Metabolism and Translocation of Allantoin in Ureide-Producing Grain Legumes

Metabolism and translocation of allantoin in ureide-producing grain legumes.

Transfer of the nitrogen and carbon of allantoin to amino acids and protein of leaflets, stems and petioles, apices, peduncles, pods, and seeds of detached shoots of nodulated cowpea (Vigna unguiculata L. Walp. cv. Caloona) plants was demonstrated following supply of [2-(14)C], [1,3-(15)N]allantoin in the transpiration stream. Throughout vegetative and reproductive growth all plant organs showe...

Nitrogen Nutrition and Xylem Transport of Nitrogen in Ureide-producing Grain Legumes.

Xylem sap composition was examined in nodulated and nonnodulated cowpea (Vigna unguiculata [L.] Walp.) plants receiving a range of levels of NO(3) and in eight other ureide-forming legumes utilizing NO(3) or N(2) as sole source of nitrogen. A (15)N dilution technique determined the proportions of plant nitrogen derived from N(2) in the nodulated cowpeas fed NO(3). Xylem sap composition of NO(3)...

Update on ureide degradation in legumes.

Warm season N2-fixing legumes move fixed N from the nodules to the aerial portions of the plant primarily in the form of ureides, allantoin and allantoate, oxidation products of purines synthesized de novo in the nodule. Ureides are also products of purine turnover in senescing tissues, such as seedling cotyledons. A combination of biochemical and molecular approaches in both crop and model spe...

Kinetics of allantoin metabolism in sheep.

The kinetics of allantoin metabolism were studied in rumen-cannulated sheep by means of a single intravenous injection of [4,5-(14)C]allantoin. The decline in the specific radioactivity of allantoin in plasma following the injection of tracer was best described by a double exponential function, indicating that allantoin moves in and out of two or more kinetically distinct compartments. Sequeste...

The Grain Legumes Integrated Project