Melatonin-mediated development and abiotic stress tolerance in plants

Abstract

Melatonin is a multifunctional molecule that has been widely discovered in most plants. An increasing number of studies have shown that melatonin plays essential roles in plant growth and stress tolerance. It has been extensively applied to alleviate the harmful effects of abiotic stresses. In view of its role in regulating aspects of plant growth and development, we ponder and summarize the scientific discoveries about seed germination, root development, flowering, fruit maturation, and senescence. Under abiotic and biotic stresses, melatonin brings together many pathways to increase access to treatments for the symptoms of plants and to counteract the negative effects. It has the capacity to tackle regulation of the redox, plant hormone networks, and endogenous melatonin. Furthermore, the expression levels of several genes and the contents of diverse secondary metabolites, such as polyphenols, terpenoids, and alkaloids, were significantly altered. In this review, we intend to examine the actions of melatonin in plants from a broader perspective, explore the range of its physiological functions, and analyze the relationship between melatonin and other metabolites and metabolic pathways.

Morphological and Physiological Mechanisms of Melatonin on Delaying Drought-Induced Leaf Senescence in Cotton

“…In contrast, IAA, GA 3 , and CTK play active roles in delaying leaf senescence. MT can alleviate the inhibition of senescence by regulating IAA, GA 3 , and CTK biosynthesis [ 53 ]. The findings of this study were consistent with previous studies affirming that MT delays leaf senescence under DS by up-regulating IAA, GA 3 , and iPA biosynthesis-related genes ( GhYUC5 , GhGA3ox2 , and GhIPT2 ) and increasing the endogenous IAA, GA 3 , and iPA content ( Figure 7 ).…”

Unraveling the regulatory role of MYC2 on ASMT gene expression in wheat: Implications for melatonin biosynthesis and drought tolerance

“…Accumulation of ROS due to drought stress causes damage to membranes and organelles and extensive cellular activity changes (Ilyas et al, 2021; Shamloo‐Dashtpagerdi et al, 2019; Zhang et al, 2022). Melatonin acts as a potent antioxidant and a plant antioxidant system (AOS) inducer, scavenging ROS and mitigating oxidative damage caused by drought stress (Back, 2021; Zhang et al, 2023). Elevated melatonin contents and increased activities of antioxidant enzymes, including SOD, POD, and CAT, in response to JA, DR, and JA + DR indicate an enhanced antioxidant defense system in wheat, which mitigate oxidative damage to cellular components such as chloroplast and mitochondria.…”

“…It has also been suggested that melatonin regulates ABA biosynthesis genes, resulting in better stomatal function under stress conditions (Li et al, 2015). Moreover, melatonin's positive effect on plants' photosynthesis under different stress conditions has been reported (Altaf et al, 2022;Rehaman et al, 2021;Zhang et al, 2023). Melatonin regulates the carbon fixation pathway.…”

“…Melatonin is a versatile molecule with multiple functions in plants, including antioxidant activity, regulation of growth and development, and modulation of stress responses (Arnao & Hernández‐Ruiz, 2019; Sun et al, 2021). It has been reported to be crucial in enhancing plant tolerance to various stresses (Altaf et al, 2022; Shamloo‐Dashtpagerdi et al, 2022b; Wang et al, 2018; Zhang et al, 2023). However, the mechanisms regulating internal melatonin levels in plants are still poorly elucidated.…”

“…Drought response and tolerance involve a complex interplay of genetic, biochemical, and physiological processes with numerous essential genes and pathways, including phytohormones (Ahmad et al, 2018; Manna et al, 2021; Salvi et al, 2021). Plant melatonin has recently garnered attention as an emergent phytohormone critical in stress responses, including drought tolerance (Tiwari et al, 2021; Zhang et al, 2023). Melatonin acts as a signaling molecule, affecting gene expression through interactions with specific melatonin receptors and modulating the activity of transcription factors involved in stress‐responsive pathways.…”