
The present study was conducted with eight cultivars of soybean (Glycine max) to determine the effect of exclusion of solar UV-B on the vegetative growth (plant height, leaf area, no. of nodes), UV absorbing compounds (implicated in UV protection) and crop yield (No. of pods and seed weight) and to determine the cultivar difference in their sensitivity to ambient UV-B. Exclusion of solar UV-B enhanced the vegetative growth and yield of all the soybean cultivars. The results showed a significant inverse association between the enhancement in vegetative growth and number of pods among the cultivars tested, indicating differences in the carbon partitioning amongst the cultivars by the way of exclusion of solar UV-B. NRC-7, Pusa-24 and JS-335 showed maximum...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Exclusion; Leaf Area; Sensitivity index; UV-Absorbing substances.
Ano: 2011
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202011000300003

Challenges in proteome analyses of tropical plants
Provedor de dados: 61
Autores: Balbuena,Tiago S.; Dias,Leonardo L. C.; Martins,Mariana L. B.; Chiquieri,Tatiana B.; Santa-Catarina,Claudete; Floh,Eny I. S.; Silveira,Vanildo.
Genome sequencing of various organisms allow global analysis of gene expression, providing numerous clues on the biological function and involvement in the biological processes studied. Proteomics is a branch of molecular biology and biotechnology that has undergone considerable development in the post-genomic era. Despite the recent significant advancements in proteomics techniques, still there is much to be improved. Due to peculiarities to the plant kingdom, proteomics approaches require adaptations, so as to improve efficiency and accuracy of results in plants. Data generated by proteomics can substantially contribute to the understanding and monitoring of plant physiological events and development of biotechnological strategies. Especially for...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: 2-DE; Mass spectrometry; Recalcitrant species; Proteomics; Unknown genome.
Ano: 2011
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202011000200001

Interactions between leaf water potential, stomatal conductance and abscisic acid content of orange trees submitted to drought stress
Provedor de dados: 61
Autores: Gomes,Mara de Menezes de Assis; Lagôa,Ana Maria Magalhães Andrade; Medina,Camilo Lázaro; Machado,Eduardo Caruso; Machado,Marcos Antônio.
Thirty-month-old 'Pêra' orange trees grafted on 'Rangpur' lemon trees grown in 100 L pots were submitted to water stress by the suspension of irrigation. CO2 assimilation (A), transpiration (E) and stomatal conductance (g s) values declined from the seventh day of stress, although the leaf water potential at 6:00 a.m. (psipd) and at 2:00 p.m. (psi2) began to decline from the fifth day of water deficiency. The CO2 intercellular concentration (Ci) of water-stressed plants increased from the seventh day, reaching a maximum concentration on the day of most severe stress. The carboxylation efficiency, as revealed by the ratio A/Ci was low on this day and did not show the same values of non-stressed plants even after ten days of rewatering. After five days of...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Abscisic acid; Citrus sinensis; Gas exchanges; Water stress.
Ano: 2004
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202004000300005

Stomatal changes induced by intermittent drought in four umbu tree genotypes
Provedor de dados: 61
Autores: Silva,Elizamar C.; Nogueira,Rejane J. M. C.; Vale,Fernando H. A.; Araújo,Francisco P. de; Pimenta,Mariana A.
Transpiration (E), diffusive resistance (r s) and anatomical parameters were measured in plants of four grafted umbu tree genotypes (GBUs 44, 48, 50 and 68) in order to evaluate alterations induced by intermittent drought and possible genotypic variations. Transpiration measurements were taken daily until stomatal closure by withholding water. Measurements were also taken, when the plants were re-watered and the watering was interrupted again. This cycle was repeated for a period of 31 days (stress period). The control plants were also irrigated daily. A regular pattern in the stomatal opening/closing mechanism was observed throughout the watering period, exhibiting intra-specific differences. Stomatal behavior of GBU 44 and GBU 68 were influenced by air...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Diffusive resistance; Spondias tuberosa; Stomatal density; Transpiration; Water deficit.
Ano: 2009
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202009000100005

Changes in physiological indicators associated with salt tolerance in two contrasting cashew rootstocks
Provedor de dados: 61
Autores: Ferreira-Silva,Sérgio L.; Silveira,Joaquim A.G.; Voigt,Eduardo L.; Soares,Lucilene S.P.; Viégas,Ricardo A.
In order to identify salt tolerance indicators, several physiological variables were evaluated in two contrasting cashew (Anacardium occidentale L.) rootstocks in response to salt stress. The tolerant CCP 09 genotype showed better growth performance after two weeks under a large range of NaCl salinity (50, 100, 150 and 200 mM). The NaCl treatments induced a significant drop in transpiration as a consequence of an increased stomatal resistance in both genotypes. No significant differences in Na+, Cl, and K+ concentrations were found in both roots and leaves regardless of rootstocks. The tolerant genotype exhibited lower relative water content and less negative leaf osmotic potential as compared with the sensitive genotype and, therefore, these variables...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Anacardium occidentale; Organic solutes; Salt stress; Salt tolerance; Sodium and chloride partitioning; Sodium-to-potassium ratio.
Ano: 2008
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202008000100006

Phytotranslocation of Fe by biodiesel plant Jatropha curcas L. grown on iron rich wasteland soil
Provedor de dados: 61
Autores: Ghavri,Surendra Vikram; Singh,Rana P.
Experiments were conducted to evaluate the plant tolerance to Fe and its phytotranslocation by Jatropha curcas L. from an iron rich wasteland soil. The soil was collected from wasteland soil (WLS) of a small town Sandila, (Hardoi, U.P.) India, and three Jatropha clones were cultivated in WLS amended or not with sand or cowdung in a ratio of 3:2. The WLS had high pH, elevated electric conductivity (EC) and was rich in organic carbon and total NPK. Iron and Mn were 2-3 folds higher than that in the normal field soil. Net root and shoot elongation as well as fresh and dry biomass of the plants were only slightly affected at 100 d in WLS as compared with that grown in non-polluted soil. Tolerance index (TI) of J. curcas was significantly higher in cowdung...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Bio-accumulation; Bio-concentration factor; Concentration index; Phytoremediation; Tolerance index.
Ano: 2010
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202010000400003

Cadmium toxicity in plants
Provedor de dados: 61
Autores: Benavides,María P.; Gallego,Susana M.; Tomaro,María L.
Heavy metals are important environmental pollutants and their toxicity is a problem of increasing significance for ecological, evolutionary, nutritional, and environmental reasons. Plants posses homeostatic cellular mechanisms to regulate the concentration of metal ions inside the cell to minimize the potential damage that could result from the exposure to nonessential metal ions. This paper summarizes present knowledge in the field of higher plant responses to cadmium, an important environmental pollutant. Knowledge concerning metal toxicity, including mechanisms of cadmium homeostasis, uptake, transport and accumulation are evaluated. The role of the cell wall, the plasma membrane and the mycorrhizas, as the main barriers against cadmium entrance to the...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Cadmium; Heavy metals; Metal toxicity; Phytochelatins; Oxidative stress.
Ano: 2005
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202005000100003

Tolerance and prospection of phytoremediator woody species of Cd, Pb, Cu and Cr
Provedor de dados: 61
Autores: Almeida,Alex-Alan F. de; Valle,Raúl R.; Mielke,Marcelo S.; Gomes,Fábio P.
High concentrations of Cd, Pb, Cu and Cr can cause harmful effects to the environment. These highly toxic pollutants constitute a risk for aquatic and terrestrial life. They are associated with diverse bioavailable geochemical fractions, like the water-soluble fraction and the exchangeable fraction, and non-available fractions like those associated with the crystalline net of clays and silica minerals. Depending upon their chemical and physical properties we can distinguish different mechanisms of metal toxicity in plants, such as production of reactive oxygen species from auto-oxidation, blocking and/or displacement of essential functional groups or metallic ions of biomolecules, changes in the permeability of cellular membranes, reactions of sulphydryl...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Decontamination; Heavy metals; Hyperaccumulation; Phytodegradation; Phytostabilization; Phytotoxicity.
Ano: 2007
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202007000200001

Alterations in biochemical components in mesta plants infected with yellow vein mosaic disease
Provedor de dados: 61
Autores: Chatterjee,Arpita; Ghosh,Subrata K.
Yellow vein mosaic disease of mesta (kenaf, Hibiscus cannabinus L.; and roselle, H. sabdariffa L.) is a new entrant to the disease scenario and it is associated with a novel monopartite Begomovirus. Changes in different biochemical parameters in diseased mesta plants were observed as compared to healthy ones. Isozyme pattern and assays of different enzymes, namely catalase, acid phosphatase, peroxidase, esterase, polyphenol oxidase and superoxide dismutase, revealed lower activities of catalase, acid phosphatase and peroxidase enzymes and enhanced activities of esterase, polyphenol oxidase and superoxide dismutase in diseased plants as compared to healthy ones. Due to the infection, chlorophyll content, phenolics and total soluble protein decreased whereas...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Begomovirus; Chlorophyll; Hibiscus; Isozyme pattern; Phenolics; Proline.
Ano: 2008
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202008000400002

Differential responses of ribulose-1,5-bisphosphate carboxylase/oxygenase activities of two Vigna unguiculata cultivars to salt stress
Provedor de dados: 61
Autores: Aragão,Maria Erivalda Farias de; Guedes,Marjorie Moreira; Otoch,Maria de Lourdes Oliveira; Guedes,Maria Izabel Florindo; Melo,Dirce Fernandes de; Lima,Maria da Guia Silva.
Vita 3 and Vita 5 are two Vigna unguiculata cultivars that differ in their capacities for survival in saline environments; Vita 3 is more tolerant and Vita 5 more sensitive. Both cultivars were submitted to salt stress with 0.1 M NaCl. After 8 days, root and shoot growth from both cultivars was reduced but reduction was more pronounced in Vita 5. Furthermore, leaf area was also reduced in this cultivar. Chlorophyll content and chlorophyll fluorescence parameters were not affected by salt stress, but the specific activities of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) decreased in Vita 3 and increased in Vita 5. The use of immunological techniques also revealed that the Rubisco content from Vita 3 decreased while that of Vita 5 increased....
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Rubisco; Photosynthesis; Salt stress; Vigna unguiculata.
Ano: 2005
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202005000200003

Growth and photosynthetic responses of Picea asperata seedlings to enhanced ultraviolet-B and to nitrogen supply
Provedor de dados: 61
Autores: Yao,Xiaoqin; Liu,Qing; Han,Chao.
Ultraviolet-B (UV-B) radiation and nitrogen are expected to increase simultaneously with future changes in global climate. In this study, growth and photosynthetic responses of Picea asperata seedlings to enhanced UV-B and to nitrogen supply were studied. The experimental design included two levels of UV-B treatments (ambient UV-B, 11.02 kJ m-2 d-1; enhanced UV-B, 14.33 kJ m-2 d-1) and two nitrogen levels (0; 20 g N m-2) to determine whether nitrogen can alleviate the negative impacts of enhanced UV-B on seedling growth and photosynthesis. Enhanced UV-B significantly inhibited plant growth and impaired net photosynthetic rate, stomatal conductance, transpiration rate, the light-saturated assimilation rate, assimilation capacity, light compensation point,...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Growth; Gas exchange; Nitrogen; Picea asperata; Photosynthesis; UV-B.
Ano: 2008
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202008000100002

Utility of basic research in plant/crop physiology in relation to crop improvement: a review and a personal account
Provedor de dados: 61
Autores: El-Sharkawy,Mabrouk A.
Agricultural research and development plays an essential role in a nation's economic development, providing for food security for an ever-increasing population. In developed countries, the gap between potential and actual yield is largely closed because of a combination of advanced technologies, high-yielding new varieties and the application of agrochemicals in highly mechanized production systems. In most of these countries, agricultural production exceeds national demand, resulting in excess products for export. In many of the developing countries, however, agricultural productivity is still far below what it should be because of multiple technical and socio-economic constraints. Food deficits are the norm in poor and middle-income countries, requiring...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Agriculture; Breeding; C4-photosynthesis; Drought-tolerance; Ecophysiology; Ecosystems; Hormones; Photoperiod; Productivity; Soil; Water stress.
Ano: 2006
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202006000400001

Nutritional adaptations of native plants of the cerrado biome in acid soils
Provedor de dados: 61
Autores: Haridasan,Mundayatan.
Soils of the cerrado biome, mostly oxisols and deep sandy entisols, are acid, dystrophic and poor in available nutrients. These soils are not very different from soils that occur in the Amazon region. However, the open savanna physiognomies of cerrado with lower biomass of their different components are deficient in nutrients at the ecosystem level, unlike the Amazon forests which retain high nutrient reserves in their live biomass. Field crops are susceptible to aluminum and manganese toxicities, besides nutrient deficiencies, in cerrado soils and do not grow well in the absence of liming and fertilization. However, concepts of nutrient deficiencies and toxicities, well established for cultivated plants, should not be extended to native species in natural...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Aluminum toxicity; Latosol; Mineral nutrition; Soil fertility.
Ano: 2008
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202008000300003

Mycorrhiza influence on maize development under Cd stress and P supply
Provedor de dados: 61
Autores: Andrade,Sara A. L. de; Silveira,Adriana P. D. da.
The role of arbuscular mycorrhizal fungi (AMF) on cadmium (Cd) accumulation and on the possible attenuation of Cd stress was studied in maize plants (Zea mays L. var. Exceller). Plants inoculated or not with Glomus macrocarpum were exposed to Cd (0-20 µmol L-1), at two P levels (5 and 10 mg L-1) in the nutrient solution. The experiment was conducted in a hydroponic system, using a randomized 2 x 2 x 2 factorial design. The mycorrhiza-Cd interaction on plant growth, nutrients and Cd accumulation, AMF root colonization and on extra-radical mycelium was investigated. Mycorrhiza promoted plant growth whereas Cd addition reduced plant biomass production. No difference in plant Cd concentrations was found between mycorrhizal (M) and non-mycorrhizal (NM) plants,...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Arbuscular mycorrhizal fungi; Cd distribution; Extra-radical mycelium; Heavy metals; Peroxidase; Phosphorus.
Ano: 2008
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202008000100005

The chlorophyll a fluorescence as an indicator of the temperature stress in the leaves of Prunus persica
Provedor de dados: 61
Autores: Martinazzo,Emanuela Garbin; Ramm,Aline; Bacarin,Marcos Antonio.
Plants growing in temperate regions are often exposed to stress conditions caused by high temperatures. Photosynthesis is one of the metabolic processes most sensitive to high temperature stress, and it is often inhibited before other cellular functions. Using peach leaf disks, we studied the transient chlorophyll a fluorescence along with the gas exchanges at temperatures of 25 (control) 30, 35, 40 and 45°C in the dark for a period of 30 minutes. Temperatures above 35°C caused significant changes in the transient fluorescence of chlorophyll a, including an increase in the initial fluorescence (F0), a decrease in maximum fluorescence values (F M) and the appearance of K and L bands. The values of the net assimilation rate decreased as the temperature...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: High temperature; Photosynthesis; Prunus persica.
Ano: 2012
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202012000400002

Lead toxicity in plants
Provedor de dados: 61
Autores: Sharma,Pallavi; Dubey,Rama Shanker.
Contamination of soils by heavy metals is of widespread occurrence as a result of human, agricultural and industrial activities. Among heavy metals, lead is a potential pollutant that readily accumulates in soils and sediments. Although lead is not an essential element for plants, it gets easily absorbed and accumulated in different plant parts. Uptake of Pb in plants is regulated by pH, particle size and cation exchange capacity of the soils as well as by root exudation and other physico-chemical parameters. Excess Pb causes a number of toxicity symptoms in plants e.g. stunted growth, chlorosis and blackening of root system. Pb inhibits photosynthesis, upsets mineral nutrition and water balance, changes hormonal status and affects membrane structure and...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Antioxidant defense system; Detoxification; Lead; Osmolytes; Toxicity; Phytochelatin; Phytoremediation; Rhizofiltration; Tolerance.
Ano: 2005
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202005000100004

Changes in the antioxidative enzyme activities and lipid peroxidation in wheat seedlings exposed to cadmium and lead stress
Provedor de dados: 61
Autores: Dey,Surjendu K.; Dey,Jayashree; Patra,Sanjukta; Pothal,Debasmita.
Wheat seedlings were grown in presence of CdCl2 (0-200 µM) and Pb(NO3)2 (0-2000 µM) separately. The growth of metal-treated seedlings was significantly depressed. The activities of antioxidative enzymes namely superoxide dismutase (SOD), catalase (CAT) and guaiacol peroxidase (POX) were altered both in root and shoot tissues of 7-d-old seedlings. Under Cd stress, SOD activity in roots was undetectable even at the lowest Cd concentration (50 µM) whereas in shoots it declined sharply with increasing Cd levels. The activity of CAT declined to a greater extent in roots than in shoots. Even though the POX activity increased nine times in shoots, a decreasing trend was observed in root tissues due to Cd stress. Under Pb stress, the induction in SOD activity and...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Catalase; Heavy metals; Peroxidase; Superoxide dismutase; Triticum.
Ano: 2007
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202007000100006

Yield and composition of the essential oil of Mentha piperita L. (Lamiaceae) grown with biosolid
Provedor de dados: 61
Autores: Scavroni,Joseane; Boaro,Carmen Sílvia Fernandes; Marques,Márcia Ortiz Mayo; Ferreira,Leonardo Cesar.
This research evaluated the effects of biosolid levels on yield and chemical composition of Mentha piperita L. essential oil. Mint plants were grown in a greenhouse in pots containing the equivalent to 0, 28, 56, and 112 t.ha-1 biosolid. Three evaluations were made at 90, 110, and 120 days after planting (DAP). The oil was extracted from the dry matter of shoots by hydrodistillation, and composition was determined by GC/MS. Oil production was slightly affected by the biosolid, increasing when plants were grown with 28 t.ha-1, a condition which did not result in quality improvement. Menthyl acetate was the component obtained at the highest percentage in all treatments. At 90 DAP, plants showed a higher percentage of menthol, the second-highest oil...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Menthol; Menthyl acetate; Peppermint; Sewage-sludge.
Ano: 2005
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202005000400002

Foliar application of Burkholderia sp. strain TNAU-1 leads to activation of defense responses in chilli (Capsicum annuum L.)
Provedor de dados: 61
Autores: Madhavan,Srinivasan; Paranidharan,Vaikuntavasan; Velazhahan,Rethinasam.
Induction of phenolics, peroxidase (PO), polyphenol oxidase (PPO), chitinase and thaumatin-like proteins (TLP) in leaves of chilli (Capsicum annuum L.) in response to foliar application with a biocontrol agent Burkholderia sp. strain TNAU-1 was studied. Chilli plants, when sprayed with Burkholderia sp. strain TNAU-1 showed increase in phenolic content one day after application and the maximum accumulation was observed seven days after treatment. Three new peroxidase isozymes (PO-1, PO-2 and PO-3) were induced in chilli leaves upon treatment with Burkholderia sp. strain TNAU-1. The activity of all the peroxidases was at the maximum level three days after treatment and subsequently decreased. Protein extracts obtained from Burkholderia sp. strain TNAU-1...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Capsicum annuum; Chitinase; Induced resistance; Peroxidase; Phenolics; Polyphenol oxidase; Thaumatin-like protein.
Ano: 2011
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202011000400003

