Role of plant hormones in stress tolerance: A molecular perspective

Abstract

Plants frequently face environmental challenges such as drought, salinity, cold, heat, and heavy metal toxicity, which threaten their survival and productivity. In response, they have evolved intricate hormonal signaling networks to perceive, transduce, and respond to stress signals. Plant hormones—also known as phytohormones—such as abscisic acid (ABA), salicylic acid (SA), jasmonic acid (JA), ethylene (ET), gibberellins (GAs), cytokinins (CKs), auxins, brassinosteroids (BRs), and strigolactones (SLs) play crucial roles in modulating physiological and molecular responses under both abiotic and biotic stress conditions. This review explores the molecular interplay of plant hormones in enhancing stress tolerance. Special emphasis is laid on hormonal crosstalk, receptor-mediated signal transduction, transcriptional regulation, and downstream effectors. The review also highlights emerging tools such as CRISPR/Cas genome editing, omics technologies, and hormone analog development in understanding and engineering stress resilience. A detailed discussion of how hormonal homeostasis and dynamic signaling modulate ROS scavenging, stomatal movement, gene expression, and cellular adaptation mechanisms is provided. Recent advancements up to 2024 are reviewed to provide an up-to-date understanding of the complex hormonal networks involved in stress adaptation. Visual data in the form of comprehensive graphs and tables support this analysis. Finally, the article suggests potential avenues for future research and biotechnological applications in crop improvement strategies to meet the growing food demands under changing climatic conditions.