ROS and NO Regulation by Melatonin Under Abiotic Stress in Plants

Abstract

Abiotic stress in plants is an increasingly common problem in agriculture, and thus, studies on plant treatments with specific compounds that may help to mitigate these effects have increased in recent years. Melatonin (MET) application and its role in mitigating the negative effects of abiotic stress in plants have become important in the last few years. MET, a derivative of tryptophan, is an important plant-related response molecule involved in the growth, development, and reproduction of plants, and the induction of different stress factors. In addition, MET plays a protective role against different abiotic stresses such as salinity, high/low temperature, high light, waterlogging, nutrient deficiency and stress combination by regulating both the enzymatic and non-enzymatic antioxidant defense systems. Moreover, MET interacts with many signaling molecules, such as reactive oxygen species (ROS) and nitric oxide (NO), and participates in a wide variety of physiological reactions. It is well known that NO produces S-nitrosylation and NO2-Tyr of important antioxidant-related proteins, with this being an important mechanism for maintaining the antioxidant capacity of the AsA/GSH cycle under nitro-oxidative conditions, as extensively reviewed here under different abiotic stress conditions. Lastly, in this review, we show the coordinated actions between NO and MET as a long-range signaling molecule, regulating many responses in plants, including plant growth and abiotic stress tolerance. Despite all the knowledge acquired over the years, there is still more to know about how MET and NO act on the tolerance of plants to abiotic stresses.

Melatonin Improves Cotton Salt Tolerance by Regulating ROS Scavenging System and Ca2 + Signal Transduction

“…We found that salt treatment can induce an increase in the level of endogenous melatonin in cotton seedlings; exogenous application of melatonin can regulate antioxidant enzymes, redox-related genes, glutathione, etc. In order to remove ROS, melatonin can also induce the accumulation of some representative non-enzymatic antioxidants, such as AsA, phenolic compounds, flavonoids and carotenoids ( Pardo-Hernández et al, 2020 ); as a broad-spectrum antioxidant, interacts with ROS and directly eliminates it ( Lins et al, 2012 ); melatonin induced the expression of some hormones (Auxin, ABA, Ethylene, Brassinosteroid, Jasmonic acid) synthesis and signal transduction related genes, and coordinates other hormones in the cotton defense network; melatonin induced the expression of some transcription factors (AP2/ERF-ERF, C2H2, bHLH, WRKY, etc.) to resist salt stress; melatonin induced the expression of genes related to the phosphatidylinositol signaling system and activates some signaling molecules (IP3, DAG, IP6, Ca 2+ ), Phospholipase C (PLC) hydrolyses PtdInsP2 to generate InsP3 and DAG, which can be converted into PA as a signal molecule and PA as a membrane localization signal.…”

Roles of Endogenous Melatonin in Resistance to Botrytis cinerea Infection in an Arabidopsis Model

“…It can respond to various biotic ( Mandal et al, 2018 ; Zhao et al, 2021 ) and abiotic ( Chen et al, 2017 ; Yao et al, 2020 ) stresses to resist the influence of environmental changes during plant growth and development. The immune response of melatonin in plants requires the participation of many signaling molecules, such as reactive oxygen species (ROS; Pardo-Hernández et al, 2020 ) and Nitric Oxide (NO; Zhu et al, 2019 ), to transmit both intracellular and intercellular signals. In the field of biotic stress, melatonin is involved in plant resistance to numerous fungus ( Moustafa-Farag and Almoneafy, 2019 ).…”

Melatonin in Plant Defense against Abiotic Stress

“…Research has shown that coordination between melatonin and NO as a signaling molecule performs many actions in plants such as growth and abiotic stress tolerance [186]. Metabolites that are enhanced are carbohydrates such as fructose, galactose, glucose, sucrose, and proline that are important components of osmotic adaptation in abiotic stress response [96].…”

“…Research has shown that coordination between melatonin and NO as a signaling molecule performs many actions in plants such as growth and abiotic stress tolerance [186].…”