Study and Synthesis of Melatonin as a Strong Antioxidant in Plants

Document Type : Original Research


1 Department of Life Sciences and Systems Biology, Plant Physiology Unit, University of Turin.

2 Department of Biological, Chemical and Pharmaceutical Sciences and Technologies (STEBICEF), University of Palermo


A plant's chloroplasts and mitochondria synthesize melatonin (N-acetyl-5 methoxytryptamine), which is an indole compound derived from tryptophan. All plant species contain melatonin in varying amounts depending on the organ or tissue. Due to its multiple functions in plants, this molecule is considered a growth regulator. The significant effects of melatonin on auxin, gibberellin, cytokinin, and abscisic acid hormones are among its important functions. The antioxidant properties of melatonin are similar to those of auxin in plants. Plant physiological responses to melatonin include seed germination and embryo development, photosynthesis (pigment content, photorespiration, stomatal conductance, and water consumption), seed and fruit production, osmotic regulation, and metabolism. Plants respond to melatonin by increasing their resistance to abiotic stresses such as drought, cold, heat, salinity, chemicals, herbicides, and ultraviolet rays. Melatonin's antioxidant properties are responsible for a variety of physiological responses. This review summarizes the chemistry and metabolism of melatonin. Additionally, plant and animal biosynthetic pathways have been studied. In addition, dietary supplementation and the use of bio stimulant formulations have been widely discussed as methods of administering exogenous melatonin to animals or plants.

Graphical Abstract

Study and Synthesis of Melatonin as a Strong Antioxidant in Plants