Effect of Low Nitrate Applied at Preflowering Stage on Nodular Pep Carboxylase Activity in Soybean (Glycine Max. L. Merr)

The effect of low dose of nitrogen (5mM KNO₃ applied thrice with irrigation water at preflowering stage) on PEP carboxylase in soybean was investagited under pot culture condition. The nitrate application increased NR activity, photosynthesis and nitrogenase activity in nodules but the activity of PEP case which fixes CO₂ in nodules was not affected. Lack of responsiveness of nodular PEP case suggests its limited role in soybean which is a ureide transporting legume.