Melatonin's chromatic magic: Examining its role in orchestrating pigment biosynthesis in horticultural crops

Abstract

Melatonin, a remarkably versatile molecule found in plants, exerts a broad spectrum of physiological effects, and holds notable significance across a variety of plant species. Its synthesis occurs via the shikimate pathway and necessitates the involvement of three enzymes for successful transformation. Remarkably, certain plants can biosynthesize substantial quantities of melatonin, which can be stored in specialized organs. The melatonin level in plants exhibit significant variation, and they can surge in response to environmental stressors, thereby bolstering stress adaptation. By virtue of its exceptional antioxidant properties, melatonin serves as an asset for plant revitalization, fortifying tolerance against cold exposure, and optimizing the intricate processes of photosynthesis. Moreover, melatonin serves as a pivotal regulator of hormone levels and stress-responsive genes, actively contributing to the intricate network of plant defense mechanisms. Its protective role in mitigating chilling stress proves particularly advantageous for the long-term storage of germplasm. Notably, the application of exogenous melatonin demonstrates promise in enhancing metabolic processes, preserving fruit quality, and orchestrating the synthesis of anthocyanins which give boosts to aesthetic value addition. The comprehensive understanding of melatonin's profound impact on plant processes holds tremendous potential for fostering sustainable agricultural practices and advancing our knowledge of plant biology.