Plant Water-Stress Response Mechanisms

Abstract

© 2014 Springer India. All rights reserved.Water, the central molecule of life, plays a profound role in a number of plant life processes ranging from photosynthesis to macromolecular interaction through hydrophobic bond. Due to imbalances in natural status of the different physiological, environmental conditions and during natural calamities, plants are exposed to either deficit of water (i.e. drought) or excess of water (i.e. flooding). Both of these conditions lead to water stress on plants which in turn results in disruption of agriculture and food supply in different parts of the world. In this chapter, a brief idea on the causes, indicators, responses and adaptation processes to the water stress in plants and the associated molecular mechanisms has been presented. In this chapter, the stresses related to water are expressed as drought. The cellular and molecular responses of plants to water stress have been studied intensively throughout the world. Understanding the mechanisms by which plants perceive water stress and transmit the subsequent signals to cellular machinery and modulate expression of genes and their products to activate adaptive responses is of fundamental importance to plant biology. Knowledge about water-stress signal transduction is therefore vital for continued development of rational breeding and transgenic strategies to improve stress tolerance in crops. Factors controlling water-stress conditions alter the normal equilibrium and lead to a series of morphological, physiological, biochemical and molecular changes in plants which adversely affect their growth and productivity. However, plants also have developed innate adaptations to water-stress conditions with an array of biochemical and physiological interventions that involve the function of many stress-associated genes. Water-stress-associated hormones like ABA are found to play a central role in orchestrating the molecular and physiological responses leading protective responses in plants. Overall, this chapter provides a systemic glimpse of integrated cellular and whole plant responses to water stress.