Purification and characterization of cytosolic and cell wall β-galactosidases from Vigna unguiculata stems
Provedor de dados: 61
Autores: Sudério,Fabrício Bonfim; Barbosa,Gislainy Karla da Costa; Gomes-Filho,Enéas; Enéas-Filho,Joaquim.
Three β-galactosidase isoforms, β-gal I and β-gal II (cytosolic) and β-gal III (cell wall-associated), were isolated from stems of Vigna unguiculata (L.) Walp. cv. Pitiúba seedlings. Purification consisted of aμMonia sulfate fractionation followed by chromatography in DEAE-Sephadex and Lactosyl-Sepharose columns. The two cytosolic isoforms showed the same chromatography pattern, which differed from that of β-gal III. Electrophoresis revealed a single band of protein for β-gal II and β-gal III which also expressed β-galactosidase activity in gel. The apparent molecular mass of the β-gal I, II and III was 89, 146 and 124 kDa, respectively. The three isoforms revealed the same optimal pH (4.0) and the same optimal assay temperature (55ºC) for enzyme activity....
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Enzymatic kinetics; Cowpea; Optimal pH; Enzyme purification; Thermal stability; Thermal inactivation.
Ano: 2011
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202011000100003

Photoacclimation in three species of freshwater red algae
Provedor de dados: 61
Autores: Bautista,Anna I.N.; Necchi Jr.,Orlando.
Three freshwater Rhodophyta species (Audouinella eugenea, A. hermannii and Compsopogon coeruleus) were tested as to their responses (photosynthesis, growth and pigment concentration) to two irradiances (low light, LL, 65 µmol m-2 s-1 and high light, HL, 300 µmol m-2 s-1) and two periods (short time, ST, 4 d, and long time, LT, 28 d). Higher growth rates were consistently observed at LL but significant differences were observed only for A. hermannii. Higher values of photoinhibition at LL were found for the three species, which is consistent with the dynamic photoinhibition as a reversible photoprotective mechanism against high irradiance. Light-induced decreases of effective quantum yield (EQY) were observed in the three species consisting of pronounced...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Chlorophyll fluorescence; Growth; Irradiance; Photosynthesis; Pigment; Red algae.
Ano: 2007
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202007000100003

Interactive effects between supplemental ultraviolet-B radiation and heavy metals on the growth and biochemical characteristics of Spinacia oleracea L.
Provedor de dados: 61
Autores: Shweta,Mishra; Agrawal,S.B.
The impact of supplemental UV-B (sUV-B) radiation and heavy metals: Cd (68 µmol.kg-1 soil) and Ni (68 µmol.kg-1 soil) singly and in combination was studied on photosynthetic and non-photosynthetic pigments, metabolites, enzyme activities, biomass accumulation and the net primary productivity of spinach (Spinacia oleracea L. var. All Green), a common leafy vegetable plant. Both the stresses individually and in combination resulted in the reduction of photosynthetic pigments, ascorbic acid, and catalase activity, whereas a reverse trend was observed for anthocyanin, flavonoids and proline content, lipid peroxidation and peroxidase activity. The interactive effects of both the stresses were, however, less than additive. Combined treatment of sUV-B + Cd was...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Spinaicia oleracea; Biomass; Cadmium; Enzymes; Nickel; Pigments; Ultraviolet-B.
Ano: 2006
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202006000200007

Isolation and in silico characterization of cDNA encoding cyclophilin from etiolated Vigna mungo seedlings
Provedor de dados: 61
Autores: Kuhar,Kalika; Gupta,Varun Kumar; Kansal,Rekha; Gupta,Vijay Kumar.
A full-length cDNA clone encoding cyclophilin gene of 848 bp, including a 519 bp open reading frame, has been isolated from the cDNA library constructed from etiolated seedlings of Vigna mungo (GenBank FN668732). The cDNA sequence showed 97% identity with Vigna radiata cyclophilin mRNA. The sequence was GC rich and lacked introns. The open reading frame encoded 172 amino acid polypeptide with molecular weight 18.3 kDa and theoretical pI 8.61. BlastP analysis indicated that its putative amino acid sequence shared 100% identity with several plant cyclophilins particularly legumes. The conserved seven amino acid residues region in V. mungo cyclophilin was RSGKPLH (present in legumes) instead of KSGKPLH, indicating its similarity to the cyclophilins of other...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Gene library; Open reading frame.
Ano: 2012
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202012000100009

Pretreatment with H2O2 in maize seeds: effects on germination and seedling acclimation to salt stress
Provedor de dados: 61
Autores: Gondim,Franklin A; Gomes-Filho,Enéas; Lacerda,Claudivan F; Prisco,José Tarquinio; Azevedo Neto,André D; Marques,Elton C.
The aim of this study was to evaluate the effects of H2O2 on germination and acclimation of maize plants subject to salt stress. Three experiments using BRS3003 seeds, a triple hybrid of maize, were carried out in a growth room and in greenhouse. In the first experiment, H2O2 accelerated the germination percentage of seeds at 100 mM, but not at 500 mM. In the second experiment, the pretreatment of seeds was observed to induce a pronounced increase in ascorbate peroxidase (APX) and catalase (CAT) enzyme activity after 30 h of soaking in H2O2. It was also observed that guaiacol peroxidase (GPX) activity was smaller in the seeds soaked in H2O2 for 12, 24, 30, 36 and 42 h, in relation to those soaked in distilled water. The superoxide dismutase (SOD) activity...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Antioxidant enzymes; Hydrogen peroxide; Oxidative stress; Salinity stress; Zea mays.
Ano: 2010
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202010000200004

Lysine catabolism: flow, metabolic role and regulation
Provedor de dados: 61
Autores: Fornazier,Ricardo Francisco; Azevedo,Ricardo Antunes; Ferreira,Renato Rodrigues; Varisi,Vanderlei Aparecido.
Lysine is an essential amino acid, synthesized in plants in the aspartic acid pathway. The lysine catabolism is performed by the action of two consecutive enzymes, lysine 2-oxoglutarate reductase (LOR) and saccharopine dehydrogenase (SDH). The steady state of lysine is controlled by both, synthesis and catabolism rates, with the final soluble lysine concentration in cereal seeds a direct result of these processes. In the last 40 years, the enzymes involved in lysine biosynthesis have been purified and characterized from some plant species such as carrot, maize, barley, rice, and coix. Recent reports have revealed that lysine degradation might be related to various physiological processes, for instance growth, development and response to environmental...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Amino acids; Lysine; Metabolism; Mutants.
Ano: 2003
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202003000100002

Growth regulators and essential oil production
Provedor de dados: 61
Autores: Prins,Cláudia L; Vieira,Ivo J. C; Freitas,Silvério P.
The aroma and fragrance industry is a billion-dollar world market which grows annually. Essential oils comprise the majority of compounds used by these industries. These sets of metabolites are formed mainly by monoterpenes, which are products of the plants' secondary metabolism. Biosynthesized from mevalonate and methylerythitol phosphate, the essential oil production depends not only on genetic factors and the developmental stage of plants, but also on environmental factors which could result in biochemical and physiological alterations in plants modifying the quantity and quality of the essential oil. These modifications impair aromatic plant production aimed at essential oil by reducing their quality. It is desirable to develop techniques of...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Auxins; Cytokinins; Gibberellins; Ethylene; Jasmonate; Terpenoids.
Ano: 2010
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202010000200003

The influence of processing and long-term storage on the antioxidant metabolism of acerola (Malpighia emarginata) purée
Provedor de dados: 61
Autores: Oliveira,Luciana S.; Rufino,Maria S. M.; Moura,Carlos F. H.; Cavalcanti,Fabio R.; Alves,Ricardo E.; Miranda,Maria R. A.
This study evaluated the effect of the processing and long-term storage on the antioxidant potential and activity of antioxidant enzymes of frozen purées from six acerola clones. Ripe acerolas from clones BRS 235, BRS 236, BRS 237, BRS 238, II47/1 and BRS 152 were harvested; the pulp was processed, packed in sealed polyethylene plastic bags and stored in a domestic freezer at -18°C for 11 months. Samples of each clone were analyzed on harvest/processing day and every 30 days after for bioactive antioxidant compounds, antioxidant enzyme activity and total antioxidant activity. Acerola purées presented a decrease of non-enzyme antioxidants and an increase of antioxidant enzymes activities, indicatives of a compensatory mechanism between enzymatic and...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Pulp; Enzymes; Vitamin C; Postharvest; Frozen.
Ano: 2011
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202011000200007

Inhibition of the water splitting system by sodium chloride stress in the green alga Chlorella vulgari
Provedor de dados: 61
Autores: EL-Sheekh,Mostafa M.
The effect of sodium chloride on the photosynthetic electron transport chain was investigated in the freshwater green alga Chlorella vulgaris. It was found that the rate of oxygen evolution under steady state and flash light conditions diminished by increasing salt concentrations. Salt treatment of cells also decreased the fluorescence and delayed luminescence yields. However, the fluorescence yield was almost completely restored by the addition of an artificial electron donor to the NaCl-treated cells. The oscillation pattern of the thermoluminescence B band as a function of flash number indicated that the S2&lt;FONT FACE=Symbol&gt;®&lt;/FONT&gt;S3 transition of the water splitting system is inhibited by NaCl treatment.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Chlorella; Electron transport; Photosystem II; Salinity.
Ano: 2004
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202004000100004

Extraction and determination of ascorbate and dehydroascorbate from apoplastic fluid of stem of rooted and non-rooted cuttings in relation to the rhizogenesis
Provedor de dados: 61
Autores: Zuffellato-Ribas,Katia Christina; Morini,Stefano; Picciarelli,Piero; Mignolli,Francesco.
Starting from semihardwood branches of peach and plum rootstocks (Prunus cerasifera E.) cv. MRS2/5, plum rootstocks (Prunus cerasifera × P. salicina) × (P. cerasifera × P. persica) cv. Ishtarà and olive tree (Olea europaea L.) cv. Frantoio, cuttings were collected and treated with 0 mg.L-1 and 2500 mg.L-1 of indolebutyric acid (IBA) by immersion in the base of the cuttings. After 60 days of planting, the cultivars MRS 2/5, Ishtarà and Frantoio presented a significative difference with relation to the rooting induction by application of the indolebutyric acid (27.5, 47.5 and 41.25 %, respectively), inducing a higher number of roots per cutting without at the same time significantly increasing the length of the roots themselves. The levels of ascorbate and...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Olive tree; Peach rootstock; Plum rootstock; Redox potential; Rooting.
Ano: 2010
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202010000200006

Cell wall hydrolases in the seeds of Euphorbia heterophylla L. during germination and early seedling development
Provedor de dados: 61
Autores: Suda,Cecilia N. K.; Buckeridge,Marcos S.; Giorgini,Jarbas F.
Activities of cell wall hydrolases of Euphorbia heterophylla L. (wild poinsettia) endosperm were investigated during pre- and post-emergence periods, defined as the time interval before and after 2.2 days from the start of imbibition, respectively. The activities of endo-beta-mannanase and beta-mannosidase are higher over the pre-emergence when compared to the post-emergence period and they may be involved in the process of germination in E. heterophylla. On the other hand, the activities of beta-galactosidase, beta-glucosidase, alpha-xylosidase, beta-xylosidase and glucanases, which hydrolyse CMC, xyloglucans from Hymenaea courbaril or Copaifera langsdorffii, xylan, Avicel and lichenan, are higher over the post-emergence period. Activity on laminarin...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Cotyledon expansion; Endosperm; Endoglucanase; Endomannanase; Euphorbiaceae; Xylanase.
Ano: 2003
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202003000300002

Ecophysiology of tropical tree crops: an introduction
Provedor de dados: 61
Autores: DaMatta,Fábio M.
In this special issue, ecophysiology of major tropical tree crops, considered here on a broader sense and including species such as banana, cashew, cassava, citrus, cocoa, coconut, coffee, mango, papaya, rubber, and tea, are examined. For most of these crops, photosynthesis is treated as a central process affecting growth and crop performance. The crop physiological responses to environmental factors such as water availability and temperature are highlighted. Several gaps in our database concerning ecophysiology of tropical tree crops are indicated, major advances are examined, and needs of further researches are delineated.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Crop growth and production; Environmental stresses and physiology; Photosynthesis; Gas exchange; Tropical tree crops.
Ano: 2007
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202007000400001

Some thoughts on the physiology of caffeine in coffee: and a glimpse of metabolite profiling
Provedor de dados: 61
Autores: Baumann,Thomas W.
Human beings enjoy the flavor and stimulating activity of a cup of coffee without knowing that by doing so, they are part of a 'food web' and receive signals coffee plants build to improve their struggle for life. This review is centered in the first part on the purine alkaloid caffeine and its physiological role in the coffee plant's life cycle. Many of the thoughts and ideas presented here are plain speculation, because the real research revealing the secrets of plant physiology such as e.g. the formation of the coffee bean with all its ingredients, has just started. The recent achievements in molecular biology made it possible to tackle and answer new questions regarding the regulation of secondary metabolism in the coffee plant organs at selected...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Endosperm; Flower; Germination; Metabolite profiling; Purine alkaloid; Perisperm.
Ano: 2006
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202006000100017

Physiological parameters in sugarcane cultivars submitted to water deficit
Provedor de dados: 61
Autores: Graça,José Perez da; Rodrigues,Fabiana Aparecida; Farias,José Renato Bouças; Oliveira,Maria Cristina Neves de; Hoffmann-Campo,Clara Beatriz; Zingaretti,Sonia Marli.
To investigate the processes involved in the susceptibility of sugarcane plants to water deficit, several physiological parameters were evaluated in drought tolerant (SP83-2847 and CTC15) and sensitive (SP86-155) cultivars. The water deficit affected the photosynthetic apparatus of all the plants in different ways, within and among cultivars. The photosynthetic rate and stomatal conductance decreased significantly in all cultivars submitted to water deficit. In control plants of the tolerant cultivars (SP83-2847 and CTC15) the photosynthetic rate was higher than in the sensitive cultivar (SP86-155). Cultivar CTC15 showed the highest relative water content during the dry period. The quantum efficiency photosystem II of cultivar SP83-2847 was more stable in...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Photosynthetic efficiency; Relative water content; Saccharum; Water stress; Drought.
Ano: 2010
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202010000300006

Anatomical characteristics and enzymes of the sucrose metabolism and their relationship with latex yield in the rubber tree (Hevea brasiliensis Muell. Arg.)
Provedor de dados: 61
Autores: Mesquita,Alessandro Carlos; Oliveira,Luiz Edson Mota de; Mazzafera,Paulo; Delú-Filho,Nelson.
Rubber production is dependent on the availability of carbohydrates in the tissues engaged in latex synthesis. In this study three rubber tree clones were used to study the protein profile, the activities of invertase and sucrose synthase in the latex and anatomical characteristics of the bark, as well as to establish a possible relationship with latex production. The clones used in the study, RRIM 600, GT 1 and Fx2261, differed in latex productivity, from high to low in this order. Although present, few differences were observed in the latex protein profile obtained by denaturing electrophoresis. The activity of neutral invertase was higher than the acidic isoform, and both activities were higher in the most productive clones RRIM 600 and GT 1. The same...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Hevea brasiliensis; Invertase; Lacticiferous vessels; Latex; Rubber; Sucrose synthase.
Ano: 2006
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202006000200002

Cloning and sequence analysis of tomato cpDNA fragments: towards developing homologous chloroplast transformation vectors
Provedor de dados: 61
Autores: Berger,Irving Joseph; Carraro,Dirce Maria; Bock,Ralph; Azevedo,Ricardo Antunes; Carrer,Helaine.
With the view of developing chloroplast transformation vectors based on homologous targeting regions for tomato (Lycopersicon esculentum L.), plastid DNA fragments of tomato cv. IAC-Santa Clara were cloned and analyzed. Isolation and cloning of PstI/SalI chloroplast fragments into the pBlueScript vectors yielded the plasmids pIJB1 and pIJB2 with cpDNA fragments of 8.6 kb and 6.4 kb, respectively. DNA sequencing and computer analyses revealed that the tomato sequences cloned display from 93 to 100 % of identity to the respective fragments in tobacco, which is more pronounced in coding regions. The intergenic spacers are somewhat less conserved suggesting that evolutionary divergences occurred mainly in these putative non-coding regions. The most remarkable...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Lycopersicon esculentum; Nicotiana tabacum; Chloroplast DNA; Plastid transformation; Plastome; Tobacco; Tomato.
Ano: 2005
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202005000200007

Some aspects of citrus ecophysiology in subtropical climates: re-visiting photosynthesis under natural conditions
Provedor de dados: 61
Autores: Ribeiro,Rafael V.; Machado,Eduardo C.
In this review we re-visit and discuss the current knowledge on ecophysiology of citrus trees, addressing the influence of environmental conditions on citrus photosynthesis. Knowledge of physiological responses of citrus trees to their surrounding environment is essential in order to improve crop production and plant development, both being consequences of appropriate horticultural management in citrus orchards. In this context, citrus photosynthesis is addressed as the primary source of carbon and energy for plant growth and development. The photosynthetic activity on both a daily and a seasonal scale is reviewed, taking into consideration the physiological aspects related to seasonal variation of photochemical and biochemical activities, stomatal...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Carbohydrate; Citrus; Chlorophyll fluorescence; Gas exchange; Seasonality.
Ano: 2007
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202007000400009

Secrets in secretions: genes that control nematode parasitism of plants
Provedor de dados: 61
Autores: Hussey,Richard S.; Davis,Eric L.; Baum,Thomas J.
The most evolutionary advanced adaptations for plant parasitism by nematodes are the products of parasitism genes expressed in their esophageal gland cells and secreted through their stylet into host tissue to control the complex process of parasitism. Molecular analyses of nematode parasitism genes are revealing the complexity of the tools a nematode possesses that enable it to attack plants and paints a more elaborate picture of host cellular events under specific control by the parasite than previously hypothesized. Interestingly, the majority of the nematode parasitism genes discovered encodes proteins unique to plant parasites. Identifying the complete profile of parasitism genes expressed throughout the parasitic cycle of a nematode is the key to...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Esophageal gland cells; Nematode parasitism; Parasitome; Parasitism genes; Secretion.
Ano: 2002
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202002000300002

Indole-3-acetic acid metabolism in normal and dwarf micropropagated banana plants (Musa spp. AAA)
Provedor de dados: 61
Autores: Zaffari,Gilmar Roberto; Peres,Lázaro Eustáquio Pereira; Tcacenco,Fernando Adami; Kerbauy,Gilberto Barbante.
Nanism is one of the most frequent type of mutant in micropropagated banana plants from the Cavendish subgroup. The present study aimed at studying some of the hormone factors involved in this type of mutation. Rhizomes from normal and dwarf plants from the cultivar Grand Naine were incubated for 5 d in the presence of [³H]-L-tryptophan, [³H]-indole-3-acetic acid and gibberellin, to quantify the endogenous levels of indole-3-acetic acid-ester, indole-3-acetic acid-amide, free indole-3-acetic acid, and cytokinins. The endogenous levels of indole-3-acetic acid and its ester- and amide-conjugated forms were measured in normal and dwarf plants incubated for 30 d with gibberellin, indole-3-acetic acid, and L- and D-tryptophan. In normal plants, the use of...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Indole-3-acetic acid metabolism; Growth regulators; Somaclonal variation.
Ano: 2002
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202002000300005

