INCREASED CARBONIC-ANHYDRASE ACTIVITY IN LEAVES OF SODIUM-DEFICIENT C4 PLANTS

The activity of carbonic anhydrase was determined in sodium-deficient and sodium-sufficient plants of Kochia childsii and Amaranthus tricolor. The enzyme extracted from leaves of sodium-deficient plants was found to be twice as active as that from leaves of control plants when expressed on a fresh weight or protein basis and three times as active on a chlorophyll basis. It was concluded that carbonic anhydrase activity was unlikely to limit the rate of photosynthesis in sodium-deficient C4 plants.