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| Registros recuperados: 360 | |
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| 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 |
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| 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 |
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| 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 |
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| 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 |
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| 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 |
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| 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 |
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| 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 |
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| 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 |
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| 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 |
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| 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 |
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| 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 |
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| 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 |
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| Registros recuperados: 360 | |
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