Physiological quality, content and activity of antioxidants in soybean seeds artificially aged.

ABSTRACT - The objective of this study was to evaluate physiological quality, content, and activity of antioxidants, in soybean seeds subjected to accelerated aging during different periods. Seeds of cultivars BRS 258, BRS 262 and BRS 268, subjected to accelerated aging during 12, 24, 36 and 48 hours and non-aged seeds were used. After each aging period, the seed were evaluated by tests of: germination; first count and tetrazolium. The total of phenolic compounds, total flavonoides, total of isoflavones, and activity for eliminating ABTS°+ radicals were quantified. There were differences among cultivars according to vigor and viability only after seeds were aged. Cultivars BRS 158 and BRS 268 have shown better seed physiological quality in each aging period; however, not presenting higher amounts of isoflavones and efficiency in removing free radicals. For all cultivars, the values for total of phenolic compounds, as well as total of flavonoids have shown quadratic positive behavior; the values for isoflavones remained constant and the vigor and viability showed contrary trend to activity of antioxidant agents. RESUMO: Qualidade fisiológica, conteúdo e atividade de antioxidantes presentes em sementes de soja envelhecidas artificialmente. O objetivo deste trabalho foi avaliar a qualidade fisiológica, o conteúdo e a atividade de agentes antioxidantes presentes em sementes de soja envelhecidas durante diferentes períodos. Foram utilizadas sementes das cultivares BRS 258, BRS 262 e BRS 268, envelhecidas durante 12, 24, 36 e 48 h e sementes não envelhecidas. Após cada período de envelhecimento, as sementes foram avaliadas pelo testes de: germinação; primeira contagem e tetrazólio. Foram quantificados: compostos fenólicos totais; flavonóides totais; total de isoflavonas e atividade eliminadora do radical ABTS°+. Houve diferença entre as cultivares em relação ao vigor e viabilidade somente quando foram envelhecidas. BRS 158 e BRS 268 apresentaram melhor qualidade fisiológica de sementes em cada período de envelhecimento, porém, não apresentaram maior quantidade de isoflavonas e eficiência no sequestro dos radicais livres. Para todas as cultivares, os valores de compostos fenólicos totais, assim como os flavonóides totais, apresentaram comportamento quadrático positivo; os valores das isoflavonas permaneceram constantes e o vigor e a viabilidade apresentaram tendência contrária à atividade dos agentes antioxidantes

Effects of a methanolic fraction of soybean seeds on the transcriptional activity of peroxisome proliferator-activated receptors (PPAR)

Since the anti-inflammatory, antidiabetic and hypolipidemic effects of soy isoflavones may be mediated by activation of peroxisome proliferator-activated receptors (PPAR), the present study investigated whether the methanolic fractions obtained from soybean seeds (E1) and soybean seed coats with hypocotyls (E2) could influence PPAR&#945;, PPAR&#947; and PPAR&#946;/&#948; transcriptional activity. The isoflavones from E1 and E2 were quantified by HPLC analysis. E1 and E2 were rich in isoflavones (daidzin, glycitin, genistin, malonyldaidzin, malonylglycitin, malonylgenistin, daidzein, glycitein, and genistein). Moreover, E1 and E2 showed no evidence of genetically modified material containing the gene CP4 EPSPS. To investigate PPAR transcriptional activity, human promonocytic U-937 cells were treated with E1 and E2 (200, 400, 800, and 1600 µg/mL), positive controls or vehicle. Data are reported as fold-activation of the luciferase reporter driven by the PPAR-responsive element. Dose-response analysis revealed that E1 and E2 induced the transcriptional activity of PPAR&#945; (P < 0.001), with activation comparable to that obtained with 0.1 mM bezafibrate (positive control) at 1600 µg/mL (4-fold) and 800 µg/mL (9-fold), respectively. In addition, dose-response analysis revealed that E1 and E2 activated PPAR&#946;/&#948; (P < 0.05), and the activation at 800 µg/mL (4- and 9-fold, respectively) was comparable to that of 0.1 mM bezafibrate (positive control). However, no effect on PPAR&#947; was observed. Activation of PPAR&#945; is consistent with the lipid-lowering activity of soy isoflavones in vivo, but further studies are needed to determine the physiological significance of PPAR&#946;/&#948; activation

