An Overview of the Impact of Melatonin on Tomato's Abiotic Stress Responses

Tomatoes, as one of the main vegetables in the world, are facing increasingly greater cultivation challenges due to environmental changes. The challenges include abiotic stresses such as high temperatures, drought, and salinity, which significantly impact tomato growth. Melatonin, a hormone recognized for its function in the human sleep cycle, has surfaced as a potential remedy for improving plant resilience. This article explores the effects of melatonin on tomatoes, particularly under abiotic stress. A comprehensive literature search using Scopus, ScienceDirect, Web of Science, PubMed, and ProQuest ensures the synthesis of relevant scientific literature. This review reports that the melatonin content in tomatoes varies among plant organs and is influenced by environmental factors. The application of exogenous melatonin has been proven beneficial in stress conditions, enhancing antioxidant activities, photosynthesis, and stress resistance. The function of melatonin in gene regulation, antioxidants, and signaling pathways contributes to stress adaptation. The biosynthesis of melatonin in plants includes the enzymatic conversion of tryptophan. Although much is already known, future research is essential to comprehend the function of several melatonin features in sustaining plant equilibrium under environmental stresses.