Coffee resistance to the main diseases: leaf rust and coffee berry disease
Provedor de dados: 61
Autores: Silva,Maria do Céu; Várzea,Victor; Guerra-Guimarães,Leonor; Azinheira,Helena Gil; Fernandez,Diana; Petitot,Anne-Sophie; Bertrand,Benoit; Lashermes,Philippe; Nicole,Michel.
Considerable success has been obtained in the use of classical breeding to control economically important plant diseases, such as the coffee leaf rust and the coffee berry disease (CBD). There is a strong consensus that growing genetically resistant varieties is the most appropriate cost effective means of managing plant diseases and is one of the key components of crop improvement. It has also been recognized that a better knowledge of both, the pathogens and the plant defence mechanisms will allow the development of novel approaches to enhance the durability of resistance. After a brief description of concepts in the field of plant disease resistance, we attempt to give a view of the research progress on coffee leaf rust and CBD concerned with the...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Coffea; Colletotrichum kahawae; Hemileia vastatrix; Coffee breeding; Resistance.
Ano: 2006
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202006000100010

Physiology of citrus fruiting
Provedor de dados: 61
Autores: Iglesias,Domingo J.; Cercós,Manuel; Colmenero-Flores,José M.; Naranjo,Miguel A.; Ríos,Gabino; Carrera,Esther; Ruiz-Rivero,Omar; Lliso,Ignacio; Morillon,Raphael; Tadeo,Francisco R.; Talon,Manuel.
Citrus is the main fruit tree crop in the world and therefore has a tremendous economical, social and cultural impact in our society. In recent years, our knowledge on plant reproductive biology has increased considerably mostly because of the work developed in model plants. However, the information generated in these species cannot always be applied to citrus, predominantly because citrus is a perennial tree crop that exhibits a very peculiar and unusual reproductive biology. Regulation of fruit growth and development in citrus is an intricate phenomenon depending upon many internal and external factors that may operate both sequentially and simultaneously. The elements and mechanisms whereby endogenous and environmental stimuli affect fruit growth are...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Abiotic stresses; Abscission; Color break; Flowering; Fruit set; Ripening.
Ano: 2007
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202007000400006

Isolation and characterization of novel lectins from Canavalia ensiformis DC and Dioclea grandiflora Mart. ex Benth. seeds
Provedor de dados: 61
Autores: Melgarejo,Luz Marina; Vega,Nohora; Pérez,Gerardo.
Two lectins were isolated from Canavalia ensiformis and Dioclea grandiflora seeds. Gel filtration produced a fraction corresponding to Con A or D. grandiflora lectin while erythroagglutination assays revealed a distinct fraction presenting a lectin that agglutinates human red blood cells (RBCs) but not rabbit RBCs. Hydrophobic interaction chromatography showed that the latter fraction yielded a protein that readily agglutinates human erythrocytes; the lectin was also purified by affinity chromatography on Lac-Sepharose showing similar properties to that of the Phenyl-Sepharose-purified lectin. Despite minor differences (carbohydrate content or A1%1cm), the two lectins showed similar molecular properties in that they consisted of two non-covalently linked...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Diocleinae; Leguminoseae; Characterization; Lectins.
Ano: 2005
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202005000300006

Phenolic compounds in coffee
Provedor de dados: 61
Autores: Farah,Adriana; Donangelo,Carmen Marino.
Phenolic compounds are secondary metabolites generally involved in plant adaptation to environmental stress conditions. Chlorogenic acids (CGA) and related compounds are the main components of the phenolic fraction of green coffee beans, reaching levels up to 14 % (dry matter basis). These compounds have a number of beneficial health properties related to their potent antioxidant activity as well as hepatoprotective, hypoglycemic and antiviral activities. The main groups of CGA found in green coffee beans include caffeoylquinic acids, dicaffeoylquinic acids, feruloylquinic acids, p-coumaroylquinic acids and mixed diesters of caffeic and ferulic acids with quinic acid, each group with at least three isomers. During coffee processing, CGA may be isomerized,...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Coffea; Chlorogenic acids; Chlorogenic acid lactones; Coffee quality; Coffee processing; Coffee roasting; Quinides.
Ano: 2006
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202006000100003

Caracterização de ER49, um fator de elongação da síntese de proteínas do tipo Ts, expresso durante a maturação do fruto de tomate
Provedor de dados: 61
Autores: Chaves,Ana Lúcia S.; Silva,J.A.; Pech,J.-C.; Latche,A.; Bouzayen,M.; Zegzouti,H.; Rombaldi,Cesar V.
O etileno, conhecido, sobretudo, como o fitormônio da maturação de frutos, está envolvido em vários processos fisiológicos, atuando na regulação da expressão de grande número de genes. O clone parcial de cDNA ER49 foi previamente isolado mediante a técnica do "Differential Display". A obtenção e a análise da seqüência completa confirmaram as homologias significativas com fatores de elongação da síntese de proteínas do tipo Ts. Tais proteínas são responsáveis pela reciclagem do complexo EF-Tu•GDP, que atua na ligação do aminoacil-RNAt ao ribossomo. A predição da seqüência protéica permitiu a detecção de um peptídio sinal de endereçamento para a mitocôndria e dos domínios TS-N e EF-Ts. A modelagem da estrutura terciária mostrou que ER49 poderia interagir com...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: EF-Ts; Etileno; Frutos climatéricos; Lycopersicon esculentum; Regulação pós-transcricional.
Ano: 2002
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202002000100003

Ecophysiological studies of two andean forest contrasting species Abatia parviflora and Myrcianthes leucoxyla under Bogotá conditions, Colombia
Provedor de dados: 61
Autores: Colmenares-Trejos,Sara L.; Melgarejo,Luz Marina; Romero A.,Hernán Mauricio.
The physiological response of high Andean forest contrasting plants, Myrcianthes leucoxyla, a shadow-facultative heliophyte, and Abatia parviflora, a heliophyte, was studied during the transition from dry season to wet season in Bogotá. Light response curves (A-PAR), water potential (Ψw), transpiration rate (E), stomatal conductance (gs), leaf soluble protein content and peroxidase activity were measured in this study in a 48h cycle. The values for E, gs, Ψw and Ψw predawn for M. leucoxyla were 0.07 to 4.89 µg/cm s, 0.02 to 0.5 cm s-1, -0.025 to -1.05 MPa, and-0.1 MPa, respectively. For A. parviflora E, gs, Ψw and Ψw predawn were 0.47 to 12.27 µg/cm s, 0.17 to 1.42 cm s-1, -0.05 to -0.3 MPa and -0.075 MPa, respectively. A. parviflora presented a tendency...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: A-PAR curves; Gas exchange; Heliophyte; Shadow plant; Water potential.
Ano: 2011
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202011000400008

Gas exchanges and carbohydrate metabolism in orangetrees with citrus variegated chlorosis
Provedor de dados: 61
Autores: Gomes,Mara de Menezes de Assis; Lagôa,Ana Maria Magalhães Andrade; Machado,Eduardo Caruso; Medina,Camilo Lázaro; Machado,Marcos Antônio.
Gas exchanges, sucrose, starch and reducing sugar contents were analyzed in leaves of orange trees with and without Citrus Variegated Chlorosis (CVC), a disease caused by the bacteria Xylella fastidiosa. Healthy plants (HP) and diseased plants (DP) were evaluated 20 and 26 months after bacterial inoculation, in October 1998 and April 1999, respectively. On the first evaluation date, CO2 assimilation rates for HP were greater than DP in the early morning and midday, but on the second date they were greater in HP all along the day. On the first date, there was an increase in the sucrose content of DP at 15:00 h and 17:00 h in relation to HP. On the second evaluation date, DP presented greater reducing sugar content only in the early morning while sucrose...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Citrus sinensis L.; Photosynthesis; Reducing sugars; Starch; Sucrose; Xylella fastidiosa.
Ano: 2003
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202003000100004

Effects of hypoxia storage on gene transcript accumulation during tomato fruit ripening
Provedor de dados: 61
Autores: Pegoraro,Camila; Santos,Railson Schreinert dos; Krüger,Mariana Madruga; Tiecher,Aline; Maia,Luciano Carlos da; Rombaldi,Cesar Valmor; Oliveira,Antonio Costa de.
Tomato (Solanum lycopersicum L.) is a climacteric fruit, i.e., during ripening an increase in ethylene synthesis and high rate of respiration are observed. Low oxygen levels might inhibit or block ethylene biosynthesis and therefore retard the ripening process. Despite commercial applications of low oxygen treatments, the precise mode of action of low oxygen in fruit tissues and ripening is not well understood. In order to delineate the molecular responses to low oxygen stress in fruits, hypoxia-responsive tomato genes encoding heat shock factors, heat shock proteins, and enzymes involved in fermentation and ethylene synthesis pathways were analyzed. In this study, tomato fruit stored under hypoxia conditions showed that HSP17.7 and HSP21 genes were highly...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Gene expression; Heat shock proteins; Solanum lycopersicum.
Ano: 2012
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202012000200007

24-epibrassinolide regulated diminution of Cr metal toxicity in Brassica juncea L. plants
Provedor de dados: 61
Autores: Arora,Priya; Bhardwaj,Renu; Kanwar,Mukesh Kumar.
The present work was undertaken to study the effects of 24-epibrassinolide (0, 10-10, 10-8 and 10-6 M) on growth (shoot length and number of leaves), protein content and activities of antioxidative enzymes [guaiacol peroxidase (EC 1.11.1.7), catalase (EC 1.11.1.6), glutathione reductase (EC 1.6.4.2), ascorbate peroxidase (EC 1.11.1.11), superoxide dismutase (EC 1.15.1.1), monodehydroascorbate reductase (EC 1.1.5.4) and dehydroascorbate reductase (EC 1.8.5.1)] in leaves of 60 days-old Brassica juncea L. plants treated with different concentrations of Cr metal. It was observed that treatment of different concentrations (0, 0.5, 1.0, 1.5 and 2.0 mM) of Cr metal alone decreased the shoot length and number of leaves and regulated the enzyme activities and...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Antioxidative enzymes; Brassinosteroids; Metal toxicity.
Ano: 2010
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202010000300002

II. Heat stress in Triticum: kinetics of Cu and Zn accumulation
Provedor de dados: 61
Autores: Dias,Ana S.; Lidon,Fernando C.
The interactions between high temperatures and Cu/Zn accumulation were investigated in bread and durum wheat. Plants were grown in a greenhouse, at two different temperatures regimes (control - 25/14ºC and heat stress - 31/20ºC), and the contents and uptake/translocation of Cu and Zn were evaluated during three developmental stages of plant growth (booting, grain filling and maturity). During grain filling and at maturity it was found that root, shoot and spike concentrations of Cu increased in heat stressed plants of the genotypes Golia and Acalou. The same trend was observed for root and shoot concentrations of Zn in both durum wheat genotypes. It was concluded that plants submitted to high temperatures (during the grain filling period) become more...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Triticum aestivum L.; Triticum turgidum subsp; Durum; Heat stress; Uptake; Nutrients translocation.
Ano: 2009
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202009000200006

Thinning with NAA, NAD, ethephon, urea and by hand to improve fruit quality of 'Gerdi' apricot
Provedor de dados: 61
Autores: Taghipour,Leila; Rahemi,Majid; Assar,Pedram.
This research was conducted to study the effects of chemical and hand thinning on fruit quality of 'Gerdi' apricot. In the first year, three weeks after full bloom (AFB) branches of mature trees were sprayed with naphthalene acetic acid (NAA) at 10, 20, and 40 mg L-1, naphthalene acetamide (NAD) at 20, 40, and 80 mg L-1, ethephon at 50, 100 and 200 mg L-1, or urea at 0.2, 0.4, and 0.6%. In next year, hand thinning was performed as a separate experiment and leaf to fruit ratio (LFR) was adjusted to 10:1, 20:1 or 30:1 at pit-hardening stage of fruit development. In both years, NAA at 40 mg L-1, NAD at 80 mg L-1 and all concentrations of ethephon significantly increased fruit drop. All concentrations of urea significantly increased fruit drop in 2006, but...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Chemical thinning; Fruit characteristics; Prunus armeniaca; Total soluble solids.
Ano: 2011
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202011000400005

Water relations and some aspects of leaf metabolism of Jatropha curcas young plants under two water deficit levels and recovery
Provedor de dados: 61
Autores: Arcoverde,Gabriela B.; Rodrigues,Bruno M.; Pompelli,Marcelo F.; Santos,Mauro G.
Stomatal conductance (g s), transpiration (E), relative water content (RWC), superoxide dismutase activity (SOD), malondialdehyde (MDA), leaf carbohydrate soluble (LCS), free amino acids (FAA) and total protein (TP) content were measured under mild and severe drought stress in young potted Jatropha curcas L. in the greenhouse. The plants were kept for 12 days under three different water regimes, control (well hydrated), 50% irrigation control (mild stress) and 25% (severe stress), after rehydration were measured on the second and fourth day. Both mild and severe stress decreased g s and E; however, only severe stress reduced LCS, FAA and TP content and increased SOD activity (70%) and MDA content (60%) compared with the control. Moreover, under these...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Biodiesel; Drought tolerance; MDA; Oxidative stress; ROS; Water deficit.
Ano: 2011
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202011000200004

The architecture of Phaseolus vulgaris root is altered when a defense response is elicited by an oligogalacturonide
Provedor de dados: 61
Autores: Mata,Georgina Hernández; Sepúlveda,Baldemar; Richards,Alan; Soriano,Eva.
Phytoalexin accumulation is one of a myriad of plant defense responses; these responses can be elicited by pathogens or molecules such as oligogalacturonides (OGAs). Phytoalexin production has been considered a vital component of the resistance mechanisms that determine the outcome of many plant-microbe interactions. Besides inducing defense responses, OGAs have been shown to affect plant development, which normally is controlled by plant hormones, particularly auxin. In this work we measured phytoalexin accumulation in roots of bean (Phaseolus vulgaris L.) seedlings grown in the presence or absence of the auxin 3-naphtalenacetic acid (NAA) and treated with a decagalacturonide (OGA10). We found that OGA10 (0.01 mM) caused phytoalexin production and also...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Auxin; Phytoalexin; Phaseolus vulgaris; Root.
Ano: 2006
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202006000200012

Genetics of coffee quality
Provedor de dados: 61
Autores: Leroy,Thierry; Ribeyre,Fabienne; Bertrand,Benóit; Charmetant,Pierre; Dufour,Magali; Montagnon,Christophe; Marraccini,Pierre; Pot,David.
Coffee quality, in the present context of overproduction worldwide, has to be considered as a main selection criterion for coffee improvement. After a definition of quality, and an overview of the non genetic factors affecting its variation, this review focuses on the genetic factors involved in the control of coffee quality variation. Regarding the complexity of this trait, the different types of quality are first presented. Then, the great variation within and between coffee species is underlined, mainly for biochemical compounds related to quality (caffeine, sugars, chlorogenic acids, lipids). The ways for breeding quality traits for cultivated species, Coffea arabica and Coffea canephora are discussed, with specific challenges for each species. For C....
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Coffea spp.; Biochemical compounds; Candidate genes; ESTs; Genetic breeding; Marker-assisted selection; Quality.
Ano: 2006
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202006000100016

Ripening and quality of 'Golden' papaya fruit harvested at different maturity stages
Provedor de dados: 61
Autores: Bron,Ilana U.; Jacomino,Angelo P.
The objective of this study was to determine how ripening physiology and quality of 'Golden' papaya are affected by maturity stages at harvest. Papayas were harvested at four maturity stages (Stage 0: totally green; Stage 1: up to 15% of yellow skin; Stage 2: 16-25% of yellow skin; Stage 3: 26-50% of yellow skin) and evaluated during ripening at 23ºC. Physical and physico-chemical (skin color, pulp firmness, soluble solids, titratable acidity, and ascorbic acid), physiological (respiratory activity and ethylene production), and sensorial (flavor, odor, firmness, and appearance) characteristics were evaluated. Regardless of maturity stages, fruit showed similar variation in respiration rate, exhibiting constant values after the 2nd day of storage at 23ºC...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Carica papaya; Ethylene; Harvest time; Postharvest; Respiration.
Ano: 2006
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202006000300005

Growth and total-N content of Prosopis juliflora (SW) D. C. are stimulated by low NaCl levels
Provedor de dados: 61
Autores: Viégas,Ricardo Almeida; Fausto,Maria José Martins; Queiroz,José Elenildo; Rocha,Iza Marineves Almeida; Silveira,Joaquim Albenísio Gomes; Viégas,Pedro Roberto Almeida.
In this study the early effects of salinity on growth, total N and ion accumulation and partitioning in Prosopis juliflora (common name algaroba) were studied with 30-day-old plants grown for 8 days in aerated nutrient solution (NS) free of (control) or supplied with 25, 50, 75 and 100 mmol.L-1 NaCl. Plants grown in 25 and 50 mmol.L-1 NaCl accumulated a total dry mass (DM) and shoot N content greater than the control. However, at 75 and 100 mmol.L-1 NaCl such parameters were diminished. Whole plant transpiration rates were higher with 25 and 50 mmol.L-1 NaCl and lower with 75 and 100 mmol.L-1 NaCl. Salinity did not influence shoot (80%) and root (70%) water content (WC) but reduced the K+ content of shoot while that of root was not affected. Increasing...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Ion partitioning; Nitrogen; Salinity stress.
Ano: 2004
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202004000100009

Photosynthetic characteristics of a tropical population of Nitella cernua (Characeae, Chlorophyta)
Provedor de dados: 61
Autores: Vieira Jr.,Jair; Necchi Jr.,Orlando.
Photosynthetic characteristics (assessed by chlorophyll fluorescence and O2 evolution) were analysed monthly during one year in a tropical population of Nitella cernua from southeastern Brazil (20º50'32" S, 49º26'15" W). Parameters derived from photosynthesis-irradiance (PI) curves by fluorescence (high values of the photosynthetic parameter, Ik, and lack or low values of photoinhibition, beta) suggested adaptation to high irradiance, whereas those by O2 evolution showed a different pattern (low values of Ik and compensation irradiance, Ic, high values of photosynthetic efficiency, alpha, and photoinhibition). Parameters from PI curves by O2 evolution suggested light acclimation: Ik and maximum photosynthetic rate, Pmax (as rETR, relative electron transfer...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Charophytes; Irradiance; Nitella; PH; Photosynthesis; Seasonal dynamics; Temperature.
Ano: 2006
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202006000300004

Exploring drought tolerance in coffee: a physiological approach with some insights for plant breeding
Provedor de dados: 61
Autores: DaMatta,Fábio Murilo.
This paper briefly reviews some selected traits (leaf area, crown architecture, water-use efficiency and carbon isotope discrimination, water relations and root characteristics), which may be explored in breeding programmes to tolerance to drought stress in arabica and robusta coffee.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Coffea; Water deficit; Water use; Yield.
Ano: 2004
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202004000100001

