IRON-DEPENDENT UREIDES AND ALLANTIONASE SYNTHESIS IN PIGEON PEA

The effect of iron (Fe) on ureide metabolism was examined in 45-day-ol d pigeon pea (Cajanus cajan L.) (ureide plant) and alfalfa (Medicago s ativa) (amide plant). Plants were either inoculated with Rhizobium or fertilized with ammonium nitrate (NH4NO3). The ureides, allantoin and allantoate, and allanotinase activity were increased in pigeon pea wit h Fe supplementation. Specific effect of Fe on ureide metabolism of pi geon pea was indicated by the lack of same effect in alfalfa under sim ilar conditions. Nitrogenase activity was elevated with increasing con centrations of Fe in pigeon pea (ureide) as well as alfalfa (amide) sy mbiosis. Nitrogen (N2) fixation, ureides, and allantoinase activity we re reduced at 10 ppm and above concentration of Fe.