Role of Molecular Breeding Tools in Enhancing the Breeding of Drought-Resilient Cotton Genotypes: An Updated Review

Abstract

Drought stress is an inevitable factor that disturbs the production of plants by altering morphological, physiological, biochemical, and molecular functions. Breeding for drought tolerance requires a complete understanding of the molecular factors controlling stress-responsive pathways. The plant responds to drought stress by adopting four mechanisms: avoidance, escape, tolerance, and recovery. Traditional plant-breeding tools have been employed to increase tolerance in cotton, but the complexity of drought tolerance has limited the use of these breeding methods. The plant adopts several key strategies against drought stress, such as activating the signaling network and activating molecular factors. Cotton breeders have been engaged in elucidating the molecular mechanisms of drought tolerance in cotton using significant molecular tools such as quantitative trait loci (QTL) mapping, transcription factor (TFs) analysis, transcriptome analysis, genome-wide association studies (GWAS), genetic engineering, and CRISPR/Cas9. Breeders have studied the functional description of genes and the interacting pathways accountable for controlling drought tolerance in cotton. Hundreds of genes/QTL have been identified, and many have been cloned for drought tolerance in cotton; however, a complete understanding of these traits still needs more study. This review presents a detailed overview of molecular tools, their application for improving drought tolerance in cotton, and their prospects. This review will help future researchers to conduct further studies to develop drought-tolerant cotton genotypes that can thrive under conditions of water scarcity.

Harnessing nanobiotechnology for drought stress: transforming agriculture's future; what, why and how?

“…28 Numerous secondary implications associated with drought stress imposition on crops' overall productivity and growth have been highlighted. 7,8,29 Various plant species exhibit distinct strategies for coping with drought stress, including undergoing a facilitated life cycle prior to the beginning of the drought, possessing the capacity to hold on to higher levels of water content during drought conditions, 30 showing that varying root hydraulic conductivity boosts aquaporin expression to enhance water transport, and synthesizing dehydrin stress proteins. 31,32 Plants can accumulate osmoprotectants and osmolytes to protect their proteins and membranes against the damaging effects of drought-induced denaturation.…”