Salicylic acid (SA) enhances abiotic stress tolerance in plants by modulating biochemical, physiological, and molecular mechanisms. Abiotic stresses such as salinity, drought, metal toxicity, and UV-B radiation significantly impact plant growth and productivity. SA, a phytohormone, plays a crucial role in improving plant tolerance to these stresses by regulating key physiological processes, including photosynthesis, antioxidant defense, and stress-related gene expression. SA induces the synthesis of osmolytes like glycinebetaine (GB) and proline (Pro), which help maintain cellular osmotic balance and protect against oxidative stress. It also enhances the activity of antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT), and peroxidases, which mitigate the damage caused by reactive oxygen species (ROS). SA modulates the expression of defense-related genes, including those involved in pathogenesis-related (PR) proteins and heat shock proteins (HSPs), thereby strengthening plant resistance to abiotic stresses. Additionally, SA interacts with other phytohormones such as auxin, cytokinin, and abscisic acid (ABA), influencing stress responses through signaling cross-talks. SA also enhances the uptake and metabolism of essential minerals, improving plant growth under stressful conditions. Overall, SA improves plant tolerance to various abiotic stresses by activating defense mechanisms, regulating redox balance, and modulating gene expression, making it a valuable tool for sustainable agriculture.Salicylic acid (SA) enhances abiotic stress tolerance in plants by modulating biochemical, physiological, and molecular mechanisms. Abiotic stresses such as salinity, drought, metal toxicity, and UV-B radiation significantly impact plant growth and productivity. SA, a phytohormone, plays a crucial role in improving plant tolerance to these stresses by regulating key physiological processes, including photosynthesis, antioxidant defense, and stress-related gene expression. SA induces the synthesis of osmolytes like glycinebetaine (GB) and proline (Pro), which help maintain cellular osmotic balance and protect against oxidative stress. It also enhances the activity of antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT), and peroxidases, which mitigate the damage caused by reactive oxygen species (ROS). SA modulates the expression of defense-related genes, including those involved in pathogenesis-related (PR) proteins and heat shock proteins (HSPs), thereby strengthening plant resistance to abiotic stresses. Additionally, SA interacts with other phytohormones such as auxin, cytokinin, and abscisic acid (ABA), influencing stress responses through signaling cross-talks. SA also enhances the uptake and metabolism of essential minerals, improving plant growth under stressful conditions. Overall, SA improves plant tolerance to various abiotic stresses by activating defense mechanisms, regulating redox balance, and modulating gene expression, making it a valuable tool for sustainable agriculture.