The role of γ -aminobutyric acid (Gaba) in somatic embryogenesis of Acca sellowiana Berg. (Myrtaceae)
Provedor de dados: 61
Autores: Booz,Maristela Raitz; Kerbauy,Gilberto B.; Guerra,Miguel Pedro; Pescador,Rosete.
The γ-aminobutyric acid (Gaba) is a non-protein amino acid found in prokaryotes and eukaryotes. Its role in plant development has not been fully established. This study reports a quantification of the levels of endogenous Gaba, as well as investigation of its role in different stages of somatic embryogenesis in Acca sellowiana Berg. (Myrtaceae). Zygotic embryos were used as explants and they were inoculated into the culture medium contained different concentrations of Gaba (0,2, 4, 6, 8 and 10 µM). The highest concentrations of endogenous Gaba were detected between the third and nine days after inoculation, reaching the value of 12.77 µmol.g-1FW. High frequency of somatic embryogenesis was observed in response to 10 µM Gaba. This treatment also resulted in...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Amino acid; Pineapple guava; Plant growth.
Ano: 2009
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202009000400003

Changes in pectins of the Xylopodium of Ocimum nudicaule from dormancy to sprouting
Provedor de dados: 61
Autores: Braga,Márcia Regina; Carpita,Nicholas C.; Dietrich,Sonia M. C.; Figueiredo-Ribeiro,Rita de Cássia L.
The thickened underground organ of Ocimum nudicaule is a tuber-like structure (xylopodium) that is dormant in winter and sprouts at the beginning of the spring. Changes in content of cell wall polysaccharides were shown to occur from dormancy to sprouting. Pectic polysaccharides of O. nudicaule were analyzed in relation to composition, molecular mass, and linkage structure in these two phenological phases. The pectin content was 33 % lower during sprouting when compared to dormancy. Changes were also observed in the molecular mass of the pectin fraction from dormancy to sprouting. Galacturonic acid was the predominant sugar, suggesting the presence of a homogalacturonan as the main pectic polysaccharide. A decrease in the acidic polysaccharides,...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Cell-wall polysaccharides; Cerrado; Lamiaceae; Underground reserve organs; Xylopodium.
Ano: 2006
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202006000200009

Differential capacity of nitrogen assimilation between apical and basal leaf portions of a tank epiphytic bromeliad
Provedor de dados: 61
Autores: Takahashi,Cassia A.; Ceccantini,Gregório C.T.; Mercier,Helenice.
The leaf is the main organ of the vegetative body of tank epiphytic bromeliads, which may be subdivided into apical and basal parts. Little is known about the existence of morphological, anatomical or physiological differences between these two leaf portions. The objective of this study was to verify the existence of a differential capacity to assimilate nitrogen from urea between basal and apical leaf portions of Vriesea gigantea, a tank epiphytic bromeliad. Plants were cultivated in vitro in the presence of 5 mM urea for 15 days. During this period, the activities of the enzymes glutamine synthetase (GS, EC 6.3.1.2) and NADH-dependent glutamate dehydrogenase (NADH-GDH, EC 1.4.1.2) were quantified, as well as the densities of trichomes and stomata found...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Bromeliaceae; Glutamate dehydrogenase; Glutamine synthetase; Stomata; Trichome; Urea.
Ano: 2007
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202007000200004

The role of matrix effects on the quantification of abscisic acid and its metabolites in the leaves of Bauhinia variegata L. using liquid chromatography combined with tandem mass spectrometry
Provedor de dados: 61
Autores: Silva,Carolina M. Santiago da; Habermann,Gustavo; Marchi,Mary R. R.; Zocolo,Guilherme J.
Phytohormone analysis using liquid chromatography combined with tandem mass spectrometry is a very important tool for studies involving plant metabolism; however, this analysis can be affected by matrix composition. Although it is necessary to understand this effect to produce reliable results, it has been widely neglected in analyses of plant hormones. Leaf extracts from Bauhinia variegata were obtained by solvent extraction followed by solid-phase cleanup. The extract was analyzed with liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS) in negative ionization mode, using the multiple reaction monitoring mode with two or three transitions to enhance analytical quality control. Although deuterated standards were used as...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: ABA-β-D-glucosyl ester; ABA daily variations; Dihydrophaseic acid; LC-ESI-MS/MS; Phaseic acid.
Ano: 2012
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202012000300009

Effects of early and late season defoliation on photosynthesis, growth and yield of mustard (Brassica juncea L.)
Provedor de dados: 61
Autores: Khan,N.A.; Lone,P.M.
Mustard (Brassica juncea L.) is characterized by a large number of leaves in the lower layers. These leaves are poorly illuminated, remain below the light compensation point and abscise at maturity. The effects of removing 50 % of all leaves taken from the lower half of the plant at 40 (pre-flowering) or 60 (post-flowering) days after sowing (DAS) were studied on photosynthesis and growth at 80 DAS and on yield at harvest. A comparison of stomatal and mesophyll effects on photosynthesis upon removal of such leaves was also made. Defoliation at 40 DAS resulted in a higher rate of photosynthesis (P N), growth and yield compared to defoliation at 60 DAS or the no defoliation control. The non-significant variation in stomatal limitation (I S), increased...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Carbonic anhydrase; Dry mass; Stomatal limitation.
Ano: 2005
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202005000100015

Effect of temperature on polyunsaturated fatty acid accumulation in soybean seeds
Provedor de dados: 61
Autores: Lanna,Anna Cristina; José,Inês Chamel; Oliveira,Maria Goreti de Almeida; Barros,Everaldo Gonçalves; Moreira,Maurilio Alves.
Soybean oil contains around 60 % of polyunsaturated fatty acids, which are responsible for the low oxidative stability of soy-derived products. Soybean lines with low linolenic acid content can be obtained by genetic manipulation; however, a high proportion of the variation in fatty acids content is due to environmental factors. This work aimed to determine the effect of temperature on oil composition and on the activity of the enzymes CDP-choline:1,2-diacylglycerolcholine phosphotransferase (CPT) and acyl-CoA:lysophosphatidylcholine acyltransferase (LPCAT), responsible for maintenance of polyunsaturated fatty acids in the cytoplasmic acyl-CoA pool, that is used for oil synthesis in the seeds. CAC-1, a soybean variety with linolenic acid content of about 8...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Cholinephosphotransferase; Kinetic characterization; Linoleic acid; Linolenic acid; Lysophosphatidylcholine acyltransferase; Soybean seed.
Ano: 2005
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202005000200004

Effects of changes in the photosynthetic photon flux density on net gas exchange of Citrus limon and Nicotiana tabacum
Provedor de dados: 61
Autores: Pimentel,Carlos; Ribeiro,Rafael Vasconcelos; Santos,Mauro Guida dos; Oliveira,Ricardo Ferraz de; Machado,Eduardo Caruso.
The objective of this study was to evaluate the effects of changes in the photosynthetic photon flux density (PPFD) on net gas exchange of Citrus limon, a woody species, and Nicotiana tabacum, an herbaceous species. When PPFD was increased from 50 to 350 mumol.m-2.s-1 and returned to 50 mumol.m-2.s-1 after 60 min, the CO2 assimilation rate (A) increased and stabilized after 15 min in both species. Stomatal conductance (g s), however, continued to increase. After returning to low PPFD, A immediately diminished to a low value for both lemon and tobacco. Stomatal conductance of lemon diminished slowly over 60 min, whereas g s for tobacco took only 15 min to decrease. This difference in behavior is probably due to over-sensitivity of stomata of woody species,...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: CO2 assimilation rate; Gas exchange; Stomata; Intrinsic water use efficiency.
Ano: 2004
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202004000200002

Response to chitin in suspension-cultured Citrus aurantium cells
Provedor de dados: 61
Autores: Gallão,Maria I.; Cortelazzo,Angelo L.; Fevereiro,Manoel P. S.; Brito,Edy S. de.
Morphological changes and enzyme activity in suspension-cultured cells of Citrus aurantium were followed after chitin elicitation. Chitin oligomers presented a rapid effect with a maximum activity after 3 h followed by a gradual decrease to the original levels at 8 h of incubation. Cell walls presented a lignification process and the cytoplasmatic protein became less reactive to anionic stains. In the treated material a reduction in starch grain size, an increase in the number of autophagic vacuoles, deposition of secretion in the pericellular space and a defibrillation of the cell-wall polymers were observed. Chitin oligomers increased peroxidase and L-phenylalanine ammonia-lyase activities. Extracellular peroxidase activity increased from 0.20 U mL-1...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Chitin; Citrus aurantium; Elicitation; L-phenylalanine ammonia-lyase; Peroxidase.
Ano: 2007
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202007000100008

L-myo-InositoL-1- phosphate synthase from bryophytes: purification and characterization of the enzyme from Lunularia cruciata (L.) Dum
Provedor de dados: 61
Autores: Chhetri,Dhani Raj; Yonzone,Sachina; Tamang,Sanjeeta; Mukherjee,Asok Kumar.
L-myo-inositol-1-phosphate synthase (MIPS; EC: 5.5.1.4) catalyzes the conversion of D-glucose-6-phosphate to 1L-myo-inositol-1-phosphate, the rate limiting step in the biosynthesis of all inositol containing compounds. Myo-inositol and its derivatives are implicated in membrane biogenesis, cell signaling, salinity stress tolerance and a number of other metabolic reactions in different organisms. This enzyme has been reported from a number of bacteria, fungi, plants and animals. In the present study some bryophytes available in the Eastern Himalaya have been screened for free myo-inositol content. It is seen that Bryum corinatum, a bryopsid shows the highest content of free myo-inositol among the species screened. Subsequently , the enzyme MIPS has been...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: D-glucose-6-phosphate; Inositol monophosphatase; Inositol synthase; Myo-inositol; L-myo-inositoL-1-phosphate.
Ano: 2009
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202009000300008

Seed germination in Cerrado species
Provedor de dados: 61
Autores: Zaidan,Lilian B. P.; Carreira,Rosana C.
The aim of this review is to comment on the available data about germination of seeds from herb, shrub and tree species of the Cerrado after the publication of the review written by Felippe and Silva in 1984. Studies on seed germination of herbaceous species focused mainly on the responses of seeds to light, different ranges of temperature and storage in the soil. The majority of seeds from herb species germinate between 20°C and 30°C, and are photoblastic. Alternate temperatures favored germination in some seeds, but changed light sensitivity of the achenes of Bidens gardneri. Seeds of most of the shrub species of Melastomataceae are positive photoblastic; among the Velloziaceae, germination in the dark was observed in some species. Other shrub species...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Dormancy; Photoblastism; Soil seed bank; Temperature.
Ano: 2008
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202008000300002

Oxidative stress in five wheat varieties (Triticum aestivum L.) exposed to water stress and study of their antioxidant enzyme defense system, water stress responsive metabolites and H2O2 accumulation
Provedor de dados: 61
Autores: Chakraborty,Usha; Pradhan,Bhumika.
Five varieties of wheat (Triticum aestivum L.) - KW, UP 2752, PBW 343, SO and LV - were subjected to water stress and sampling was done on the 3rd, 6th and 9th day of stress. RWC decline in KW, UP 2752 and PBW 343 (36.65, 42.34 and 40.75% respectively) was comparatively lesser than in LV and SO (52.93 and 52.67% respectively). In all varieties tested, three antioxidant enzymes (POX, APOX and GR) showed an initial increase. The activity of POX and GR increased with the increase in the duration of stress in KW, UP 2752 and PBW 343, while the activity of APOX declined. However, CAT and SOD showed an initial increase in these varieties, whereas it declined in SO and LV with increase in the period of stress. Accumulation of H2O2 declined during prolonged water...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Antioxidants; Carotenoids; Drought; Lipid peroxidation.
Ano: 2012
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202012000200005

Optimizing exponential growth of Triticum aestivum by application of the relative addition rate (RAR) technique utilizing a computer-controlled nutrient delivery system
Provedor de dados: 61
Autores: Pintro,José Carlos; Taylor,Gregory James; Matumoto-Pintro,Paula Toshimi.
We conducted experiments designed to assess whether plants can be grown under conditions of low ionic strength simulating natural soil conditions. Wheat (Triticum aestivum, cv. Atlas 66) plants were grown using ten different relative nutrient addition rates (RAR) of nutrients (0.00, 0.06, 0.09, 0.12, 0.15, 0.18, 0.21, 0.24, 0.27, and 0.30 day-1) with a background solution containing 50 µmol.L-1 N and all other essential nutrients in optimal proportions relative to N. The relative growth rate (RGR) of plants over a 19-day experimental period responded directly to RAR (from 0.06 to 0.21 day-1) with a linear slope of 0.56 and an intercept of 0.085 day-1. Solution electrical conductivity (EC) values remained relatively stable over the experimental period. We...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Growth; Ionic strength; Nutrient solution; Wheat.
Ano: 2004
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202004000300006

Ethylene and abscisic acid in the control of development of the rhizome of Kohleria eriantha (Benth.) Hanst. (Gesneriaceae)
Provedor de dados: 61
Autores: Almeida,Julieta Andrea Silva de; Kascheres,Concetta; Pereira,Maria de Fátima D.A.
Kohleria eriantha has rhizomes which are underground stems with buds enclosed by modified leaves, that store starch. The buds of this rhizome can develop in two morphological patterns: an aerial shoot (similar to the mother plant) or a rhizome, depending on the water level present in the substrate. Development of the shoot was inhibited by low water availability (1 mL) in the substrate. It was verified that ethylene and ABA were involved in controlling the development of the rhizome pattern under low water availability. Treatments with ethrel, PEG and ABA induced shoot development whereas treatments with AgNO3 or AVG inhibited shoot development. Increased ethylene and ABA were observed under conditions that inhibited shoot development. Moreover, it is...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Abscisic acid; Buds; Ethylene; Meristem; Rhizome.
Ano: 2005
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202005000400007

High temperature effects on the response of photosynthesis to light in sweet orange plants infected with Xylella fastidiosa
Provedor de dados: 61
Autores: Ribeiro,Rafael Vasconcelos; Machado,Eduardo Caruso; Oliveira,Ricardo Ferraz de; Pimentel,Carlos.
The objective of this study was to evaluate the high temperature effects on the response of photosynthesis to light in sweet orange plants infected with Xylella fastidiosa. This vascular bacterium is the causal agent of the citrus variegated chlorosis that causes severe economical losses to the Brazilian citrus industry. The responses of the photosynthetic oxygen evolution and the parameters related to chlorophyll a fluorescence to the increase in light intensity were evaluated at 35ºC and 45ºC in both healthy and infected leaf discs. The increase in temperature affected the photosynthetic apparatus of both healthy and infected plants, although infected plants showed higher photochemical sensitivity at the higher temperature (e.g. in the potential quantum...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Chlorophyll fluorescence; Citrus sinensis; Light response curve; Photosynthesis; Temperature; Xylella fastidiosa.
Ano: 2003
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202003000200004

Phytochelatins
Provedor de dados: 61
Autores: Inouhe,Masahiro.
Phytochelatins (PCs) were first discovered as Cd-binding "Cadystins A and B" in a fission yeast and then in many plants as the major components of Cd-binding complexes. PCs have the general structure of (gamma-glutamyl-cysteinyl)n-glycine (n=2-11) and the variants with the repeated gamma-glutamyl-cysteinyl units are formed in some plants and yeast. They are capable of binding to various metals including Cd, Cu, Zn or As via the sulfhydryl and carboxyl residues, but their biosyntheses are controlled preferentially by the metal Cd or metalloid As. PCs are synthesized from glutathione (gamma-glutamyl-cysteinyl-glycine) in steps mediated by PC synthase. Genes (CAD1, PCS1) of the enzyme have been isolated from plants, fission yeast and some animals. Inhibition...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Arsenic; Cadmium-binding peptides; Heavy metal-tolerance; Phytochelatin; Phytoremediation.
Ano: 2005
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202005000100006

Glomus intraradices improved salt tolerance in Prosopis alba seedlings by improving water use efficiency and shoot water content
Provedor de dados: 61
Autores: Scambato,Agustina A.; Echeverria,Mariela; Sansberro,Pedro; Ruiz,Oscar A.; Menéndez,Ana Bernardina.
The present work was aimed at testing the hypothesis that mycorrhizal Prosopis alba, an economically important tree species worldwide, presents increased salt-tolerance compared with non-mycorrhizal ones and at gaining insight into the possible mechanisms underlying that improvement. For this purpose, a randomized complete block experiment with two factors: mycorrhizal treatments with or without the arbuscular fungus Glomus intraradices and two salinity levels, 0 and 200 mM NaCl was performed. Plant growth in P. alba plants colonized by G. intraradices was less affected by salinity than that in non-arbuscular mycorrhizal (AM) plants, indicating that mycorrhizal colonization turned P. alba more tolerant to salinity. Photosynthesis was reduced by salinity in...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Photosynthesis; Salinity; Stomatal conductance; Transpiration ratio; Proline.
Ano: 2010
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202010000400008

Water deficit effect on the accumulation of biomass and artemisinin in annual wormwood(Artemisia annua L., Asteraceae)
Provedor de dados: 61
Autores: Marchese,José A.; Ferreira,Jorge F.S.; Rehder,Vera L.G.; Rodrigues,Osmar.
Despite the importance of Artemisia annua L. as the only source of the anti-parasitic drug artemisinin, little is known on the effects of biotic and abiotic stress on artemisinin accumulation. Water deficit is the most limiting factor on plant growth, however it can trigger secondary metabolite accumulation, depending on the plant growth stage and intensity. A. annua cultivated in growth chambers was submitted to five water deficit treatments (watered, 14, 38, 62 e 86 hours without irrigation). Water deficits of 38 and 62 hours (Yw = -1.39 and -2.51 MPa, respectively) increased leaf artemisinin content, but only 38 hours led to a significant increase in both leaf and plant artemisinin (29%), with no detriment to plant biomass production. The other...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Malaria; Secondary metabolism; Terpene; Drought; Water stress.
Ano: 2010
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202010000100001

Osmotic adjustment in roots and leaves of two sorghum genotypes under NaCl stress
Provedor de dados: 61
Autores: Lacerda,Claudivan Feitosa de; Cambraia,José; Oliva,Marco Antonio; Ruiz,Hugo Alberto.
Seedlings of two sorghum genotypes [Sorghum bicolor (L.) Moench], one salt tolerant (CSF 20) and the other salt sensitive (CSF 18) were grown in nutrient solution containing 0, 50 and 100 mmol.L-1 NaCl for seven days and the osmotic potential (Ys) and the contribution of organic and inorganic solutes to the Ys were determined in the leaves and roots. Salinity reduced the Ys of the cellular sap of leaves and roots in both genotypes, mainly in the salt sensitive one. The higher decrease in the Ys in the salt sensitive genotype was mostly due to higher accumulation of Na+ and Cl- that probably exceeded the amount needed for the osmotic adjustment. Among the inorganic solutes, K+ contributed the most to the Ys in control unstressed seedlings, but its...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Ions; Organic solutes; Osmotic adjustment; Salinity; Sorghum bicolor.
Ano: 2003
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202003000200007

Molecular characterization of the polyphenol oxidase gene in lulo (Solanum quitoense Lam.) var. Castilla
Provedor de dados: 61
Autores: Arias,Duverney Gaviria; Doria,Clara María Mejía; Ramos,Lucero Rengifo; Morocho,Heydy Catalina Navia.
Lulo (Solanum quitoense Lam.) is an exotic fruit from the Andes Mountains with a high export potential. However, the browning that is produced during harvest and the postharvest processes alters the organoleptic and nutritional properties of this fruit, which has made its management as a fresh fruit difficult. The browning processes are regulated by the enzyme family of the polyphenol oxidases (PPOs) located in the thylakoids of the chloroplast. When there is damage at the tissue level, the phenolic compounds found in the vacuoles enter into contact with the polyphenol oxidase. This enzyme produces polymerization among the phenolic compounds, as well as between them and the proteins and cell walls. This study analyzed the polyphenol oxidase in lulo var....
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Enzymatic browning; DNA sequencing; Solanaceae; UTRA domain.
Ano: 2012
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202012000400005

