Calcium Signaling in Plants Under Drought

Environmental stresses are among the most important threats for food security since it adversely affects agricultural productivity. Among them, drought stress and water scarcity stand as major problems, especially in developing countries. Thus, understanding molecular mechanisms involving drought stress response is of essential importance for coping with its detrimental effects. Calcium is an essential macro-element, taking part in the regulation of many aspects of plant growth and development along with playing the role of ubiquitous secondary messenger, thus taking part in the generation of adaptive responses toward various developmental and environmental stimuli. Therefore, understanding the calcium signaling and calcium-dependent processes is crucial for improving plant productivity under environmental stresses. Formation of calcium signature through subsequent oscillations is at the onset of calcium signaling which further activates calcium-binding proteins which are acting as signal decoders, makes it possible to perceive the nature of stimuli. Further, protein kinases and transcription factors are activated in a stimuli-specific manner to create a stress-specific response. Understanding of calcium signaling processes and modulations is a promising step for unraveling the molecular mechanism of drought stress tolerance and engineering stress-tolerant crops. In this chapter, calcium-signaling components involving in drought stress signal perception and transition through calcium-signaling pathway and final formation of stress response have been discussed in detail.