Calcium alleviates stress in plants: insight into regulatory mechanisms

Plants as sessile organisms are constantly exposed to different stressors incidence: biotic and / or abiotic factors. Consequently, the viability of plants depends on their ability to perceive the changes that occur in their natural environment (either beneficial or harmful) and to appropriately respond physiologically, biochemically, and in terms of their development, to overcome and to counter the possible destructive effects. Plasma membrane, as the main selective barrier between the plant cell and the environment have different receptor proteins in its structure, to sense various external stimuli and transduce them to downstream intra- and intercellular signalling networks. An universal signal molecule is calcium and the calcium-sensing is of fundamental importance for extracellular calcium signalling and calcium homeostasis. Calcium is an important second messenger in signal transduction pathways, mediating various defence responses to the action under environmental stresses and in the regulation of many developmental processes in plants, being one of the most studied second messengers both in plant and animal fields. This brief review summarizes some results of recent research on the involvement of calcium in plant responses to stress factors action, addressing in particular scientific and practical importance of such knowledge, in order to improve plant tolerance to stress factors.