Effect of Potassium, Magnesium, and Calcium Deficiencies on Carbohydrate Pools and Metabolism in Citrus Leaves
Carbohydrate content and related enzyme activities were determined in leaves of rough-lemon (Citrus volkameriana Ten. & Pasq) plants grown under K, Mg, and Ca deficiencies. Starch content was lower and soluble sugar significantly higher in K-deficient than in control leaves. Magnesium- and Ca-deficient leaves, on the other hand, accumulated large amounts of starch. Electron micrographs also showed a reduction in the number and size of starch grains in chloroplasts of K-deficient leaves, while those of Mg- and Ca-deficient leaves were filled with large starch grains.