Activation of nitrate reductase of cashew leaf by exogenous nitrite
Provedor de dados: 61
Autores: Viégas,Ricardo Almeida; Silveira,Joaquim Albenísio Gomes.
Nitrate reductase (NR) plays a central role in plant primary metabolism and exhibits complex regulation mechanisms for its catalytic activity. There is controversy in the literature concerning the possible direct effect of NO2- on the stimulation and/or activation of NR activity. The influence of NO2- was studied on the NR activity in the leaves of 30-day-old cashew (Anacardium occidentale L.) seedlings. Addition of NO2- to the reaction mixture containing leaf enzymatic extract resulted in a remarkable increase in NR activity. A trace amount (5 mumol.L-1) of NO2- was required to achieve full NR activity. The in vitro NR-activity showed a steady time-dependent increase when incubated in the presence of only NO3- + NO2-. In contrast, in vitro NR activity was...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Anacardium occidentale; Enzymes; NADH; Nitrate metabolism; Nitrate reductase.
Ano: 2002
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202002000100005

Leaf anatomy and carbon isotope composition in Coffea species related to photosynthetic pathway
Provedor de dados: 61
Autores: Carelli,Maria Luiza Carvalho; Queiroz-Voltan,Rachel Benetti; Fahl,Joel Irineu; Trivelin,Paulo César Ocheuze.
Possible presence of vascular bundle sheath cells and its relation to photosynthetic pathway, leaf anatomy and carbon isotope composition (delta13C) were examined in six species of genus Coffea: C. arabica (cvs. Catuaí Vermelho, Mundo Novo, Bourbon Vermelho and Icatu Amarelo), C. canephora (cvs. Apoatã and Guarini), C. liberica, C. dewevrei, C. salvatrix and C. stenophylla. In all genotypes, the vascular bundle was surrounded by a layer of cells with numerous chloroplasts in a centrifugal position. Visually no differences could be seen between the spongy parenchyma cells and the bundle sheath cells, neither in size nor in chloroplast number. The leaf delta13C values ranged between a maximum of - 26.2 ‰ in C. salvatrix and a minimum of -29.7 ‰ in C....
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Bundle sheath cells; Coffea; Leaf anatomy; Leaf carbon isotope composition.
Ano: 2003
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202003000100003

Effects of hydric deficiency on gas exchange parameters and metabolism of Eucalyptus grandis clones
Provedor de dados: 61
Autores: Coscolin,Renata B. S.; Broetto,Fernando; Marchese,José A.; Campohermoso,Marco C.; Paladini,Marcos V.
The metabolic effects caused by hydric deficiency (HD) on Eucalyptus grandis clones were assessed by an experiment where plants were cultivated in four blocks. The first was the control block, normally irrigated, whereas the other three blocks were submitted to cycles of hydric deficiency. Analysis of photosynthetic efficiency, enzymatic activity of antioxidant response system, level of pigments and L-proline concentration were performed to evaluate the HD effects. Results showed that HD altered some parameters related to photosynthetic activity, pigments accumulation, proline and enzymatic activity. Clone 433 of E. grandis presented higher response ability to HD.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Enzymes; Eucalypt; Hydric deficiency; Photosynthesis.
Ano: 2011
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202011000400002

The effect of chilling on the photosynthetic activity in coffee (Coffea arabica L.) seedlings: The protective action of chloroplastid pigments
Provedor de dados: 61
Autores: Oliveira,Jurandi Gonçalves de; Alves,Pedro Luis C.A.; Magalhães,Antonio Celso.
Coffea arabica is considered to be sensitive to low temperatures, being affected throughout its entire life cycle. Injury caused by chilling (low temperatures above zero degree centigrade) is characterized primarily by inhibition of the photosynthetic process. The objective of this work was to evaluate the role of photosynthetic pigments in the tolerance of coffee (C. arabica L.) seedlings to chilling. The evaluation the photosynthetic activity was made by emission of Chl a fluorescence at room temperature (25 ºC) in vivo and in situ, using a portable fluorometer. The pigment content was obtained by extraction with 80 % acetone, while estimation of membrane lipid peroxidation was determined by measuring the MDA content in leaf tissue extracts. The results...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Chlorophyll a fluorescence; Coffee; Lipid peroxidation; Photosynthetic pigments.
Ano: 2002
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202002000200003

Purification and partial characterization of a lectin from Caesalpinia tinctoria Domb, ex Dc fruits
Provedor de dados: 61
Autores: Oliveira,Marli Lourdes de; Beltramini,Leila Maria; Simone,Salvatore Giovanni de; Brumano,Maria Helena Nasser; Silva-Lucca,Rosemeire Aparecida; Nakaema,Marcelo Kiyoshi Kian; Pires,Christiano Vieira; Oliveira,Maria Goreti de Almeida.
A lectin was isolated from the pod saline extract of Caesalpinia tinctoria by dialoconcentration on Centripep-10 and affinity chromatography on chitin column. The purified lectin was partially characterized with respect to its biochemical and structural properties. It contains 8.3 % of carbohydrate and exhibited an agglutinating activity against human erythrocytes (ABO groups). Its amino acid composition was characterized by a great number of acidic and hydrophobic residues and the estimated molecular mass was 12.5 kDa. The presence of only one N-terminal amino acid sequence (D¹-V-P-A-Y-V-Y-V-H-F10-G-F-G-E-E-H-R -D-V-F20-D), showed the homogeneity of the purified lectin. The far-ultraviolet circular dichroism (CD) spectrum of lectin indicated that it...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Circular dichroism; Leguminosae; Plant defense; Pod; Secondary structure.
Ano: 2003
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202003000200008

Expression of heat shock protein and trehalose-6-phosphate synthase homologues induced during water deficit in cotton
Provedor de dados: 61
Autores: Nepomuceno,Alexandre Lima; Oosterhuis,Derrick; Stewart,James McD; Turley,Rickie; Neumaier,Norman; Farias,José Renato Bouças.
Tolerance to drought in plants is not a simple trait, but a complex of mechanisms working in combination to avoid or to resist water deficit. Genotypes that differ in tolerance to water deficit may show qualitative and quantitative differences in gene expression when submitted to drought periods. Four cotton (Gossypium hirsutum L.) genotypes (Siokra L-23, Stoneville 506, CS 50 and T-1521) with contrasting responses to water deficit stress were studied using the Differential Display (DD) technique to identify and isolate genes which may differ among them. Fifty-two cDNA fragments differentially expressed during water deficit were isolated, cloned and sequenced. Search of gene bank databases showed that two cDNA clones, A12B15-6 and A12B13-1, have high...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Calmodulin; Drought; Gene expression; Gossypium hirsutum L.; Trehalase.
Ano: 2002
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202002000100002

Ripening of "Pedro Sato" guava: study on its climacteric or non-climacteric nature
Provedor de dados: 61
Autores: Azzolini,Marisa; Jacomino,Angelo Pedro; Bron,Ilana Urbano; Kluge,Ricardo Alfredo; Schiavinato,Marlene Aparecida.
Guava (Psidium guajava L.) is a tropical fruit exhibiting rapid post-harvest ripening. However, the physiological basis involved in the ripening process of guava is not totally clear, which makes it difficult to develop technologies to enhance fruit storability. Two experiments were carried out with the objective of determining the ripening behavior of 'Pedro Sato' guavas. In the first experiment, guava fruits at three maturity stages (I - dark green, II - light green and III - yellow-green) were stored at room temperature (23 ± 1°C and 85 ± 5 % RH). The respiratory rate, ethylene production, pulp and skin colours, and firmness were evaluated. In the second experiment, ethylene and 1-methylcyclopropene (1-MCP) were applied to guavas at the light green...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Psidium guajava; Ethylene; 1-methylcyclopropene; Respiration.
Ano: 2005
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202005000300004

Morphological analysis and photosynthetic performance of improved papaya genotypes
Provedor de dados: 61
Autores: Torres Netto,Alena; Campostrini,Eliemar; Azevedo,Letícia C.; Souza,Marcelo A.; Ramalho,José C.; Chaves,Manuela M.
Brazil is the largest world producer of papaya and the third largest exporter despite of only 1.5 to 2.0% of its production is exported. Such an underexplored exportation potential highlight the necessity for physiological studies on new cultivars and hybrids to verify their agronomic and commercial viability. Two Brazilian states, Bahia and Espirito Santo, are responsible for 80% of national production. Papaya can also be an agricultural alternative to north / northeast of Rio de Janeiro, because the region is close to consumer centers and have similar environmental conditions of the most productive regions. Nevertheless, it is worth to develop cultivars that can express the highest yield potential in this region. The aim of this work was to characterize...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Carica papaya L.; Fluorescence; Gas exchange; Genotypes; Growth analyses.
Ano: 2009
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202009000300005

Heat treatment effects on ACC oxidase activity of 'Keitt' mangoes
Provedor de dados: 61
Autores: Bender,Renar João; Seibert,Eduardo; Brecht,Jeffrey K.
With the use of ethylene dibromide for mango disinfestation being ruled out, vapor heat or hot water treatments are the only alternatives for quarantine treatments of mangoes. Physical treatments such as heat treatments have been implicated in higher incidence of physiological disorders and enhancement of ripening processes. Therefore, the objective of the present work was to determine the effects of hot water treatments on ethylene production and on the in vitro activity of ACC oxidase. Cv. Keitt mangoes were immersed for 3 min in hot water at 53 °C or 90 min in water at 46 °C. Immediately after the treatments, some of the mangoes were analyzed for ACC oxidase activity and others were stored to be analyzed after 4 days at 12 °C. There was a significant...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Ethylene; Ethylene dibromide; Heat treatment; Mangifera indica L.
Ano: 2003
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202003000300003

Improving reproductive efficiency of chickpea by foliar application of zinc
Provedor de dados: 61
Autores: Pathak,Girish Chandra; Gupta,Bhavana; Pandey,Nalini.
Zinc deficiency is not only the cause of low productivity of crops, but it also results in low zinc content in seeds, which leads to poor dietary zinc intake. To study the effect of zinc foliar application on improving plant yield and seed zinc content for human consumption, chickpea plants were raised in refined sand culture with deficient (0.2 µM) and sufficient (1µM) supply of zinc under glass-house conditions. Prior to initiation of the reproductive phase, zinc was applied as 0.1% ZnSO4 foliar spray to both zinc sufficient and deficient plants. The plants exposed to different zinc treatments were studied for pollen and stigma structure and their involvement in fertilization and seed yield. Zinc deficiency induces flower abortion, pollen, and ovule...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Cicer arietinum (L.); Foliar application; Reproductive development; Zinc deficiency.
Ano: 2012
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202012000300004

Mutagenesis in Petunia x hybrida Vilm. and isolation of a novel morphological mutant
Provedor de dados: 61
Autores: Berenschot,Amanda S.; Zucchi,Maria I.; Tulmann-Neto,Augusto; Quecini,Vera.
Traditionally, mutagenesis has been used to introduce novel genetic variability in ornamental crops. More recently, it has become a powerful tool in gene discovery and functional analyses in reverse genetics approaches. The present work aimed to compare the efficiency of physical and chemical agents in generating mutant populations of petunia. We have indirectly evaluated the genomic damage by analyzing developmental characteristics of the plantlets derived from treated seeds employing gamma radiation at 0, 20, 40, 60, 80 and 100 Gy and the alkylating agent ethyl-methanesulfonate (EMS) at 0, 0.05, 0.1, 0.15, 0.2 and 0.25% (v/v). Gamma rays and EMS caused developmental defects and decreased seedling viability in plants obtained from the mutagenized seeds....
Tipo: Info:eu-repo/semantics/article
Palavras-chave: EMS; Gamma irradiation; Genomic damage; Mutagenesis; Reverse genetics.
Ano: 2008
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202008000200002

Identifying Eucalyptus expressed sequence tags related to Arabidopsis flowering-time pathway genes
Provedor de dados: 61
Autores: Dornelas,Marcelo Carnier; Rodriguez,Adriana Pinheiro Martinelli.
Flowering initiation depends on the balanced expression of a complex network of genes that is regulated by both endogenous and environmental factors. The timing of the initiation of flowering is crucial for the reproductive success of plants; therefore, they have developed conserved molecular mechanisms to integrate both environmental and endogenous cues to regulate flowering time precisely. Extensive advances in plant biology are possible now that the complete genome sequences of flowering plants is available and plant genomes can be comprehensively compared. Thus, association studies are emerging as powerful tools for the functional identification of genes involved on the regulation of flowering pathways. In this paper we report the results of our search...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: CONSTANS; Data mining; EST; Photoperiod; Vernalization.
Ano: 2005
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202005000200009

Antioxidant-enzymatic system of two sorghum genotypes differing in salt tolerance
Provedor de dados: 61
Autores: Costa,Paulo Henrique Alves da; Neto,André Dias de Azevedo; Bezerra,Marlos Alves; Prisco,José Tarquinio; Gomes-Filho,Enéas.
Two forage sorghum genotypes were studied: CSF18 (salt-sensitive) and CSF20 (salt-tolerant). Shoot growth reduction as a result of salt stress was stronger in the salt sensitive genotype compared to the salt tolerant one. When the two genotypes were subjected to salt stress (75 mM NaCl) no significant change in lipid peroxidation was observed. However, salt stress induced increases in superoxide dismutase and catalase activities in both genotypes. These salt-induced increases were higher in the salt-tolerant genotype. Peroxidase activity was differentially affected by salt stress in the two genotypes. The activities of these peroxidases were decreased by salt stress in the salt-sensitive genotype and increased in the salt-tolerant genotype. In addition,...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Sorghum bicolor; Antioxidant-enzymatic system; Lipid peroxidation; Oxidative stress; Salinity.
Ano: 2005
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202005000400003

Changes in phosphate content and phosphatase activities in rice seedlings exposed to arsenite
Provedor de dados: 61
Autores: Mishra,Shruti; Dubey,R.S.
The effect of arsenite (As2O3) in situ on the level of the phosphate pool and activities of phosphohydrolytic enzymes was examined in rice (Oryza sativa L.) seedlings grown for 5-20 d in sand cultures. The effects were manifested via a decline in phosphate content and inhibition of the activities of key phosphatases. Application of 50 µM As2O3 in situ resulted in 34 to 77% inhibition of acid phosphatase activity in roots and about 38 to 50% inhibition of activity in shoots of 15-20-d-old seedlings. Similarly, alkaline phosphatase activity was inhibited in shoots under in situ As (III) toxicity. Varietal as well as organ specific differences were observed in the response of inorganic pyrophosphatase activity to in situ As (III) treatment. A moderately toxic...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Arsenite; Chloroplast; Mitochondria; Oryza sativa; Phosphate; Phosphatases.
Ano: 2008
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202008000100003

Growth evaluation and water relations of Erythrina velutina seedlings in response to drought stress
Provedor de dados: 61
Autores: Silva,Elizamar Ciríaco da; Silva,Marcos F. A.; Nogueira,Rejane J. M. C.; Albuquerque,Manoel B.
Erythrina velutina Willd. (common name: mulungu) is a deciduous, heliophyte found in the semi-arid region of northeastern Brazil. To evaluate the growth and water relations of mulungu seedlings in soils with different degrees of moisture content, an experiment was carried out under greenhouse conditions using four water treatments (100%, 75%, 50% and 25% of the field capacity- FC). Predawn (Ψpdw) and midday leaf water potential (Ψmdw), relative water content (RWC), plant height, number of leaves, stem diameter, leaf area (LA), specific leaf area (SLA), leaf area ratio (LAR), dry matter in different organs, biomass partitioning and root:shoot ratio were evaluated. No differences were detected between treatments for Ψpdw after 30 days; however, at midday,...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Biomass allocation; Dry matter; Leaf area; Root to shoot ratio; Relative water content; Water potential.
Ano: 2010
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202010000400002

Effects of light and ethylene on endogenous hormones and development of Catasetum fimbriatum (Orchidaceae)
Provedor de dados: 61
Autores: Suzuki,Rogério M.; Kerbauy,Gilberto B.
This study attempted to clarify the effects of dark, light and ethylene on plant growth and endogenous levels of indole-3-acetic acid (IAA), cytokinins and abscisic acid in Catasetum fimbriatum. Dark-incubation fully inhibited root and pseudobulb formation as well as leaf growth, but favored shoot elongation. The results of continuous and active growth in dark-incubated shoots (stolons) were induced by strong apical meristem sink activity and by the significantly increased levels of cytokinins in shoots. In fact, shoot length, cytokinin and IAA levels in dark-incubated shoots were about twice as great as for those grown under light conditions. Moreover, the total cytokinin level in shoots of C. fimbriatum under light conditions without ethylene was...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Auxin; Cytokinins; Etiolation; Plant growth; Plant hormones.
Ano: 2006
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202006000300002

Brazilian coffee genome project: an EST-based genomic resource
Provedor de dados: 61
Autores: Vieira,Luiz Gonzaga Esteves; Andrade,Alan Carvalho; Colombo,Carlos Augusto; Moraes,Ana Heloneida de Araújo; Metha,Ângela; Oliveira,Angélica Carvalho de; Labate,Carlos Alberto; Marino,Celso Luis; Monteiro-Vitorello,Claúdia de Barros; Monte,Damares de Castro; Giglioti,Éder; Kimura,Edna Teruko; Romano,Eduardo; Kuramae,Eiko Eurya; Lemos,Eliana Gertrudes Macedo; Almeida,Elionor Rita Pereira de; Jorge,Érika C.; Albuquerque,Érika V. S.; Silva,Felipe Rodrigues da; Vinecky,Felipe; Sawazaki,Haiko Enok; Dorry,Hamza Fahmi A.; Carrer,Helaine; Abreu,Ilka Nacif; Batista,João A. N.; Teixeira,João Batista; Kitajima,João Paulo; Xavier,Karem Guimarães; Lima,Liziane Maria de; Camargo,Luis Eduardo Aranha de; Pereira,Luiz Filipe Protasio; Coutinho,Luiz Lehmann; Lemos,Manoel Victor Franco; Romano,Marcelo Ribeiro; Machado,Marcos Antonio; Costa,Marcos Mota do Carmo; Sá,Maria Fátima Grossi de; Goldman,Maria Helena S.; Ferro,Maria Inês T.; Tinoco,Maria Laine Penha; Oliveira,Mariana C.; Van Sluys,Marie-Anne; Shimizu,Milton Massao; Maluf,Mirian Perez; Eira,Mirian Therezinha Souza da; Guerreiro Filho,Oliveiro; Arruda,Paulo; Mazzafera,Paulo; Mariani,Pilar Drummond Sampaio Correa; Oliveira,Regina L.B.C. de; Harakava,Ricardo; Balbao,Silvia Filippi; Tsai,Siu Mui; Mauro,Sonia Marli Zingaretti di; Santos,Suzana Neiva; Siqueira,Walter José; Costa,Gustavo Gilson Lacerda; Formighieri,Eduardo Fernandes; Carazzolle,Marcelo Falsarella; Pereira,Gonçalo Amarante Guimarães.
Coffee is one of the most valuable agricultural commodities and ranks second on international trade exchanges. The genus Coffea belongs to the Rubiaceae family which includes other important plants. The genus contains about 100 species but commercial production is based only on two species, Coffea arabica and Coffea canephora that represent about 70 % and 30 % of the total coffee market, respectively. The Brazilian Coffee Genome Project was designed with the objective of making modern genomics resources available to the coffee scientific community, working on different aspects of the coffee production chain. We have single-pass sequenced a total of 214,964 randomly picked clones from 37 cDNA libraries of C. arabica, C. canephora and C. racemosa,...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Coffea; CDNA; EST; Transcriptome.
Ano: 2006
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202006000100008

