Phytohormones and plant growth regulators as sustainable modulators of salinity stress tolerance in major crops: Mechanistic insights and environmental perspectives

ABSTRACT Salinity stress is a predominant abiotic constraint that severely limits the yield of many crops worldwide. Its increasing prevalence is primarily attributed to saline irrigation, low precipitation, native rock weathering, excessive surface evaporation, and overuse of fertilizers. Salinity induces osmotic imbalance, ionic toxicity, and oxidative damage, thereby impairing crop performance and leading to remarkable yield losses. According to the Global Map of Salt-Affected Soils, over 1.2 billion hectares of land across 118 countries are affected by salinity, comprising 424 million hectares of surface soil and 833 million hectares of subsoil. To safeguard global food security (SDG-2) and strengthen adaptive capacity to climate change (SDG-13), it is imperious to explore strategies that enhance crop resilience to salinity stress. Phytohormones such as auxins, cytokinins, gibberellins, abscisic acid, and ethylene, along with plant growth regulators i.e., brassinosteroids, polyamines, strigolactones, play pivotal roles in regulating plant responses to salt stress at physiological, biochemical, and molecular levels. This review delivers a comprehensive overview of recent advances in understanding the various roles of these signalling molecules in modulating salinity tolerance. Furthermore, it highlights their mechanisms of action in mitigating stress-induced damages and maintaining cellular homeostasis. Harnessing phytohormones and plant growth regulators represents a sustainable and eco-friendly approach for improving crop performance in salt-affected soils, offering new opportunities for developing stress-resilient crop varieties and ensuring future food security.