About this Research Topic
Melatonin (N-acetyl-5-methoxytryptamine) is a tryptophan-derived indole amine molecule present in animals, plants and microbes. It was first identified in animals in 1958 where it mediates the regulation of circadian and seasonal rhythms. Melatonin and its derivatives protect animal cells by scavenging many types of ROS/RNS and up-regulate the expression of antioxidative enzymes. It also can act as an anti-inflammatory and immunomodulator, with the potential to reduce the severity of disease-associated symptoms.
Discovered in plants a quarter of a century ago, phytomelatonin has been reported from many mono- and dicotyledonous species. As for animals, phytomelatonin is a potent hydroxy radical scavenger. Research investigating the effects of exogenous melatonin application and gene expression of melatonin-related genes indicate that the endogenous levels of phytomelatonin can modulate many aspects of plant growth and can have a protective role by reducing the negative effects of biotic and abiotic stresses.
Phytomelatonin biosynthesis de novo involves four main enzymatic steps. While several alternate biosynthetic pathways have been elucidated, the biosynthesis and function of phytomelatonin derivatives are less well understood. Phytomelatonin derivatives can be generated by enzymatic conversion or by direct interaction with ROS. The physiological significance of melatonin-derived metabolites in increasing stress tolerance is just emerging, with the function of many still unknown.
This Research Topic will focus on phytomelatonin metabolism and physiological roles in planta, and will be a follow up on 'Melatonin in plants' . Here, we seek submissions that address how melatonin alone or in association with other melatonin-derived compounds can modulate plant physiology and what other role(s) they may have. We are considering manuscripts from all plant types, including crops and trees, investigating the distribution, biosynthesis de novo, regulation, and transport of melatonin and melatonin-derived compounds, as well as their physiological effects in planta. All types of articles including original research, mini review, review, methods, perspectives and opinions are welcomed.
Keywords: Phytomelatonin, melatonin, plant physiology, stress
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