Pyruvate Kinase Activity of Wheat Plants Grown under Potassium Deficient Conditions

The activity of pyruvate kinase was determined in the first leaves of wheat plants grown under K(+)-deficient conditions. An enhancement of the enzyme activity compared with the normal plants was found to start from eighth day of growth, and about 4-fold increase in the enzyme activity was observed in 14-day wheat leaves. The addition of K(2)SO(4) to the nutrient solution given to the K(+)-deficient plants at tenth day resulted in the restoration of the enzyme activity to the normal level after 3 days. The levels of K(+) as well as carbohydrates and chlorophyll were found to return normal over the same period. These findings are discussed in relation to the metabolic pattern of plants at the early stages of K(+)-deficiency.