Crosstalk between Ca2+ and Other Regulators Assists Plants in Responding to Abiotic Stress

Plants have evolved many strategies for adaptation to extreme environments. Ca2+, acting as an important secondary messenger in plant cells, is a signaling molecule involved in plants' response and adaptation to external stress. In plant cells, almost all kinds of abiotic stresses are able to raise cytosolic Ca2+ levels, and the spatiotemporal distribution of this molecule in distant cells suggests that Ca2+ may be a universal signal regulating different kinds of abiotic stress. Ca2+ is used to sense and transduce various stress signals through its downstream calcium-binding proteins, thereby inducing a series of biochemical reactions to adapt to or resist various stresses. This review summarizes the roles and molecular mechanisms of cytosolic Ca2+ in response to abiotic stresses such as drought, high salinity, ultraviolet light, heavy metals, waterlogging, extreme temperature and wounding. Furthermore, we focused on the crosstalk between Ca2+ and other signaling molecules in plants suffering from extreme environmental stress.