Drought Stress Tolerance in Vegetables: The Functional Role of Structural Features, Key Gene Pathways, and Exogenous Hormones

Abstract

The deleterious effects of drought stress have led to a significant decline in vegetable production, ultimately affecting food security. After sensing drought stress signals, vegetables prompt multifaceted response measures, eventually leading to changes in internal cell structure and external morphology. Among them, it is important to highlight that the changes, including changes in physiological metabolism, signal transduction, key genes, and hormone regulation, significantly influence drought stress tolerance in vegetables. This article elaborates on vegetable stress tolerance, focusing on structural adaptations, key genes, drought stress signaling transduction pathways, osmotic adjustments, and antioxidants. At the same time, the mechanisms of exogenous hormones such as abscisic acid (ABA), jasmonic acid (JA), salicylic acid (SA), and ethylene (ET) toward improving the adaptive drought tolerance of vegetables were also reviewed. These insights can enhance the understanding of vegetable drought tolerance, supporting vegetable tolerance enhancement by cultivation technology improvements under changing climatic conditions, which provides theoretical support and technical reference for innovative vegetable stress tolerance breeding and food security.

Physiological, Biochemical, and Molecular Response in Siete Caldos Chili Pepper Plants (Capsicum frutescens) Exposed to Water Deficit

“…Molla et al [57] highlight that genotypes with more extensive and voluminous root systems have more drought resistance than sensitive genotypes. Furthermore, vegetable roots play a crucial role under conditions of water deficit, enhancing water absorption from the lower soil layers, which contributes to their survival through elongation and thinning, and an increase in the extension of root hairs [58]. Meanwhile, Naikwade [6] mentions that drought avoidance also involves reversible physiological changes, such as decreased light absorption achieved by reducing leaf area through leaf curl and compact leaf architecture, for more efficient nutrient transport.…”

“…The decrease in MSI indicates considerable damage in the cell membrane, which may be related to the increase in lipid peroxidation generated by the increase in reactive oxygen species (ROS) due to oxidative stress, especially in chloroplast membranes, which was observed in chlorotic leaves and is more evident at 14 days, which coincides with the maximum decrease in MSI [32]. Abbas et al [58] point out that electrolyte leakage is a marker of drought tolerance capacity in horticultural plants. This is because tolerant genotypes maintain the integrity of their cell membranes, limiting electrolyte leakage in contrast to susceptible genotypes.…”

Effects of Jasmonic Acid on Stress Response and Quality Formation in Vegetable Crops and Their Underlying Molecular Mechanisms

“…JA has been shown to improve plant performance and regulate the stomatal status in plants under drought conditions. In the absence of water, the JAZ protein degrades and activates related transcription factors (such as MYC2), which then stimulate the upregulation of stress tolerance genes [ 90 ]. Research shows that the cassava SPL9 negatively regulates crop drought resistance, and rMeSPL9-SRDX overexpression lines showed increased proline and anthocyanin contents as well as endogenous JA and soluble sugar accumulations [ 91 ].…”

The Cooperation Regulation of Antioxidative System and Hormone Contents on Physiological Responses of Wedelia trilobata and Wedelia chinensis under Simulated Drought Environment

“…Plants employ various strategies to adapt to fluctuating water stress conditions, including osmotic regulation, antioxidant enzyme activities, and a range of endogenous hormones [ 15 ]. These intrinsic plant hormones play essential roles in regulating physiological functions, enabling plants to effectively cope with drought stress [ 16 ].…”