Mechanisms of Ion Uptake by Leaves with Special Reference to Isolated Leaf Cells and Their Components

摘要

The micro-nutrient zinc and possibly all other micronutrients are absorbed by plant tissues (intact roots, isolated leaf cells, leaf disks, excised roots, stem callus tissue) primarily by a passive process. Absorption as compared with phosphate uptake, is not temperature or light dependent, or subject to metabolic inhibitors, and is strongly dependent on the external zinc concentration and pH. The data suggest a passive mechanism, involving possibly a physical or physio-chemical binding of the micro-nutrient ions to the cell wall and free space components and a passive diffusion into the interior of the cell.