Insights into Drought Stress Signaling in Plants and the Molecular Genetic Basis of Cotton Drought Tolerance

Abstract

Drought stress restricts plant growth and development by altering metabolic activity and biological functions. However, plants have evolved several cellular and molecular mechanisms to overcome drought stress. Drought tolerance is a multiplex trait involving the activation of signaling mechanisms and differentially expressed molecular responses. Broadly, drought tolerance comprises two steps: stress sensing/signaling and activation of various parallel stress responses (including physiological, molecular, and biochemical mechanisms) in plants. At the cellular level, drought induces oxidative stress by overproduction of reactive oxygen species (ROS), ultimately causing the cell membrane to rupture and stimulating various stress signaling pathways (ROS, mitogen-activated-protein-kinase, Ca2+, and hormone-mediated signaling). Drought-induced transcription factors activation and abscisic acid concentration co-ordinate the stress signaling and responses in cotton. The key responses against drought stress, are root development, stomatal closure, photosynthesis, hormone production, and ROS scavenging. The genetic basis, quantitative trait loci and genes of cotton drought tolerance are presented as examples of genetic resources in plants. Sustainable genetic improvements could be achieved through functional genomic approaches and genome modification techniques such as the CRISPR/Cas9 system aid the characterization of genes, sorted out from stress-related candidate single nucleotide polymorphisms, quantitative trait loci, and genes. Exploration of the genetic basis for superior candidate genes linked to stress physiology can be facilitated by integrated functional genomic approaches. We propose a third-generation sequencing approach coupled with genome-wide studies and functional genomic tools, including a comparative sequenced data (transcriptomics, proteomics, and epigenomic) analysis, which offer a platform to identify and characterize novel genes. This will provide information for better understanding the complex stress cellular biology of plants.

Light acts as a stressor and influences abiotic and biotic stress responses in plants

“…Drought activates specific signalling pathways resulting in physiological and developmental adaptations to optimize water use (Fahad et al, 2017; Nakashima, Yamaguchi‐Shinozaki, & Shinozaki, 2014). The plant hormone abscisic acid (ABA) is essential for the response to drought stress, but both ABA‐dependent and ‐independent signalling cascades are involved in the transcriptional regulation of target genes to increase the plant's resistance to drought stress (Joshi et al, 2016; Kim et al, 2012; Mahmood et al, 2019).…”

Incredible Role of Osmotic Adjustment in Grain Yield Sustainability under Water Scarcity Conditions in Wheat (Triticum aestivum L.)

“…Prior to plant yield, drought stress affects physiological and morphological traits in plants throughout their life cycle. Plant stability under water deficit conditions is largely dependent on reduced water losses under harsh environments [ 3 , 4 , 5 ]. Progress in drought tolerance breeding is not satisfactory due to the complexity of measuring drought tolerance, which limits the significant yield improvement.…”

Transcriptome Profiling of Haloxylon persicum (Bunge ex Boiss and Buhse) an Endangered Plant Species under PEG-Induced Drought Stress

“…Under stress condition, the phosphorylation of target genes are regulated by MAPK, which controls the activity of different structural proteins and various transcription factors which are involved in abiotic stress tolerance. Along with transcription factors (TFs), MAPK signal cascade also plays an important role in ABA-dependent and ABA-independent abiotic stress responses in plants [15]. Overall, various metabolic pathways and signaling molecules are involved in plants defense against abiotic stress.…”