Phytohormones as key regulators of plant resilience under salinity and extreme temperatures.

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conclusionPhytohormonal integration, rather than isolated hormone action, coordinates salinity and temperature-stress resilience through shared signaling hubs, cross-tolerance, and translational crop-improvement strategies. Salinity and temperature extremes, as abiotic stresses, affect over 20% of global arable land, reducing crop yields by up to 50% under severe conditions and greatly threatening food security. Phytohormones, which include abscisic acid, auxins, cytokinins, gibberellins, salicylic acid, jasmonates, and ethylene, are small signaling molecules that play central roles in mediating plant adaptation and resilience under such stresses. This review critically examines the mechanisms by which phytohormones regulate plant responses to salinity and temperature stress. Specifically, physiological adjustments, molecular signaling pathways, and cross-talk interactions are discussed. The phytohormone-mediated modulation of osmotic balance and ion homeostasis, reactive oxygen species scavenging, stress-responsive gene expression, and hormonal priming underpins plant tolerance, often improving survival rates by 20-40% under experimental stress. Furthermore, integrative signaling mechanisms that contribute to cross-tolerance are discussed, along with practical applications, such as exogenous hormone treatment, breeding strategies, and genetic engineering, aimed at developing climate-resilient crops. To guide future studies, emerging research directions, such as multi-omics approaches, CRISPR-based manipulation, and computational modeling, are highlighted. This review provides a comprehensive framework for leveraging phytohormonal regulation to enhance plant resilience under salinity and extreme temperatures.