Effect of cadmium on growth, micronutrient concentration, and δ-aminolevulinic acid dehydratase and acid phosphatase activities in plants of Pfaffia glomerata
Provedor de dados: 61
Autores: Skrebsky,Etiane C.; Tabaldi,Luciane A.; Pereira,Luciane B.; Rauber,Renata; Maldaner,Joseila; Cargnelutti,Denise; Gonçalves,Jamile F.; Castro,Gabriel Y.; Shetinger,Maria R.C.; Nicoloso,Fernando T.
Pfaffia glomerata (Spreng.) Pedersen plantlets were grown under different cadmium (Cd) concentrations (0, 20, 40, 60 and 80 μM) in a hydroponic system during 7 d. Plant growth, micronutrient, chlorophyll and carotenoid concentrations, as well as δ-aminolevulinic acid dehydratase (ALA-D; E.C.4.2.1.24) and acid phosphatase (AP; E.C.3.1.3.2) activities were then analysed. Cadmium concentration in both shoots and roots increased with increasing external Cd levels. Metal concentration was on average 12-fold greater in root than in shoot tissues. Root length was unaffected by Cd treatments. In contrast, dry weight of both shoot and roots increased significantly upon addition of 20 and 40 μM Cd. Moreover, shoot and total plant dry weight was only reduced in...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Brazilian ginseng; Carotenoid; Chlorophyll; Heavy metal; Micronutrient; Phytoremediation.
Ano: 2008
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202008000400004

Small heat shock proteins genes are differentially expressed in distinct varieties of common bean
Provedor de dados: 61
Autores: Simões-Araújo,Jean Luiz; Rumjanek,Norma Gouvêa; Margis-Pinheiro,Márcia.
Plants respond to temperature stress by synthesizing a set of heat shock proteins (HSPs), which may be responsible for the acquisition of thermotolerance. In this study, the induction of small HSPs (sHSPs) in eight common bean varieties was evaluated by Northern blot analysis using the W HSP 16.9 cDNA as heterologous probe. Cowpea was used, as a positive control since this plant, as opposed to common bean, is known to grow well under high temperature regimes such as that found in the Brazilian semi-arid region. After the growth period, the plants were submitted to two h of heat shock at 40 ºC. All varieties tested were able to induce sHSP mRNAs that hybridized with W HSP 16.9 probe. However, significant kinetic differences were found when comparing...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Common bean; Heat shock proteins; HSPs; Thermotolerance; Temperature stress.
Ano: 2003
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202003000100005

The metabolic response of plants to oxygen deficiency
Provedor de dados: 61
Autores: Sousa,Carlos Antônio Ferreira de; Sodek,Ladaslav.
Plants, under natural or experimental conditions, can be subject to a range of O2 concentrations from normal (normoxia) through deficient (hypoxia) to total absence (anoxia). Many metabolic processes are affected by O2 deficiency but the most studied events are those related to respiration and metabolism of N. In the absence of a terminal electron acceptor for the electron transport chain, the tricarboxylic acid cycle functions only partially and in both directions. Acidification of the cytosol occurs and pyruvate, the product of glycolysis, is transformed to lactate and ethanol, which represent the main fermentation reactions in plants. Alanine is the third most important product of anaerobic metabolism, resulting from high rates of amino acid...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Anoxia; Hypoxia; N metabolism; Fermentation products.
Ano: 2002
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202002000200002

Environmental physiology of the bananas (Musa spp.)
Provedor de dados: 61
Autores: Turner,David W.; Fortescue,Jeanie A.; Thomas,Dane S.
The bananas are thought to be particularly sensitive to changes in the environment. This review considers some historical and recent investigations into the response of the leaf, root and reproductive system to the environment. Monteith's analysis of the response of plants to intercepted radiation is appropriate for analyzing the productivity of bananas and plantains. The banana is sensitive to soil water deficits, and expanding tissues such as emerging leaves and growing fruit are among the first to be affected. As soil begins to dry, stomata close and leaves remain highly hydrated, probably through root pressure. Productivity is affected because of the early closure of stomata. We find the common belief that bananas use large amounts of water does not...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Crop yield; Leaf system; Light; Photoperiod; Photosynthesis; Reproductive system; Root system; Temperature; Water supply.
Ano: 2007
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202007000400013

Phytochemical and physiological changes in Ashwagandha (Withania somnifera Dunal) under soil moisture stress
Provedor de dados: 61
Autores: Shah,Sonal; Saravanan,Raju; Gajbhiye,Narendra Atmaram.
Ashwagandha, commonly known as the Indian Ginseng (Withania somnifera) is an ingredient in many herbal preparations used for healing various ailments. It is cultivated in semi-arid regions of India as rain-fed crop. The response of this crop (cv. JA-134) to progressive soil moisture deficit on growth, physiology and content of phytochemicals was studied. At the end of treatment period, soil water potential (Ψw) decreased to -10.93, -1.15 MPa at 30 cm depth, predawn leaf water potentials were reduced to -0.62 and -0.51 MPa in the severe and moderate stress. Leaf area was reduced by 27.4% and 34.4% in moderate and severe water stress treatment compared to control. Chlorophyll content was reduced by 60% in the severe water stress. Changes in the steroidal...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Medicinal plant; Secondary metabolites content; Soil moisture stress; Withanolide content.
Ano: 2010
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202010000400005

Asymmetrical leaves induced by water deficit show asymmetric photosynthesis in common bean
Provedor de dados: 61
Autores: Souza,Gustavo Maia; Viana,Juliana de Oliveira Fernandes; Oliveira,Ricardo Ferraz de.
In this study we tested the hypothesis that leaf asymmetric growth induced by water deficit in common bean (Phaseolus vulgaris L.) might be correlated with different net photosynthesis rates between the two opposed leaflets (right and left) considering a bilateral symmetric plane. In order to induce developmental instability, the drought-sensitive common bean genotype "Jalo Precoce" was subjected to periods of suspended irrigation during its vegetative growth. Developmental instability was evaluated by measurements of leaflets asymmetry, and the effects of drought on gas exchanges were taken in both symmetrical leaflets (right and left) in relation to the central leaflet. Water deficit induced an increase of 80 % in leaf asymmetry. Net photosynthesis of P....
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Developmental instability; Leaf symmetry; Water deficit.
Ano: 2005
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202005000200005

Changes in growth and superoxide dismutase activity in Hydrilla verticillata L. under abiotic stress
Provedor de dados: 61
Autores: Panda,Sanjib Kumar; Khan,Mohammad Hussain.
A study was made of the role of various heavy metals (chromium, zinc, copper and cadmium) together with the effects of NaCl-salinity, PEG-mediated water stress and temperature on growth and superoxide dismutase (SOD) activity in hydrilla (Hydrilla verticillata L.). Almost all metals studied reduced growth but presented a modulatory effect at lower concentrations. NaCl-salinity, water stress and temperature treatments also reduced growth. SOD activity was inhibited by both chromium and zinc but increased by copper and cadmium. NaCl-salinity increased SOD activity while water stress decreased it. SOD showed thermostability with a higher activity being recorded at 45ºC.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Growth; Heavy metals; NaCl; PEG; Superoxide dismutase; Temperature.
Ano: 2004
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202004000200007

Changes in growth variables and potassium content in leaves of Black Barley in response to NaCl
Provedor de dados: 61
Autores: Abu-Al-Basal,Mariam A.; Yasseen,Bassam T.
Much attention is being focused on the Black barley (Hordeum distichum L.) as a local cultivar offering good model for a cereal crop has traits of resistance to drought and salinity during vegetative growth stages. Although Black was sensitive to salt stress during germination, it developed gradual tolerance with age and proved very tolerant during growth and development stages. The data of study clearly revealed how this cultivar was superior over Arivat (Hordeum vulgare L.) in many physiological aspects such as leaf growth variables (i.e. rate and duration) and processes (i.e. cell division), tiller production and potassium content. Black barley had more tillers, faster rate and longer duration of growth processes which was accompanied with potassium...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Black barley; Hordeum distichum L.; Cell division; Growth rate; Growth duration; Leaf growth; Arivat; Hordeum vulgare L.; Potassium; Salt stress.
Ano: 2009
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202009000400002

Physic nut plants present high mycorrhizal dependency under conditions of low phosphate availability
Provedor de dados: 61
Autores: Balota,Elcio Liborio; Machineski,Oswaldo; Viviane Truber,Priscila; Scherer,Alexandra; Souza,Fabio Suano de.
The physic nut (Jatropha curcas L.) is a perennial tree that occurs naturally in the tropical and subtropical regions of Brazil. Fruits of physic nut present an oil content of 28% on a dry weight basis. Although the plant has adapted to diverse soil conditions such as low fertility, the correction of soil acidity and the addition of fertilizer are essential for highly productive plants. Thus, the response of the physic nut to different soil phosphorus levels (P) and arbuscular mycorrhizal fungi (AMF) inoculation must be characterized. Hence, the objective of the present study was to evaluate the response of physic nut seedlings to arbuscular mycorrhizal fungi (AMF) inoculation at different levels of soil P. Experiment was carried out in a greenhouse...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Mycorrhizal inoculation; Plant growth; Leaf area; Biomass dry matter.
Ano: 2011
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202011000100006

Changes in growth and photosynthetic capacity of cucumber seedlings in response to nitrate stress
Provedor de dados: 61
Autores: Yang,Xiaoyu; Wang,Xiufeng; Wei,Min; Hikosaka,Shoko; Goto,Eiji.
The effects of three nitrate levels - 14(CK), 56(T-1), and 140 mmol L-1 (T-2) - on growth and photosynthetic capacity of cucumber (Cucumis sativus L. cv. Xintaimici) seedlings grown in hydroponic culture were investigated. The results showed that at 12 d after treatment plant height, stem diameter, leaf area, and leaf number of cucumber seedlings were stimulated by 56 mmol L-1 nitrate, whereas were inhibited significantly by 140 mmol L-1 nitrate compared with CK. Short-term stimulation in photosynthetic rate occurred under T-1 treatment, and then recovered to the level of CK. Photosynthetic rate of T-2 seedlings significantly decreased over treatment course with respect to CK. Photosynthetic pigment content of T-1 and T-2 increased during the first 2 d,...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Chlorophyll a fluorescence; Hill reaction; Photosynthetic pigment content; Photosynthetic rate.
Ano: 2009
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202009000400007

Jasmonic acid elicits oxidative defense and detoxification systems in Cucumis melo L. cells
Provedor de dados: 61
Autores: Nafie,Eetezaz; Hathout,Tahany; Al Mokadem,Al Shyma.
This study investigated whether a jasmonic acid (JA) elicitation strategy developed in a conventional cell suspension culture could evoke melon resistance mechanisms, including secondary metabolite production. Twenty one day cultured melon cell suspensions grown in MS1 medium were supplemented with JA at the concentrations of 0.5, 5.0 and 10 µmol. Melon cultures were sampled 24, 48 and 72 h post elicitation to evaluate different defense related factors such as antioxidant enzymes, ascorbate metabolism and phenolic compounds. Results suggest that melon cells respond to JA reprogramming the primary and secondary metabolism which will result in melon plantlets with enhanced resistance against diverse stress conditions through the production of specific...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Ascorbic metabolism; Detoxification enzymes; Peroxidase isozymes; Phenolics profile.
Ano: 2011
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202011000200008

Glutamine enhances competence for organogenesis in pineapple leaves cultivated in vitro
Provedor de dados: 61
Autores: Hamasaki,Regina M.; Purgatto,Eduardo; Mercier,Helenice.
Leaf bases of pineapple cultured on a shoot induction medium (SIM) produced protuberances followed by shoot-buds via direct organogenesis at a frequency of 46 %. When 8 mM glutamine (gln) was a supplement to SIM (SIM8gln), the regeneration rate increased to 70 %, thus suggesting that 8mM gln increased explant competence for organogenesis. Besides this, shoot vigor was strongly enhanced in SIM8gln. Other gln concentrations (16 or 32 mM) evoked a lower frequency of shoot-bud induction and number of regenerated shoots per explant when compared to SIM8gln. In this study, it was defined that explant organogenic commitment to form shoot-buds occurred in the first 7 days of culture on SIM8gln. Thereafter, endogenous indole-3-acetic acid (IAA) and cytokinin (4...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Ananas comosus amino acids auxin; Bromeliaceae cytokinins phytohormones shoot regeneration.
Ano: 2005
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202005000400006

Seeds of Amazonian Fabaceae as a source of new lectins
Provedor de dados: 61
Autores: Fernandes,Andreia V.; Ramos,Márcio V.; Gonçalves,José Francisco C.; Maranhão,Paulo A. C.; Chevreuil,Larissa R.; Souza,Luiz Augusto G.
Seeds from fifty native Amazonian Fabaceae species (representing subfamilies Caesalpinioideae, Mimosoideae and Faboideae) were screened for the presence of new lectins. Their crude protein extracts were assayed for hemagglutinating activity (HA). The protein fractions of Anadenanthera peregrina, Dimorphandra caudata, Ormosia lignivalvis and Swartzia laevicarpa exhibited HA, and this activity was inhibited by galactose or lactose but not by glucose or mannose. The crude extract of S. laevicarpa exhibited HA activity only after ion exchange chromatography, and its lectin was further purified by affinity chromatography on immobilized lactose. Despite the large number of lectins that have been reported in leguminous plants, this is the first description of...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Evolutionary relationships; Plant lectins; Protein-carbohydrate interactions; Swartzia; Tropical Fabaceae.
Ano: 2011
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202011000300008

Establishment of sensitive and resistant variety of tomato on the basis of photosynthesis and antioxidative enzymes in the presence of cobalt applied as shotgun approach
Provedor de dados: 61
Autores: Hasan,Syed Aiman; Hayat,Shamsul; Wani,Arif Shafi; Ahmad,Aqil.
Cobalt (Co) affords both beneficial as well as toxic effects to plants. The present study was performed with an aim to find out the varietal differences among five tomato cultivars against the Co induced changes in growth, photosynthesis, nitrate reductase (E.C.1.6.6.1), carbonic anhydrase (E.C.4.2.1.1), antioxidative enzymes i.e. peroxidase (E.C.1.11.1.7), catalase (E.C.1.11.1.6), superoxide dismutase (E.C.1.15.1.1) and that of proline content. Seeds of tomato (varieties, K-25, NTS-9, NBR-Uday, Sarvodya, and Malti) were soaked in 0, 100, 200 or 300 µM CoCl2 for 0, 4, 8, 12 h (shotgun approach) and sampled at 30 days after sowing. All the varieties showed significantly different response to different treatment combinations. Despite substantial varietal...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Antioxidative enzyme; Carbonic anhydrase; Cobalt; Nitrate reductase; Photosynthesis; Tomato.
Ano: 2011
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202011000300001

New Editor-in-Chief for BJPP
Provedor de dados: 61
Autores: Bressan-Smith,Ricardo.
Tipo: Info:eu-repo/semantics/other
Ano: 2012
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202012000100001

Physiological ecology of cerrado plants: new insights and new approaches
Provedor de dados: 61
Autores: Franco,Augusto C.; Haridasan,Mundayatan; Ferreira,Cristiane da Silva.
Tipo: Info:eu-repo/semantics/article
Ano: 2008
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202008000300001

Transport and detoxification of manganese and copper in plants
Provedor de dados: 61
Autores: Ducic,Tanja; Polle,Andrea.
Heavy metals like Mn and Cu, though essential for normal plant growth and development, can be toxic when present in excess in the environment. For normal plant growth maintenance of metal homeostasis is important. Excess uptake of redox active elements causes oxidative destruction. Thus, uptake, transport and distribution within the plant must be strongly controlled. Regulation includes precisely targeted transport from the macro-level of the tissue to the micro-level of the cell and organelles. Membrane transport systems play very important roles in metal trafficking. This review provides a broad overview of the long distance and cellular transport as well as detoxification and homeostasis mechanisms of Mn and Cu, which are essential micronutrients but...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Copper; Heavy metals; Manganese; Phytoremediation; Transport.
Ano: 2005
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202005000100009

Growth of Indian mustard (Brassica juncea L.) in response to salicylic acid under high-temperature stress
Provedor de dados: 61
Autores: Hayat,Shamsul; Masood,Asim; Yusuf,Mohammad; Fariduddin,Qazi; Ahmad,Aqil.
Pots holding 7 day-old seedlings of Indian mustard (Brassica juncea L.) were subjected to differential temperature stress by exposing plants to 30 or 40ºC for 24 h. Seedlings were sprayed with double distilled water (DDW) or 10-5M salicylic acid (SA) at the 8-day stage and were sampled at 30 DAS. The plants exposed to temperature stress exhibited a significant (p &lt; 0.05) decline in growth, and in levels of chlorophyll, nitrate reductase and carbonic anhydrase activities and photosynthetic parameters. A follow-up treatment with SA protected against the stress generated by temperature and significantly improved the above parameters. Antioxidative enzymes and levels of proline significantly increased in response to SA as well as to temperature stress.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Antioxidative enzymes Carbonic anhydrase Nitrate reductase; Photosynthesis Proline.
Ano: 2009
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202009000300003

Copper in plants
Provedor de dados: 61
Autores: Yruela,Inmaculada.
Copper is an essential metal for normal plant growth and development, although it is also potentially toxic. Copper participates in numerous physiological processes and is an essential cofactor for many metalloproteins, however, problems arise when excess copper is present in cells. Excess copper inhibits plant growth and impairs important cellular processes (i.e., photosynthetic electron transport). Since copper is both an essential cofactor and a toxic element, involving a complex network of metal trafficking pathways, different strategies have evolved in plants to appropriately regulate its homeostasis as a function of the environmental copper level. Such strategies must prevent accumulation of the metal in the freely reactive form (metal detoxification...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Copper homeostasis; Copper transporters; Detoxification; Metalloproteins; Toxicity.
Ano: 2005
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202005000100012

Endogenous auxin and cytokinin contents associated with shoot formation in leaves of pineapple cultured in vitro
Provedor de dados: 61
Autores: Mercier,Helenice; Souza,Beatriz Maia; Kraus,Jane Elizabeth; Hamasaki,Regina Mayumi; Sotta,Bruno.
The in vitro culture of pineapple leaves on a shoot induction medium (SIM) results in the formation of protuberances and further development in shoots, and plantlets. The contents of endogenous indoleacetic acid (IAA) and five cytokinins (Cks), N6(2-isopentenyl)adenine (iP), N6(2-isopentenyl)adenosine (iPR), zeatin (Z), zeatin riboside (ZR) and N6-benzyladenine (BA), present in the basal portion of those leaves, were correlated to the organogenic response that occurs over 15 days of culture. The endogenous auxin/cytokinins ratio was lowest on the 3rd day, mainly due to a strong increase in the iP level. It seems that endogenous iP concentration triggered the induction signal for an organogenic response in pineapple leaf bases. The rise in iP content...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Ananas comosus; Auxin; Bromeliaceae; Cytokinin; Hormone signalling; Plant regeneration.
Ano: 2003
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202003000200006

