Artigos
URI permanente para esta coleçãohttps://locus.ufv.br/handle/123456789/11847
Navegar
6 resultados
Resultados da Pesquisa
Item Lipoxygenase activities during development of root and nodule of soybean(Pesquisa Agropecuária Brasileira, 2004-07) Oliveira, Maria Goreti de Almeida; Moreira, Maurilio Alves; Junghans, Tatiana GóesThe objective of this work was to evaluate root and nodule soybean lipoxygenases in Doko cultivar and in a near isogenic line lacking seed lipoxygenases, inoculated and uninoculated with Bradyrhizobium elkanii. The lipoxygenase activities from roots collected at 3, 5, 9, 13, 18 and 28 days post-inoculation and from nodules collected at 13, 18 and 28 days post-inoculation were measured. The pH-activity profiles from root and nodules suggested that the lipoxygenases pool expressed in these organs from Doko cultivar and triple-null near isogenic lines are similar. The root lipoxygenase activity of Doko and triple-null lines, inoculated and uninoculated, reduced over time. The highest lipoxygenase activity observed at the beginning of root formation suggests the involvement of this enzyme in growth and development of this organ. However, for nodules an expressive increase of lipoxygenase activity was noticed 28 days post-inoculation. Root and nodule showed, at least, two mobility groups for lipoxygenases in immunoblottings, with approximately 94 and 97 kDa.Item Função bioquímica da via daslipoxigenases em plantas de soja submetidas ao ataque de mosca-branca (Bemisia argentifolii)(Ciência e Agrotecnologia, 2004-03) Silva, Francine Barbosa; Oliveira, Maria Goreti de A.; Brumano, Maria Helena N.; Pires, Christiano Vieira; Almeida, Fabrício Tadeu de; Oliveira, Joel Antônio; Pilon, Anderson Martins; Silva, Carlos Henrique Osório; Moreira, Maurilio AlvesNeste trabalho, avaliou-se a capacidade da planta de soja de uma cultivar comercial, IAC-100, e de um genótipo IAC- 100 TN que apresenta ausência de lipoxigenases nas sementes de responderem ao ataque de mosca-branca (Bemisia argentifolii) pela via das Lipoxigenases. Foi realizada a caracterização cinética do pool de lipoxigenases. Os valores de KMapp decresceram nas plantas atacadas, sugerindo uma alteração no pool de lipoxigenases foliares. Valores similares de KMapp, entre os genótipos, indicam que a remoção de lipoxigenases de sementes não interferiram na expressão de lipoxigenases em folhas. Ocorreu aumento significativo na produção de inibidores de proteases. Com esses resultados, infere-se que a produção de inibidores de proteases está envolvida no mecanismo de defesa de soja ao ataque da mosca-branca.Item Efeito da aplicação foliar de ácidos graxos na "via das lipoxigenases" de plantas de soja(Química Nova, 2002-11) Batista, Rosa Bárbara; Oliveira, Maria Goreti de Almeida; Pires, Christiano Vieira; Lanna, Anna Cristina; Gomes, Maria Regina Araújo; José, Inês Chamel; Piovesan, Newton Deniz; Rezende, Sebastião Tavares de; Moreira, Maurilio AlvesThe involvement of lipoxygenase isozymes in several physiological processes of plants has been described but their role is not well understood and more biochemical studies are needed to elucidate the role of the "Lipoxygenase Pathway" in plant physiology. Thus, the biochemical and kinetic characterization of a lipoxygenases "pool" from soybean leaves was carried out. Two genotypes were used: IAC-100 (a normal variety having lipoxygenases in the seeds) and IAC-100 TN (genetically modified genotype, which is devoid of lipoxygenases in the seeds). The plants were submitted to the application of fatty acids (lipoxygenase substrates) on leaves. The results of the biochemical and kinetic studies of lipoxygenase isozymes from leaves of the two genotypes analysed showed that genetic removal of lipoxygenase from seeds did not affect the response of the plant to the treatment, since both genotypes showed similar results.Item Qualidade fisiologica de sementes de linhagens