Recebido para publicação em 7/8/2007 Aceito para publicação em 8/7/2009 (002743) 1 Departamento de Nutrição, Universidade Estadual do Centro-Oeste – UNICENTRO, Rua Camargo Varela de Sá, 03, Bairro Vila Carli, CEP 85040-080, Guarapuava PR, E-mail: [email protected] 2 Ciências e Letras de Paranaguá, Faculdade Estadual de Filosofia, Universidade Estadual do Paraná 3 Departamento de Tecnologia de...

Levels of nitrate reductase activity (EC 1.9.6.1.) as high as 11 mumoles nitrite produced/hour gram fresh weight were found in barley (Hordeum vulgare cv. Compana) roots grown under low oxygen conditions. Roots of plants given identical treatment under sterile conditions did not develop the high levels of nitrate reductase activity. The results suggest that the buildup of particulate, reduced v...

To investigate the growth response of various crop species to mycorrhizal inoculation, arbuscular mycorrhizal fungi were applied to Glycine max, Vigna angularis, Senna tora, Hordeum vulgare var. hexastichon. Zea mays, Sorghum bicolor, Allium tuberosum, Solanum melongena, and Capsicum annuum. The biomass of the inoculated crops was measured every two weeks for the 12-week growth period. By measu...

Turnover of ribulose 1,5-diphosphate carboxylase in barley leaves (Hordeum vulgare L.) was followed over time in light and dark. The enzyme was degraded in prolonged darkness and was resynthesized after the plants were returned to light. Labeling with (14)C showed that simultaneous synthesis and degradation (turnover) did not occur in light. In contrast, the remaining soluble protein was turned...

The electrophoretic mobilities of the cytoplasmic ribosomal proteins of several species of plants were compared using two-dimensional electrophoresis. The total number of proteins as well as the number of acidic and basic proteins in individual species varied markedly. Of the species examined, Triticum aestivum had the highest number of basic cytoplasmic ribosomal proteins and Hordeum vulgare h...

The Pyricularia genus includes several pathogenic fungi species that are associated with blast disease in more than 50 Poaceae plants (Ou 1985). Among these species, Pyricularia oryzae is the most important pathogen, due to its global distribution on plants from the Poaceae family. The blast disease caused by P. oryzae is responsible for severe losses in crops of high economic importance such a...

The subcellular compartmentation of nucleoside diphosphate kinase (EC 2.7.4.6) and the uridine nucleotides has been studied in leaves. Membrane filtration of barley (Hordeum vulgare L.) leaf mesophyll protoplasts and differential centrifugation of spinach (Spinacia oleracea L.) leaf extracts showed that about half the nucleoside diphosphate kinase is present in the cytosol. The activity is adeq...

Inorganic orthophosphate (25 millimolar in assay media; Pi) was found to increase in vitro activity of NADH-nitrate reductase (NR) isolated from 2-row barley (Hordeum vulgare L.) leaves with a saturating concentration of nitrate (2 millimolar) but to decrease it with low nitrate levels (<0.1 millimolar). The response to nitrate concentrations was Pi specific. The Lineweaver-Burk plot showed tha...

The Ca, Mg, K, and P content of dry barley (Hordeum vulgare) grains and seedlings was investigated using energy dispersive x-ray analysis and neutron activation analysis. Energy dispersive x-ray analysis of protein bodies in aleurone cells showed that these bodies contained very little Ca in relation to P, Mg, and K. Neutron activation analysis also showed that the endosperm contained very litt...