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Allantoinase catalyzes the hydrolysis of allantoin to allantoic acid, a reaction important in both biogenesis and degradation of ureides. Ureide production in cotyledons of germinating soybean (Glycine max L.) seeds has not been studied extensively but may be important in mobilizing nitrogen
Allantoinase (allantoin amidohydrolase, EC 3.5.2.5) catalyzes the conversion of allantoin to allantoic acid in the final step of ureide biogenesis. We have purified allantoinase more than 4000-fold by immunoaffinity chromatography from root nodules and cotyledons of soybean (Glycine max [L] Merr.).
During the period examined from 12 to 63 days after planting, the ureides, allantoin and allantoic acid, were the predominant nitrogenous solutes in the xylem exudate of soybeans (Glycine max [L.]) growing solely on symbiotically fixed nitrogen, accounting for approximately 60% and greater than 95%
Soybean (Glycine max L. [Merr]) plants export nitrogen from the nodules as ureides during symbiotic biological nitrogen fixation. Ureides also play a role as nitrogen storage compounds in the seeds and are broken down in germinating seedlings. In this work we identified four soybean genes encoding
Soybean (Glycine max) and pea (Pisum sativum) differ in the transport of fixed nitrogen from nodules to shoots. The dominant nitrogen transport compounds for soybean are ureides, while amides dominate in pea. A possible enzymic basis for this difference was examined.The level of enzymes involved in
Allantoate amidohydrolases (AAHs) hydrolize the ureide allantoate to ureidoglycolate, CO(2), and two molecules of ammonium. Allantoate degradation is required to recycle purine-ring nitrogen in all plants. Tropical legumes additionally transport fixed nitrogen via allantoin and allantoate into the
The ureides, allantoin and allantoic acid, are the major nitrogenous substances transported within the xylem of N(2)-fixing soybeans (Glycine max L. Merr. cv Amsoy 71). The ureides accumulated in the cotyledons, roots and shoots of soybean seedlings inoculated with Rhizobium or grown in the presence
The distribution of organelles and associated enzymes between cells containing bacteroids and uninfected cells from nodules of Glycine max L. Merr. cv Amsoy 71 was investigated by separation of protoplasts on a sucrose step-gradient. Infected protoplasts were much larger, irregular in shape, and
The appearance of enzymes involved in the formation of ureides, allantoin, and allantoic acid, from inosine 5'-monophosphate was analyzed in developing root nodules of soybean (Glycine max). Concomitant with development of effective nodules, a substantial increase in specific activities of the
The effect of nitrate on N(2) fixation and the assimilation of fixed N(2) in legume nodules was investigated by supplying nitrate to well established soybean (Glycine max L. Merr. cv Bragg)-Rhizobium japonicum (strain 3I1b110) symbioses. Three different techniques, acetylene reduction, (15)N(2)
The intracellular location of enzymes involved in the synthesis of the ureides, allantoin and allantoic acid, was investigated in nodules of Glycine max L. Merr. Cellular organelles were separated on isopycnic sucrose density gradients. Xanthine dehydrogenase activity (270 nanomoles per min per gram
Several ureides are intermediates of purine base catabolism, releasing nitrogen from the purine nucleotides for reassimilation into amino acids. In some legumes like soybean (Glycine max), ureides are used for nodule-to-shoot translocation of fixed nitrogen. Four enzymes of Arabidopsis (Arabidopsis