ABSTRACT
Agriculture crops are frequently exposed to various abiotic stresses that are influence growth, development and productivity. Drought stress constitutes a major issue affecting plant productivity nowadays. The plants exhibited various morphological, anatomical, physiological, molecular and biochemical responses to water shortage conditions. The production of reactive oxygen species (ROS) is the noteworthy response of different plants to drought stress, which oxidatively affects the cellular biomolecules causing oxidative damage. The plants develop an arsenal of antioxidants to reduce the noxious impact of the oxidative burst of ROS under drought stress and other environmental stress conditions. The plants predominately metabolize various ROS via antioxidant enzymes such as catalase, guiacol peroxidase, ascorbate peroxidase, superoxide dismutase, glutathione reductase and glutathione peroxidase. The plants developed non-enzymatic antioxidants like ascorbate, dehydroascorbate, oxidized and reduced glutathione, carotenoids, phenolic compounds, flavonoids, anthocyanins, tocopherols, etc., to work synergically to trap different ROS produced under the drought stress. This chapter will consider the impact of drought on plants; provides exclusively detailed information on the role of enzymatic antioxidants in mitigating damage impacts of drought stress; and discusses the contribution of the stress-responsive genes and proteins in conferring drought tolerance.
