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