Novos genótipos de triticum durum L.: rendimento, adaptabilidade e qualidade tecnológica New genotypes of triticum durum L.: grain yield, adaptability and technological quality

Compararam-se dezoito genótipos de Triticum durum L. e dois de Triticum aestivum L. em experimentos semeados em condições de irrigação por aspersão em diferentes regiões tritícolas paulistas, durante o período de 1995-97. Analisaram-se os seguintes parâmetros: rendimento de grãos, altura de plantas, ciclo da emergência à maturação, resistência às manchas foliares causadas por helmintosporiose, adaptabilidade, estabilidade, e qualidade tecnológica. O IAC 24 (T. aestivum) foi o mais produtivo, não diferindo dos genótipos de T. durum ALTAR/STN (12), MEMOS "S"/YAV79/3/SAPI"S"/TEAL"S"//HUI"S" (17), STN"S"/3/TEZ"S"/YAV79//HUI"S" (6), ALTAR/STN (11) e WIN"S"/SBA81A//STIL"S" (14) na comparação das médias para rendimento de grãos. Verificou-se que, em Ribeirão Preto, o rendimento médio de grãos foi de 5.332 kg/ha no período. Observaram-se valores semelhantes do coeficiente de determinação (R2) para a maioria dos genótipos estudados, exceto para IAC 24 e IAC 1001. Este e o Anahuac apresentaram-se instáveis quanto à produção de grãos nos ambientes desfavoráveis e estável nos favoráveis, ao contrário do IAC 24. As infecções do agente causal de mancha-foliar foram baixas, sendo as ocorrências mais generalizadas em Tatuí. Os melhores genótipos de T. durum em relação à qualidade tecnológica foram os tratamentos IAC 1003 (1), SCO"S"/3/BD1814//BD708/BD1543/4/ROK"S" (13), Altar 84 (15) e MEMOS"S"/YAV79/3/SAPI"S"/TEAL"S"//HUI"S" (17), enquadrando-se os demais genótipos na classificação de farinha (sêmola) médio-fraca, produzindo massa de má qualidade. Estimou-se que as variáveis: tempo de desenvolvimento, sedimentação, índice de tolerância à mistura, energia de deformação da massa, número de queda, tenacidade versus elasticidade (P/L) e estabilidade seriam, em ordem de importância, parâmetros a considerar na seleção de cada genótipo, conjuntamente com o rendimento de grãos e sua adaptabilidade.<br>Eighteen durum wheat and two bread wheat genotypes were evaluated for grain yield, plant height, cycle from emergence to maturity, resistance to leaf spots caused by Helminthosporium sp, adaptability, stability and technological quality, in experiments, under sprinkler irrigation, carried out at different regions of State of São Paulo, Brazil. The bread wheat IAC 24 presented the highest yield but not differing from the durum genotypes ALTAR/STN (12), MEMOS"S"/YAV79/3/SAPIS"S"/TEAL"S"//HUI"S" (17), STN"S"/3/TEZ"S"/YAV79//HUI"S" (6), ALTAR/STN (11) and WIN"S"SBA81A//STIL"S"(14). At Ribeirão Preto site the grain yield mean of the evaluated genotypes was 5,332 kg/ha, in the period. Coefficients of determination for all genotypes were similar with exception for IAC 24 and IAC 1001. The last one, a durum wheat, showed instable in relation to grain yield under not favorable environments, and stable under favorable environments. The bread wheat IAC 24 presented opposite behaviour. The infection of the causal agent of leaf spot was low, but at Tatuí site the occurrence of this disease was more generalized. The best durum wheat genotypes in relation to quality were IAC 1003 (1), SCO"S"/3/BD1814//BD708/BD1543/4/ROK"S"(13), ALTAR 84 (15) and MEMOS"S"/YAV79/3/SAPI"S"/TEAL"S"/HUI"S" (17). The other durum wheat genotypes presented medium to low flour strength producing bad quality dough. Dough development time, sedimentation test, index of mixture tolerance, energy for deformation of the dough, falling number, tenacity versus elasticity (P/L) and dough stability were in order of importance the parameters to be considered combined with grain yield and adaptability for the genotype selections