Leaves of bean plants (Phaseolus vulgaris L.) deficient in potassium and the proper control of two cultivars were analysed in relation to ornithine transcarbamylase (E.C. 2.1.3.3) and glutamic-oxaloacetic transaminase (E.C. 2.6.1.1) activities. Leaves of bean plants grown under potassium deficiency showed higher activities of both enzymes. These dada suggest that the accumulation of citrulline and arginine in potassium deficient plants was due to the higher activity of ornithine transcarbamylase, probably as a mechanism to reduce ammonium toxicity.
ornithine transcarbamylase; glutamic-oxaloacetic transaminase; bean; Phaseolus vulgaris