Melatonin-mediated physiological and molecular responses to abiotic stress in horticultural crops

Horticultural crops suffer massive production losses due to abiotic stress, which is a key limiting factor worldwide. The ability of these crops to withstand such stress has been linked to melatonin, a biomolecule with significant roles in both physiological and molecular defense responses. Melatonin is pivotal in enhancing the resilience of horticultural crops to abiotic stress, making it a critical component in their survival strategies. The application of exogenous melatonin improves abiotic stress tolerance by preserving membrane integrity, maintaining redox equilibrium, scavenging reactive oxygen species effectively, activating antioxidant defense mechanisms, and elevating gene expression related to stress responses. Furthermore, the integrated management of melatonin with other phytohormones demonstrates its potential relevance in addressing various stresses across a wide range of horticultural crops. Therefore, it is crucial to elucidate the physiological and molecular processes involving melatonin in abiotic stress in these crops. Here, we discuss current studies on the use of melatonin in horticultural crops in response to abiotic stresses, and explores future research directions and potential applications to enhance the productivity and abiotic stress tolerance of horticultural crops.