**3.4 Calcium signaling**

Calcium plays a role in a variety of abiotic stress symptoms, with varied degrees of directivity. Many of the functions in plants are governed by changes in intracellular calcium levels. Calcium is a harmful ion whose concentration in eukaryotic cells is controlled. Calcium ions travel through specific calcium ion channels, the cell membrane, or organelles into the cytosol after activation. Calcium ions have therefore been progressively increased to provide a number of final preparations for calcium-dependent proteins such as calmodulin, CDPCs and calmodulin-dependent phosphatases. Local calcium increases may also occur in specific organelles, such as chloroplasts, and can easily govern specific actions in organelles [67]. The expanded accurate determination of calcium as a result of abiotic stress, their association with downstream end progressions, and the use of calcium ion homeostasis inhibitors, however, highlight its importance.
