Carbonic Anhydrase Activity as an Indicator of Zinc Deficiency in Citrus Leaves

Abstract

Carbonic anhydrase is suggested as an indicator for diagnosing Zn deficiency when symptoms of Fe, Mn and Zn deficiency occur together. The enzyme was assayed in citrus leaves grown in a greenhouse in nutrient solutions deficient in various micronutrients. Consistent very low enzyme activity—about 25 % of that of the control—was found in the Zn-deficient leaves. Mn, Mo and Cudeficiencies in some cases reduced the activity slightly, whereas Fe deficiency increased it.