Regulation of Calcium Uptake and Translocation in Plants

Calcium (Ca) is an essential plant nutrient and a second messenger in cell signal transduction. Recently, most of the research on Ca in plants has been focused on the role of Ca at the cellular level. But the uptake and transport are also very important for Ca to accomplish its function at the whole plant level. The uptake of Ca involves Ca entering one cell then exiting from this cell and entering another cell, which is influenced by metabolism and temperature. The overexpression of Ca2+/H+ transporter can increase Ca levels of transgenic plants significantly. Ca2+ enter the symplast from apoplastic pathways through Ca2+ channels. Ca2+-ATPase can drive Ca2+ flux from symplast to apoplast. The uptake and transport of Ca are also regulated by phytohormones, rootstock and genotype. There is a tight linkage of Ca and auxin countercurrent fluxes.