Unlocking Nature’s Stress Reliever: The Role of Melatonin in Enhancing the Resilience of Fruit Crops Against Abiotic Stress

Melatonin (MT), discovered as N‑acetyl-5-methoxytryptamine in 1958, exhibits significant potential as a regulator of plant growth, development and responses to environmental stressors. Its diverse levels across organs and species make it an intriguing subject for functional studies. This review explores the potential of MT, whether administered endogenously or exogenously, in mitigating various environmental stressors such as cold, metal toxicity, drought, salinity, chilling injuries, temperature fluctuations etc. A pivotal aspect of MT action involves its direct inhibition of reactive oxygen species (ROS) and reactive nitrogen species (RNS), pivotal players in oxidative stress. Mechanisms like enhanced antioxidant enzyme activity, bolstered non-enzymatic antioxidant systems, and activation of enzymes repairing oxidized proteins contribute to MT’s ability to confer resistance against abiotic stresses. Furthermore, by inducing the expression of genes related to antioxidant enzymes during stress, MT acts as a key regulator in orchestrating plant defense responses against environmental challenges. These collective actions underscore the role of MT in enhancing plant resilience to such challenges. The interaction of MT with various phytohormones in drought stress regulation prompts exploration of similar mechanisms to address diverse stressors in horticultural crops. MT’s collaborative synergy with fungicides presents a promising strategy for reducing reliance on harmful chemicals in fruit crop cultivation, thereby minimizing the environmental impact and enhancing crop management practices. However, this review also underscores the need for further research to explore how MT protects fruit crops from environmental challenges, potentially leading to environmentally friendly agricultural practices and safer food production.