de soja sem lipoxigenases(Revista Ceres, 2002-07) Moreira, Maurilio Alves; Queiro, Telma Fallieri Nascimento; Sediyama, Carlos Sigueyuki; Rocha, Valterley SoaresPara avaliar possíveis alterações na qualidade fisiológica de sementes de soja, pela retirada das isoenzimas lipoxigenases (LOX l, 2 e 3), foram feitas avaliações em linhagens, com ausência das mesmas, submetidas a retardamento de colheita no campo. Foram utilizadas sementes dos cultivares Cristalina, Doko e [AC-12 com ou sem LOX, colhidas em quatro épocas: no estádio R8 e com 15, 30 e 45 dias de retardamento no campo. Avaliou-se a qualidade fisiológica pelo teste de germinação e de envelhecimento acelerado. Foi realizado também o teste de sanidade de sementes. Os genótipos analisados, sendo materiais distintos, apresentaram comportamento diferenciado. A porcentagem de germinação das linhagens sem LOX foi inferior à dos cultivares com LOX, excetuando-se linhagem Cristalina sem LOX, que foi superior. Tanto cultivares com LOX quanto linhagens sem LOX apresentaram perda de vigor com o retardamento de colheita, ressaltando-se que as linhagens sem LOX mostraram-se menos vigorosas. Houve maior incidência de fungos nas linhagens sem LOX. Os cultivares Cristalina, Doko com LOX ou sem elas e IAC-12 apresentaram grande ataque de fungos, e que, possivelmente, foi responsável por perdas no se:: poder germinativo e no vigor das suas sementes.Item Characterization and biotechnological application of an acid α-galactosidase from Tachigali multijuga Benth. seeds(Phytochemistry, 2008-10-02) Fialho, Lílian da Silva; Guimarães, Valéria Monteze; Callegari, Carina Marin; Reis, Angélica Pataro; Barbosa, Daianny Silveira; Borges, Eduardo Euclydes de Lima; Moreira, Maurilio Alves; Rezende, Sebastião Tavares deTachigali multijuga Benth. seeds were found to contain protein (364 mg g−1 dwt), lipids (24 mg g−1 dwt), ash (35 mg g−1 dwt), and carbohydrates (577 mg g−1 dwt). Sucrose, raffinose, and stachyose concentrations were 8.3, 3.0, and 11.6 mg g−1 dwt, respectively. α-Galactosidase activity increased during seed germination and reached a maximum level at 108 h after seed imbibition. The α-galactosidase purified from germinating seeds had an Mr of 38,000 and maximal activity at pH 5.0–5.5 and 50 °C. The enzyme was stable at 35 °C and 40 °C, but lost 79% of its activity after 30 min at 50 °C. The activation energy (Ea) values for p-nitrophenyl-α-d-galactopyranoside (pNPGal) and raffinose were 13.86 and 4.75 kcal mol−1, respectively. The Km values for pNPGal, melibiose, raffinose, and stachyose were 0.45, 5.37, 39.62 and 48.80 mM, respectively. The enzyme was sensitive to inhibition by HgCl2, SDS, AgNO3, CuSO4, and melibiose. d-Galactose was a competitive inhibitor (Ki = 2.74 mM). In addition to its ability to hydrolyze raffinose and stachyose, the enzyme also hydrolyzed galactomannan.Item Biochemical composition and indigestible oligosaccharides in Phaseolus vulgaris L. seeds(Plant Foods for Human Nutrition, 2006-06-20) Fialho, Lílian da Silva; Guimarães, Valéria Monteze; Barros, Everaldo Gonçalves de; Moreira, Maurilio Alves; Dias, Luiz Antônio dos Santos; Oliveira, Maria Goreti de Almeida; José, Inês Chamel; Rezende, Sebastião Tavares deCommon beans have a high nutritional value, but contain galactooligosaccharides (GO), which cause flatulence and intestinal discomfort in humans. The biochemical composition of ten bean cultivars was determined to select those of high protein and low GO contents. The cultivars varied in carbohydrate (47.02–60.17%), GO (3.12 – 5.71%), protein (22.17–33.50%), lipid (1.13–1.81%), moisture (11.42–12.93%) and ash contents (4.08–5.61%). ‘Mexico 222’ presented the highest α-galactosidase activity. Protein and GO contents were positively correlated. ‘Perry Marrow’ combined high protein and low GO concentrations, indicating it can be used in improvement programs aiming at high-quality cultivars for human consumption.