ABSTRACT
Most calcium activity is related to its capacity for coordination by which it provides stable but reversible intermolecular linkages especially in the cell walls and the plasma membrane. These Ca-mediated linkages respond to local changes in environmental conditions and are part of the control mechanism of growth and developmental processes. Calcium is a nontoxic mineral nutrient, even in high concentrations, and is very effective in detoxifying high concentrations of other mineral elements in plants.
There are two distinct areas in the cell wall with high Ca2+ concentrations, the middle lamella and the extension surface of the plasma membrane. In both sites, Ca2+ has essential structural functions, namely, the regulation of the membrane permeability and related processes and the strengthening of the cell walls.
