ROS and NO Regulation by Melatonin Under Abiotic Stress in Plants.

Miriam Pardo-Hernández,Rosa M Rivero,Maria López-Delacalle

doi:10.3390/antiox9111078

Miriam Pardo-Hernández, Rosa M Rivero + Show 1 more

Open Access

https://doi.org/10.3390/antiox9111078

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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.

Highlights

Abiotic or biotic stresses, such as drought, heat, cold, salinity, pathogen attack and high light, either individual or combined, negatively affect plant growth, reproduction and survival, which will limit agricultural crop productivity and yield [1]
Other results revealed that the rhizospheric application of MET remarkably enhanced the drought tolerance of alfalfa (Medicago sativa L.) plants through nitro-oxidative homeostasis via the regulation of reactive oxygen (SOD, glutathione reductase (GR), CAT, ascorbate peroxidase (APX)) and nitrogen species (NR, NADH dehydrogenase) metabolic enzymes at the enzymatic and/or transcript level
Relatively few research studies have been focused on the genes and core pathways that are regulated by MET

Summary

Introduction

Abiotic or biotic stresses, such as drought, heat, cold, salinity, pathogen attack and high light, either individual or combined, negatively affect plant growth, reproduction and survival, which will limit agricultural crop productivity and yield [1]. Perhaps the most important function described for MET in living organisms is related to its role in non-receptor-mediated activities, such as scavenging of ROS and reactive nitrogen species (RNS) and improving the cell’s antioxidant capacity, preventing cells, tissues, and organisms from suffering oxidative stress [15]. In this sense, MET modulates and quickly upregulates the activity of different antioxidant enzymes and stress tolerance-related genes, and activates downstream signaling transduction pathways when the plant is exposed to abiotic or biotic stress or the perception of MET [29,30]. MET can interact with unknown receptors in the activation of H2O2/NO signaling pathways, and further improve plant stress tolerance by regulating a variety of antioxidant enzymes, alleviating photosynthesis inhibition and modulating the activity of various transcription factors [35]

ROS-Plant Mediated Stress Response and Its Relationship with MET

NO-Plant Mediated Stress Response and Its Relationship with MET

Findings

Conclusions and Future Perpectives