Ca²⁺ Signaling in Plant Cell Response and Adaptation to Low Temperature, Drought and Salt Stresses

The Ca²⁺ messenger plays important roles in plant growth and development, as well as in plant response and adaptation to the environment. In this review, we analyze the regulation mechanism of Ca²⁺ in plant adaptation to low temperature, drought and salt stress, including (1) Ca²⁺ subcellular localization and distribution, homeostasis in intracellular Ca²⁺ at a lower level acting as the basis of Ca²⁺ signal occurrence; (2) Ca²⁺ signal molecular superiority and its signaling pathway; (3) Cold acclimation and gene expression induced by Ca²⁺ signaling; (4) Physiological dormancy in over-wintering woody plants regulated by lasting high level of intracellular Ca²⁺; (5) Regulation of Ca²⁺ in drought and salt stresses; (6) Ca²⁺ signal in the regulation of stomatal closure/opening movement; (7) Roles of Ca²⁺ in the regulation of cell-wall thickening and strengthening under environmental stress.