Anti-oxidative and proteolytic activities and protein profile of laticifer cells of Cryptostegia grandiflora, Plumeria rubra and Euphorbia tirucalli
Provedor de dados: 61
Autores: Freitas,Cleverson D. T. de; Souza,Diego P. de; Araújo,Eliane S.; Cavalheiro,Mariana G.; Oliveira,Luciana S.; Ramos,Márcio V.
In this study, proteins extracted from laticifer cells of three plants were examined by electrophoresis, mass spectrometry (MALDI-TOF) and characterized in respect of proteolytic, chitinolytic and anti-oxidative activities by means of zymography and colorimetric assays. Acidic proteins with molecular masses between 12.5 and 74.5 kDa predominated in laticifers of P. rubra. This profile was not found in laticifers of C. grandiflora and E. tirucalli. The later was poor in respect of proteins. Strong anti-oxidative activity of superoxide dismutase (E.C. 1.15.1.1) was detected in P. rubra and C. grandiflora latices, and to a lesser extent ascorbate peroxidase (E.C. 1.11.1.1) and isoforms of peroxidase were seen. Catalase (E.C. 1.11.1.6) was detected only in...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Catalase; Chitinase; Cysteine proteinase; Latex; Peroxidase.
Ano: 2010
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202010000100002

Plant insulin or glucokinin: a conflicting issue
Provedor de dados: 61
Autores: Xavier-Filho,José; Oliveira,Antônia Elenir A.; Silva,Luciana Belarmindo da; Azevedo,Cassiana Rocha; Venâncio,Thiago Motta; Machado,Olga Lima T.; Oliva,Maria Luiza; Fernandes,Kátia Valevski S.; Xavier-Neto,José.
The presence of insulin in plants is not accepted by the scientific community in general. In this review we discuss this paradigm and retrieve information that strongly suggests that insulin is indeed found in plants. We present results, which indicate that a protein molecule with the same amino acid sequence as bovine insulin is expressed in leguminous plants. Additionally, we provide evidence that proteins associated with insulin signalling pathways in vertebrates are also found in association with insulin-like molecules in plants.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Insulin; Glucokinin; Peptide hormone; Plants; Amino acid sequence; Evolution.
Ano: 2003
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202003000200002

Foliar phosphorus supply and CO2 assimilation in common bean (Phaseolus vulgaris L.) under water deficit
Provedor de dados: 61
Autores: Santos,Mauro G. dos; Ribeiro,Rafael V.; Teixeira,Marcelo G.; Oliveira,Ricardo F. de; Pimentel,Carlos.
Two common bean cultivars were grown in pots under greenhouse conditions. Plants were submitted to a foliar Pi spray two days before suspending irrigation, what enhanced net CO2 assimilation rate of Ouro Negro cultivar but did not change significantly the photosynthesis of Carioca cultivar under both water deficit and rehydration periods. The results revealed that a foliar Pi spray induced an up-regulation of photosynthesis in common bean under mild water deficit, with this effect being genotype-dependent.
Tipo: Info:eu-repo/semantics/other
Palavras-chave: Drought stress; Ortophosphate; Photosynthesis; Water deficit.
Ano: 2006
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202006000300007

Metabolism and root exudation of organic acid anions under aluminium stress
Provedor de dados: 61
Autores: Mariano,Eduardo D.; Jorge,Renato A.; Keltjens,Willem G.; Menossi,Marcelo.
Numerous plant species can release organic acid anions (OA) from their roots in response to toxic aluminium (Al) ions present in the rooting medium. Hypothetically OA complex Al in the root apoplast and/or rhizosphere and thus avoid its interaction with root cellular components and its entry in the root symplast. Two temporal patterns of root OA exudation are observed. In pattern I, OA release is rapidly activated after the contact of the root with Al ions while in pattern II there is a lag phase between the addition of Al and the beginning of OA release. Compounds other than OA have been detected in root exudates and are also correlated with Al resistance in plants. Plant species like buckwheat and tea show mechanisms of Al tolerance, which confer them...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Al resistance; Al toxicity; Anion channels; Root exudates; Transgenic plants.
Ano: 2005
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202005000100013

Endo-beta-mannanase from the endosperm of seeds of Sesbania virgata (Cav.) Pers. (Leguminosae): purification, characterisation and its dual role in germination and early seedling growth
Provedor de dados: 61
Autores: Lisboa,César Gustavo Serafim; Tonini,Patrícia Pinho; Tiné,Marco Aurélio Silva; Buckeridge,Marcos Silveira.
Galactomannans are storage cell wall polysaccharides present in seeds of some legumes. Their degradation is carried out by three hydrolases (alpha-galactosidase (EC 3.2.1.22), endo-beta-mannanase (EC 3.2.1.78) and ß-mannosidase (EC 3.2.1.25)). In the present study we purified and characterised an endo-beta-mannanase from seeds of Sesbania virgata and addressed its role in germination and seedling development. The polypeptide purified by Ion Exchange Chromatography and Affinity Chromatography on Sepharose-Concanavalin A, showed a pH optimum between 3.5 and 5 at 45ºC and high stability at pH 7.8. The low stability at pH 5 appears to be associated with isoelectric precipitation, in view of the pI of the enzyme being 4.5. The purified enzyme is a glycoprotein...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Sesbania virgata; Endo-beta-mannanase; Galactomannan; Germination; Leguminosae.
Ano: 2006
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202006000200003

Reproductive physiology of mango
Provedor de dados: 61
Autores: Davenport,Thomas L.
Mango flowering involves hormonal regulation of shoot initiation and induction events resulting in reproductive shoot formation. A balance or ratio of endogenously regulated phytohormones, thought to be auxin from leaves and cytokinins from roots, appears to govern the initiation cycle independently from inductive influences. Induction of reproductive or vegetative shoots is thought to be governed by the ratio of a temperature-regulated florigenic promoter and an age regulated vegetative promoter at the time of shoot initiation. Management of off-season flowering in mango trees is being accomplished in the tropics by successfully synchronizing shoot initiation through tip pruning and use of nitrate sprays coupled with management of the stem age to induce...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Auxin; Cytokinin; Flowering management; Fruiting; Hormones; Mangifera indica.
Ano: 2007
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202007000400007

Recent advances in aluminum toxicity and resistance in higher plants
Provedor de dados: 61
Autores: Vitorello,Victor Alexandre; Capaldi,Flávia Regina; Stefanuto,Vanderlei Antonio.
Aluminum toxicity is a major soil constraint to food and biomass production throughout the world. Considerable advances in the understanding of the mechanism of resistance involving exudation of organic acids have been made in recent years. However, despite intense research efforts, there are many aspects of Al toxicity that remain unclear. This article reviews the features of the chemistry of Al relevant to its toxicity followed by an examination of the mechanisms of toxicity and resistance. Emphasis, however, is given to the mechanisms of Al toxicity, since resistance has been covered recently by several reviews. Some topics which are specifically discussed in this review are: a) The possible role of cellular effects of low pH in Al toxicity, which has...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Al uptake and localization; Cell wall; Cytoskeleton; Differential sensitivity to Al; Low pH; Acidity; Plasma membrane.
Ano: 2005
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202005000100011

Use of the QTL approach to the study of soybean trait relationships in two populations of recombinant inbred lines at the F7 and F8 generations
Provedor de dados: 61
Autores: Vieira,Antonio José Dias; Oliveira,Dario Alves de; Soares,Taís Cristina Bastos; Schuster,Ivan; Piovesan,Newton Deniz; Martínez,Carlos Alberto; Barros,Everaldo Gonçalves de; Moreira,Maurílio Alves.
This work aimed to identify the quantitative trait loci (QTL) associated with photosynthesis and growth and productivity traits of soybean and to study possible associations between these traits by the analysis of coincidence of QTL in linkage groups (LGs). Thus, populations of recombinant inbred lines (RILs) of the F7 and F8 generations derived from the cross between the varieties BARC-8 and Garimpo were used. The traits evaluated were net assimilation rate of CO2 under saturating light (Asat), potential photosynthesis rate (Pmax), leaf area (A), specific leaf area (SLA), specific leaf nitrogen (N); root (W R), nodule (W N), stem (W ST), leaf (W L), pod (W P) and plant dry mass (W T); nodule (nN), seed (n s), and pod number (nP); seed fresh mass per plant...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Glycine max; Correlation; Genes; Photosynthesis; Quantitative trait loci.
Ano: 2006
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202006000200004

Ultrastructure and biochemical traits of bread and durum wheat grains under heat stress
Provedor de dados: 61
Autores: Dias,Ana S.; Bagulho,Ana S.; Lidon,Fernando C.
The yield and grain quality (as well as technological traits) of two heat-stressed genotypes of bread (Triticum aestivum L.) and durum wheat (Triticum turgidum subsp. durum) having different tolerance to high temperatures after anthesis were investigated. Heat stress, during grain filling, triggered grain shrinkage with a reduced weight and ultrastructural changes in the aleurone layer and in the endosperm cells. Heat stress also decreased the sedimentation index SDS, an effect associated with increased protein content in the grain but with decreased levels of essential amino acids. Although the responses to heat stress were similar among the Triticum genotypes, it is further suggested that during grain filling, high temperatures might affect gluten...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Grain weight; Grain quality; High temperature; Triticum aestivum; Triticum turgidum subsp. durum.
Ano: 2008
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202008000400008

An overview of preharvest factors influencing mango fruit growth, quality and postharvest behaviour
Provedor de dados: 61
Autores: Léchaudel,Mathieu; Joas,Jacques.
Mango, a tropical fruit of great economic importance, is generally harvested green and then commercialised after a period of storage. Unfortunately, the final quality of mango batches is highly heterogeneous, in fruit size as well as in gustatory quality and postharvest behaviour. A large amount of knowledge has been gathered on the effects of the maturity stage at harvest and postharvest conditions on the final quality of mango. Considerably less attention has been paid to the influence of environmental factors on mango growth, quality traits, and postharvest behaviour. In this paper, we provide a review of studies on mango showing how environmental factors influence the accumulation of water, structural and non-structural dry matter in the fruit during...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Environmental conditions; Fruit load; Irrigation; Shelf life; Size; Taste.
Ano: 2007
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202007000400004

In memoriam to Alvim and Maestri
Provedor de dados: 61
Autores: Bressan-Smith,Ricardo; Façanha,Arnoldo Rocha.
Tipo: Info:eu-repo/semantics/other
Ano: 2011
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202011000100001

Effects of prescribed fires on the survival and release of seeds of Kielmeyera coriacea (Spr.) Mart. (Clusiaceae) in savannas of Central Brazil
Provedor de dados: 61
Autores: Cirne,Paulo; Miranda,Heloisa Sinátora.
Effects of prescribed fires on survival and release of seeds of the woody species Kielmeyera coriacea (Clusiaceae) were investigated in two plots of cerrado sensu stricto, a savanna vegetation of Central Brazil. The first plot was burnt in June, at the beginning of the dry season, and the second in August, in the middle of the dry season. Seed survival was measured after fire in both areas and related to internal and external fruit temperatures measured during the June fire. The proportion of open fruits per individual of K. coriacea was also assessed at two-week intervals. Maximum external temperatures during fire (393 to 734ºC) were strongly reduced inside the fruits (61 to 63ºC). Before the June fire, the majority of the fruits were closed in both...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Cerrado; Fire season; Fruit temperature; Germination; Seed release.
Ano: 2008
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202008000300004

An overview of the Brazilian Journal of Plant Physiology: we need a push!
Provedor de dados: 61
Autores: Mazzafera,Paulo; Azevedo,Ricardo Antunes de.
Tipo: Info:eu-repo/semantics/other
Ano: 2012
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202012000400001

Photosynthetic performance in jack bean [Canavalia ensiformis (L.) D.C.] under drought and after rehydration
Provedor de dados: 61
Autores: Zanella,Fábio; Watanabe,Tania Misae; Lima,Ana Lúcia da Silva; Schiavinato,Marlene Aparecida.
The effects of drought and rehydration on Canavalia ensiformis (L.) D.C. (jack bean) plants were evaluated using the following gas exchange parameters: net carbon assimilation rate (A), stomatal conductance (g s), Ci/Ca ratio and transpiration rate (E); chlorophyll a fluorescence: Fv/Fm and Fv/F0 ratio. The plants were cultivated under greenhouse conditions and after 30 days from the emergence, irrigation was suspended in the plants submitted to drought, to obtain the following predawn leaf water potential (psipd): -0.40 MPa (control), -1.00 MPa (moderate drought) and -2.30 Mpa (severe drought). Afterwards, the gas exchange and fluorescence analysis were initiated , and 24 h after rehydration the same analyses were repeated. The A, E, g s and Ci/Ca values...
Tipo: Info:eu-repo/semantics/other
Palavras-chave: Fluorescence; Moderate drought; Photosynthesis; Severe drought; Stomatal conductance.
Ano: 2004
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202004000300008

Photosynthetic capacity of three phytoplanktonic species measured by a pulse amplitude fluorometric method
Provedor de dados: 61
Autores: Figueredo,Cleber Cunha; Giani,Alessandra; Lemos Filho,José Pires.
During photosynthesis, absorbed energy that is not used in photochemical reactions dissipates as fluorescence. Fluorescence provides important information on the physiological conditions of the studied organisms and its measurement is widely used by plant physiologists and can be valuable in phytoplankton studies. We describe a method adapting a plant fluorometric equipment to measure the photosynthetic capacity of microalgae. Unialgal cultures of three planktonic chlorophytes were exposed to 3(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU), an inhibitor of photosystem II, at concentrations of 0.1, 1.0 and 10.0 µmol.L-1. Estimates were made of photosynthetic parameters, including operational and potential photosystem II quantum yield and electron transport...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Chlorophytes photosynthesis; Electron Transport Rate; Phytoplankton.
Ano: 2009
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202009000300001

Seed germination responses of the medicinal herb Centella asiatica
Provedor de dados: 61
Autores: Devkota,Anjana; Jha,Pramod Kumar.
The effect of several environmental factors on germination of medicinal herb Centella asiatica was investigated. Freshly harvested seeds of C. asiatica did not germinate even after gibberellic acid (GA3) treatment and exposure to different treatments with light qualities, while two-three months old seeds exhibited germination (82%) without pre-treatment at warm environment (25 -30ºC). GA3 treatment induced germination by two weeks earlier than in control. Germination was significantly (p=0.001) higher in red and white light than in blue and far red light. In addition, germination of C. asiatica was sensitive towards the salt stress and was significantly inhibited at 6500 ppm NaCl. The leaf leachates from invasive weeds Chromolaena odorata, Ageratum...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: 2; 3; 5-triphenyltetrazolium chloride Salinity Leaf leachate weeds gibberellic acid.
Ano: 2010
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202010000200008

Photo-oxidative stress in coconut seedlings: early events to leaf scorching and seedling death
Provedor de dados: 61
Autores: Naresh,Kumar S.; Kasturi Bai,K.V.
Experiments were conducted on coconut seedlings to delineate events of photo-oxidative stress damage. Studies on chlorophyll fluorescence indicated a clear case of excess light energy under high light conditions causing stress to coconut seedlings raised under coconut palms. Quantum yield of photo-chemistry of leaflets exposed to high light was significantly less than those under shade. Seedlings exposed to high light and then shifted to shade have shown significant improvement in quantum yield. Excess light energy harvested by chlorophyll antenna caused high non-photochemical quenching resulting in production of biologically toxic super oxide, hydrogen peroxide and hydroxyl radicals. It is apparent that photoinhibition of photosynthesis takes place due to...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Cocos nucifera; Chlorophyll fluorescence; Oxidative stress; Photosynthesis; Lipid peroxidation; Gas exchange; Proteins.
Ano: 2009
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202009000300006

Apoplasm hydrostatic pressure on growth of cylindrical cells
Provedor de dados: 61
Autores: Pessoa,José Dalton Cruz; Calbo,Adonai Gimenes.
According to the model frequently used as reference, plant cell growth occurs only when turgor surpasses a threshold. This model was proposed considering a cylindrical cell of constant wall thickness immerged in a water solution, with viscoelastic behaviour, hydraulic conductivity, variable extensibility, and unidirectional elongation. The author, Lockhart (1965), did not consider the effects of apoplasm hydrostatic potential, a subject treated later by Calbo and Pessoa (1994) who argued that this component of cell potential would interfere with cell growth rate. To evaluate this effect, where possible the same deductive procedures as those employed by Lockhart were used here, which resulted in a set of equivalent equations for cell growth, turgor and...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Apoplasm; Cell wall; Growth; Lockhart; Model; Plant.
Ano: 2004
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202004000100003

Photochemical efficiency in bean plants (Phaseolus vulgaris L. and Vigna unguiculata L. Walp) during recovery from high temperature stress
Provedor de dados: 61
Autores: Costa,Ernany Santos; Bressan-Smith,Ricardo; Oliveira,Jurandi Gonçalves de; Campostrini,Eliemar; Pimentel,Carlos.
Bean (Phaseolus vulgaris L., cv. Carioca and cv. Negro Huasteco) and cowpea plants (Vigna unguiculata L. Walp cv. Epace 10) were grown in a growth chamber with PPF at leaf level of 200 mumol.m-2.s-1 and air temperature 25 + 1 ºC. The first fully expanded pair of leaves of 12-day-old plants was submitted to high temperature stress (25, 30, 35, 40, 45 and 48 ºC) for 1.5 h. The photochemical efficiency of PSII during recovery was monitored by means of chlorophyll a fluorescence at six different times (0.5, 1, 2, 4, 24, and 48 h) after stress, at 25 ºC, using a modulated fluorimeter. Increasing temperature promoted an increase in Fphi at 45 ºC, possibly associated with dissociation of the light harvesting complex from the reaction centre of PSII, but a...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Chlorophyll a fluorescence; Heat stress; Photosynthesis.
Ano: 2002
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202002000200004

Bioactive compounds and antioxidant capacities in the flavedo tissue of two citrus cultivars under low temperature
Provedor de dados: 61
Autores: Mohammadian,Mansour Afshar; Mobrami,Zeinab; Sajedi,Reza Hasan.
Antioxidants production is amongst the physiological responses of plants to protect their tissues from oxidative damages caused by chilling and freezing stresses. Indeed, cold tolerance of plants is related to production of reactive oxygen species (ROS) scavengers to combat oxidative stress. In this study, two citrus cultivars including Citrus sinensis 'Siavaraz' and Citrus limon 'Lisbon' grown at the north of Iran were examined to compare antioxidants changes including total flavonoid, total phenol and total antioxidant capacities (TAC) in the flavedo tissue of the fruits under various low temperature treatments of control (15 ºC), 3, 0, -3 and -6 ºC. The results indicated that total flavonoid content and TAC in Citrus limon 'Lisbon' was significantly...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Antioxidant capacity; Citrus; Low temperature treatment.
Ano: 2011
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202011000300004

