Drought Stress and its Tolerance Mechanism in Wheat

Abstract

Plants encounter diverse forms of stress in response to fluctuations in their surrounding environment. Drought is a very detrimental environmental stressor that negatively impacts crop Plants. The phenomenon of drought stress in Plants is characterized by its intricate nature, arising from many environmental factors, including limited soil water availability, elevated soil salinity levels, and increased ambient temperature. The latter is referred to as physiological drought. The wheat plant exhibits high sensitivity to dry conditions, particularly during the flowering and grain-filling stages. The phenomenon led to a significant decline in the growth and production of wheat crops. Water stress during crucial growth stages, including tillering, grain filling, and flowering, has been identified as a significant factor leading to substantial reductions in crop output. Drought stress in wheat induces morphological, physiological, biochemical, and molecular alterations. Plants employ three fundamental survival strategies, stress avoidance, escape, and tolerance, in response to drought-induced stress. The cultivation of drought-tolerant cultivars and the implementation of agronomic practices play a crucial role in the development of novel water-use strategies for effective drought management. Drought tolerance is a multifaceted characteristic governed by multiple genes, with their expressions modulated by diverse environmental factors. Therefore, the challenge of breeding for this particular trait is considerable, necessitating the utilization of novel molecular techniques such as molecular markers, quantitative trait loci [QTL] mapping procedures, and gene expression patterns to generate genotypes that exhibit tolerance to drought conditions. Wheat possesses multiple genes that contribute to drought stress tolerance by encoding various enzymes and proteins, such as late embryogenesis abundant [LEA], abscisic acid-responsive [RAB], rubisco, helicase, proline, glutathione-S-transferase [GST], and carbohydrates, which are involved in mitigating the effects of drought stress. This review paper has focused on examining the impact of water limitation on several aspects of wheat, including its morphology, physiology, biochemistry, and molecular responses. Additionally, it explores the potential losses incurred by wheat due to drought-induced stress.