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| 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 |
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| 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 |
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| 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 |
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| 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 |
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| 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 |
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| 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 |
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| 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 |
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| 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 |
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| 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<FONT FACE=Symbol>®</FONT>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 |
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| 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 |
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| 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 |
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| 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 |
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