Cadmium-Zinc interactions in a hydroponic system using Ceratophyllum demersum L.: adaptive ecophysiology, biochemistry and molecular toxicology
Provedor de dados: 61
Autores: Aravind,Parameswaran; Prasad,Majeti Narasimba Vara.
The interaction between an essential micronutrient, Zn and a toxic non-essential element, Cd has been comprehensively reviewed based on our experiments conducted with Ceratophyllum demersum L. in a hydroponic system. Since Cd and Zn belong to the group IIB transition elements and show similarities in chemistry, geochemistry and environmental properties, it would be one of the elemental pairs of choice to investigate metal-metal interactions. Evidence in support of the protective role of Zn against Cd toxicity in Ceratophyllum demersum L. is presented in this review. Based on our experimental results, we conclude that the antioxidant properties of Zn play an important role in counteracting Cd toxicity.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Antagonistic; Antioxidant; Enzyme conformation; Metal interactions; Redox pool.
Ano: 2005
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202005000100002

Phytoremediation: green technology for the clean up of toxic metals in the environment
Provedor de dados: 61
Autores: Gratão,Priscila Lupino; Prasad,Majeti Narasimha Vara; Cardoso,Patrícia Felippe; Lea,Peter John; Azevedo,Ricardo Antunes.
The contamination of the environment by toxic metals poses a threat for "Man and biosphere", reducing agricultural productivity and damaging the health of the ecosystem. In developed nations, this problem is being addressed and solved to some extent by using "green technology" involving metal tolerant plants, to clean up the polluted soils. The use of naturally occurring metal tolerant plants and the application of genetic manipulation, should hasten the process of transferring this technology from laboratory to field. Therefore, it is essential to investigate and understand how plants are able to tolerate toxic metals and to identify which metabolic pathways and genes are involved in such a process. Recent advances in knowledge derived from the "omics",...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Hyperaccumulator plants; Phytoremediation; Toxic metals.
Ano: 2005
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202005000100005

Primary metabolism components of seeds from Brazilian Amazon tree species
Provedor de dados: 61
Autores: Gonçalves,José Francisco de C.; Fernandes,Andreia V.; Oliveira,Antonio Fernando M.; Rodrigues,Lílian F.; Marenco,Ricardo A.
The contents of the main components of the primary metabolism (soluble sugars, starch, proteins, oils, fatty acids) and minerals (P, Ca, Mg, K, Fe, Zn, Mn, Cu) were characterized in seeds of five Brazilian Amazon tree species (Andira parviflora, Bertholletia excelsa, Helicostylis tomentosa, Hymenaea parviflora, and Parkia pendula). Soluble sugar contents were high in P. pendula seeds (14 %), whereas starch predominated in A. parviflora seeds (58.7 %). A. parviflora and H. parviflora seeds were rich in proteins (35.1 % and 32.4 %, respectively). The oil contents ranged from 1.4 % in A. parviflora to 70.7 % in B. excelsa. Only B. excelsa and P. pendula seeds may be considered oilseeds, with 70.7 % and 28.4 % oil, respectively. The fatty acid compositions...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Fatty acids; Minerals; Oils; Proteins; Soluble sugars; Starch.
Ano: 2002
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202002000200009

Growth, photosynthate partitioning and fructan accumulation in plants of Vernonia herbacea (Vell.) Rusby under two nitrogen levels
Provedor de dados: 61
Autores: Cuzzuol,Geraldo Rogério Faustini; Carvalho,Maria Angela Machado de; Zaidan,Lilian B.P.
The effect of two nitrogen concentrations on fructan accumulation and plant growth was analysed in plants of Vernonia herbacea during a year period. Plants of this species accumulate inulin-type fructans in the underground reserve organs (rhizophores). The plants were cultivated in glasshouse conditions and received weekly nutrient solutions containing 1.3 mmol.L-1 NO3- (N-limited) or 10.7 mmol.L-1 NO3- (N-sufficient). Plants treated with N-sufficient solution presented an increase in total growth with higher biomass, more but smaller leaves resulting in higher total leaf area, higher net assimilation rate, specific leaf mass and higher biomass allocation to aerial organs. In addition, these plants presented higher contents of reducing sugars and lower...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Asteraceae; Cerrado; Fructans; Underground reserve organs.
Ano: 2005
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202005000400008

Soil drying and rewatering applied at three grain developmental stages affect differentially growth and grain protein deposition in wheat (Triticum aestivum L.)
Provedor de dados: 61
Autores: Beltrano,José; Ronco,Marta Guillermina; Arango,María Cecilia.
Water deficits cause large yield losses in wheat. Although anthesis is generally considered the most vulnerable period, water deficit during grain filling can also cause yield losses. The objective of this study was to investigate the effect of water stress and rewatering, at three different grain developmental stages, on physiological and grain filling parameters and on yield components. Wheat plants were subjected to water deficit and rewatering at the watery ripe, milk and soft dough stages. In the flag leaf, water stress decreased the relative water content, the chlorophyll and protein content and increased the leakage of solutes, at all three studied grain filling stages. Water stress at the watery ripe and milk stages reduced the final grain dry mass...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Grain filling; Growth rate; Logistic model; Protein profile; Water stress.
Ano: 2006
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202006000200011

Two-dimensional gel electrophoretic protein profile analysis during seed development of Ocotea catharinensis: a recalcitrant seed species
Provedor de dados: 61
Autores: Dias,Leonardo L.C.; Balbuena,Tiago S.; Silveira,Vanildo; Santa-Catarina,Claudete; Schevchenko,Andrej; Floh,Eny I. S.
The aim of the present work was to characterize changes in the protein profile throughout seed development in O. catharinensis, a recalcitrant species, by two-dimensional gel electrophoresis. Protein extraction was undertaken by using a thiourea/urea buffer, followed by a precipitation step with 10% TCA. Comparative analysis during seed development showed that a large number of proteins were exclusively detected in each developmental stage. The cotyledonary stage, which represents the transition phase between embryogenesis and the beginning of metabolism related to maturation, presents the highest number of stage-specific spots. Protein identification, through MS/MS analysis, resulted in the identification of proteins mainly related to oxidative metabolism...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: 2-DE; Comparative proteomics; Embryo development; Storage protein; Lauraceae.
Ano: 2010
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202010000100003

Coffee carbohydrates
Provedor de dados: 61
Autores: Redgwell,Robert; Fischer,Monica.
This review summarises recent advances in the chemistry, physiology and molecular properties of coffee carbohydrates with a particular focus on the cell wall polysaccharides. The results of detailed chemical studies have demonstrated novel structural features of both the galactomannans and the arabinogalactan polysaccharides of the green and roasted coffee bean. For the first time immunological probes based on monoclonal antibodies for specific polysaccharide epitopes were used to reveal the patterns of distribution of the galactomannans, arabinogalactans and pectic polysaccharides in the coffee bean cell wall. Finally, the results of physiological and molecular studies are presented which emphasise the growing awareness of the potential role the metabolic...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Coffea; Cell wall; Beverage quality; Seed.
Ano: 2006
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202006000100012

Antioxidant and other biochemical defense responses of Macrotyloma uniflorum (Lam.) Verdc. (Horse gram) induced by high temperature and salt stress
Provedor de dados: 61
Autores: Naji,Khalid Mohammed; Devaraj,V. R.
High temperature and salinity are the major ecological factors challenging crop productivity in the arid and semiarid regions of the world. Effects of high temperature (43-45°C) and salt stress (0.6 M) on Macrotyloma uniflorum (Lam.) Verdc. (Horse gram), were evaluated in terms of antioxidants and antioxidant enzymes. Both treatments caused typical stress responses in this tropical leguminosae. Oxidative stress indicators such as H2O2, TBARS, and proline were significantly elevated. Similarly, the antioxidant enzymes superoxide dismutase (SOD; EC 1.15.1.1), guaiacol peroxidase (POX; EC 1.11.1.7) and acid phosphates (AP; EC 3.1.3.2) were significantly elevated while catalase (CAT; EC 1.11.1.6) was reduced. These treatments had contrasting effects on...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Antioxidant enzymes; Horse gram; Isozymes; Oxidative stress; Salinity; Stress markers.
Ano: 2011
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202011000300002

Improved tolerance of wheat plants (Triticum aestivum L.) to drought stress and rewatering by the arbuscular mycorrhizal fungus Glomus claroideum: effect on growth and cell membrane stability
Provedor de dados: 61
Autores: Beltrano,José; Ronco,Marta G.
The aim of this paper was to investigate the contribution of the arbuscular mycorrhizal fungus Glomus claroideum to drought stress tolerance in wheat plants grown under controlled conditions in a growth chamber, and subjected to moderate or severe water stress and rewatering. Water stress tolerance was determined through total dry weight, leaf relative water content, leakage of solutes and leaf chlorophyll and protein concentrations in mycorrhizal and non-mycorrhizal wheat plants. Total dry weight and leaf chlorophyll concentrations were significantly higher in mycorrhizal plants after moderate or severe water stress treatments compared with non-mycorrhizal ones. Electrolyte leakage was significantly lower in water-stressed inoculated plants. Compared to...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Mycorrhizae; Relative water content; Rewatering; Solute leakage; Water deficit.
Ano: 2008
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202008000100004

Supplemental Ca2+ does not improve growth but it affects nutrient uptake in NaCl-stressed cowpea plants
Provedor de dados: 61
Autores: Guimarães,Francisco Valderez Augusto; Lacerda,Claudivan Feitosa de; Marques,Elton Camelo; Abreu,Carlos Eduardo Braga de; Aquino,Boanerges Freire de; Prisco,José Tarquinio; Gomes-Filho,Enéas.
The growth and nutrient assimilation was evaluated in CaCl2- and CaSO4-supplemented cowpea plants subjected to salt stress (75 mM NaCl). The salinity significantly reduced the cowpea vegetative growth. The addition of CaCl2 in the growth medium did not significantly affect plant growth, while for the CaSO4, the beneficial effects of Ca2+ were moderate. Salinity increased the Na+, K+, Cl-, N and P content in the plants, however it decreased the content of Ca2+ and Mg2+. Increases in Ca2+ concentration in the nutrient solution caused decreases in the Na+ and Mg2+ contents and increases in Ca2+, K+, P, and Cl- contents. The supplemental Ca2+ may alleviate the Na+ toxicity and may improve nutritional and ionic balance in cowpea, but it cannot overcome the...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Calcium; Mineral nutrition; Salinity; Vigna unguiculata.
Ano: 2012
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202012000100003

Ecophysiological factors underpinning productivity of Hevea brasiliensis
Provedor de dados: 61
Autores: Rodrigo,V.H.L.
High land productivity is a must for any commercial cultivation including Hevea brasiliensis (rubber). Also, the high demand for natural rubber has placed great pressure on expanding rubber cultivation to new and non-traditional areas. Understanding the ecophysiological principles behind the measures of productivity improvements is vital for wide application of these measures and to assess their sustainability. This review discusses the ecophysiological principles and tools used, along with the measures taken, to address productivity needs in terms of: genotype selection, determination of optimum planting density, and establishment of intercropping systems. Breeding for high yields and selection of suitable genotypes for different growing conditions are a...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Rubber; Genotype selection; Intercropping; Planting density; Physiology.
Ano: 2007
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202007000400002

The effect of zinc supply and succinate treatment on plant growth and mineral uptake in pea plant
Provedor de dados: 61
Autores: Stoyanova,Zlatimira; Doncheva,Snejana.
The influence of succinate treatment on Zn toxicity was investigated using plant growth and mineral uptake as stress indicators. Pea plants (Pisum sativum L., cv. Citrine) were treated with various Zn concentrations (0.67 to 700 muM Zn) in the presence and absence of 0.2 mM Na-succinate. Plants pre-treated with succinate and then exposed to Zn exhibited higher dry root, stem and leaf weight than the plants treated with Zn alone. An increase in Zn supply resulted in a decrease in the concentrations of Ca, Mg, P in the roots and an increase of Ca and N levels in the stems and leaves. The amount of Zn in the roots, stems and leaves increased with greater Zn rates. The succinate treatment increased P in the roots but did not affect the Ca, N and Mg contents in...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Succinate; Zinc toxicity amelioration.
Ano: 2002
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202002000200005

Cytology, biochemistry and molecular changes during coffee fruit development
Provedor de dados: 61
Autores: De Castro,Renato D.; Marraccini,Pierre.
In commercial coffee species (Coffea arabica and Coffea canephora), fruit development is a lengthy process, characterized by tissue changes and evolutions. For example, soon after fecundation and up to mid development, the fruit is mainly constituted of the pericarp and perisperm tissue. Thereafter, the perisperm gradually disappears and is progressively replaced by the endosperm (true seed). Initially present in a "liquid" state, the endosperm hardens as it ripens during the maturation phase, as a result of accumulation of storage proteins, sucrose and complex polysaccharides representing the main reserves of the seed. The last step of maturation is characterized by the dehydration of the endosperm and the color change of the pericarp. Important...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Coffea spp; Bean development; Cell cycle; Endosperm; EST; Gene expression; Pericarp; Perisperm.
Ano: 2006
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202006000100013

An instrumental set up for seed germination studies with temperature control and automatic image recording
Provedor de dados: 61
Autores: Teixeira,Pedro C.N.; Coelho Neto,José A.; Rocha,Humberto; Oliveira,Juracy M. de.
This paper describes a new instrumental methodology proposed for the study of seed germination which can be applied to germination physiology, agriculture and forest restoration. This instrument performs the recording of images of germinating seeds through the use of a flat-bed scanner coupled to a computer, where a specific program commands the capture of these images at predetermined time intervals. These images are archived for posterior analysis. The device allows the collection of data and the elaboration of germination curves with high accuracy. Furthermore, the device permits the study of seed germination over a broad range of temperatures as well as the easy application of chemical agents to the seeds in order to study their influence on the...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Digital image; Lactuca sativa; Scanner; Siegel's test; Thermal gradient tables.
Ano: 2007
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202007000200002

Energetic flux and performance index in copaiba (Copaifera multijuga Hayne) and mahogany (Swietenia macrophylla King) seedlings grown under two irradiance environments
Provedor de dados: 61
Autores: Gonçalves,José F.C.; Santos Jr.,Ulysses M.; Nina Jr.,Adamir R.; Chevreuil,Larissa R.
Plant adaptation under conditions of limited irradiance can be investigated by their efficiency while using the available energy with a minimal thermodynamic energy loss. For this reason, we compared the energetic fluxes and the performance index (PI ABS) in copaiba (Copaifera multijuga) and mahogany (Swietenia macrophyla) seedlings under both sunlight and shade. The experiment was carried out in Manaus (3º8'S, 59º52'W), Amazonas State, Brazil. The fluorescence transients were obtained in intact and healthy leaves using a Plant Efficiency Analyser (PEA) between 1200 h and 1300 h. Using the O-J-I-P test, the following parameters were calculated: 1) density of reaction centers per cross section (RC/CS), 2) maximum quantum yield for primary photochemistry of...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Chlorophyll a fluorescence; Energy fluxes in photosystem II; Light acclimation; O-J-I-P transients; Tropical tree species.
Ano: 2007
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202007000300001

Chlorophyll fluorescence in rice: probing of senescence driven changes of PSII activity on rice varieties differing in grain yield capacity
Provedor de dados: 61
Autores: Falqueto,Antelmo R.; Silva,Fabio S. P.; Cassol,Daniela; Magalhães Júnior,Ariano M.; Oliveira,Antônio C.; Bacarin,Marcos A.
With Japonica rice BRS Firmeza and indica rice BRS Pelota (low and high grain yield, respectively) as materials, Chl content and Chl a fluorescence parameters in flag leaves from the heading to mature grain stage were investigated. The Chl content and the Chl a fluorescence were measured using a portable chlorophyll meter CL-01 and portables fluorometer Handy-PEA and FMS-2 (Hansatech, Kings Lynn, UK), respectively. All measurements were taken on middle part of the flag leaves (n = 10). The results showed that the Chl content and Chl a fluorescence parameters declined after full expansion of flag leaves in both rice cultivars. However, these biochemical and photochemical parameters did not show similar changing pattern and the behavior of flag leaves...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: JIP-test; Non-photochemical quenching coefficient; Oryza sativa; Performance index; PSII photochemical efficiency; Stay green mutant rice.
Ano: 2010
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202010000100004

Salinity effects on leaf ion composition and salt secretion rate in Avicennia germinans (L.) L.
Provedor de dados: 61
Autores: Suárez,Nathalie; Medina,Ernesto.
The effect of salinity on leaf water relations, and rate and ionic composition of leaf secretion was investigated in plants of Avicennia germinans growing under controlled salinity conditions. Increases in salinity from 0 to 940 mol NaCl m-3 reduced the predawn water potential from -0.56 to -4.16 MPa and the solute potential from -2.27 to -4.48 MPa, whereas the pressure potential remained positive in all treatments. Compared to the control, at 940 mol NaCl m-3 Na+ and Cl- concentrations of leaf sap increased 19 and 7 times, respectively. With the addition of salt the main ions accumulated in leaves were Na+ and Cl- whereas plants grown without salt accumulated K+ in leaves at levels similar to those of Na+ with salt treatments. Secretion rates of Na+ and...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Ion concentration; Mangroves; Na+/K+ ratio; Salt stress; Water relations.
Ano: 2008
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202008000200005

Structure, organization, and functions of cellulose synthase complexes in higher plants
Provedor de dados: 61
Autores: Festucci-Buselli,Reginaldo A.; Otoni,Wagner C.; Joshi,Chandrashekhar P.
Annually, plants produce about 180 billion tons of cellulose making it the largest reservoir of organic carbon on Earth. Cellulose is a linear homopolymer of beta(1-4)-linked glucose residues. The coordinated synthesis of glucose chains is orchestrated by specific plasma membrane-bound cellulose synthase complexes (CelS). The CelS is postulated to be composed of approximately 36 cellulose synthase (CESA) subunits. The CelS synthesizes 36 glucose chains in close proximity before they are further organized into microfibrils that are further associated with other cell wall polymers. The 36 glucose chains in a microfibril are stabilized by intra- and inter-hydrogen bonding which confer great stability on microfibrils. Several elementary microfibrils come...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Cellulose biosynthesis; Cellulose synthase (CESA); Cellulose synthase complex (CelS); Microfibril.
Ano: 2007
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202007000100001

The effect of arbuscular mycorrhizal fungal isolates on the development and oleoresin production of micropropagated Zingiber officinale
Provedor de dados: 61
Autores: Silva,Maicon F. da; Pescador,Rosete; Rebelo,Ricardo A.; Stürmer,Sidney L.
We have investigated the effects of phosphate fertilization and inoculation with isolates of arbuscular mycorrhizal fungi Scutellospora heterogama SCT120E, Gigaspora decipiens SCT304A, Acaulospora koskei SCT400A, Entrophospora colombiana SCT115, and an assemblage (Mix) of all four isolates on growth, development and oleoresin production of micropropagated Zingiber officinale. After 120 and 210 d of growth, the Mix and phosphorus addition significantly increased shoot height relative to control plants. Phosphorus addition was the only treatment resulting in significantly large shoot dry biomass relative to control after 120 d. No statistical differences were observed between treatments for shoot dry biomass after 210 d and for fine and coarse root biomass...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Fungal assemblage; Ginger; Oleoresin; Secondary metabolites.
Ano: 2008
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202008000200004