Influence of Drought Stress on Morphological, Physiological and Biochemical Attributes of Plants: A Review

Drought poses the most significant environmental constrain that limits the growth and yield efficiency of vegetables around the world. The major challenges lies is to identify potential genetic resources and technology development that improve quality and productivity of vegetable crops under declining land, reducing natural resources and increasing environmental stresses. Varied responses of different crop species/genotypes to water-deficit condition have been studied for a long time, and several morphological, physiological and biochemical characters have been suggested to be responsible for drought tolerance. Understanding the morphological, physiological and biochemical responses to drought is essential for a holistic perception of plant resistance mechanisms to water-limited conditions and also to design screening techniques for drought tolerance that may be employed in crop breeding. Drought stress lead to the overproduction of reactive oxygen species (ROS) in plants which inactivate enzymes and damage important cellular components. The effects of the action of free radicals on membranes include the induction of lipid peroxidation and fatty acid de-esterification. Plants possess very efficient enzymatic and non-enzymatic antioxidant defense systems which work in concert to control the cascades of uncontrolled oxidation and protect plant cells from oxidative damage by scavenging of ROS. In this review the important morphological, physiological and biochemical traits that are influenced by drought stress, and may be important indices for identification/screening of drought tolerant genotypes in vegetable crops has been described.