Melatonin Interplay with Phytohormones and Signaling Molecules Under Waterlogging Stress

Abstract

Waterlogging is a pivotal abiotic stressor that causes a severe threat to global crop production. Waterlogging stress negatively impacts plants, which induces oxidative damage while raising heavy metal contents and energy crisis, which leads to hindering metabolic processes and stunted plant growth. Melatonin is a low molecular weight indoleamine promising growth hormone that participates in multiple plant physiological and cellular activities. Melatonin acts as a strong free-radical scavenger and oxidizing agent as well to optimize redox homeostasis in plants by directly scavenging reactive oxygen species and reactive nitrogen species. The protective function of melatonin is to serve as a strong antioxidant within the plant cells. This chapter offers an extensive discussion about how melatonin boosts plant tolerance to waterlogging stress, enlightening the melatonin biosynthesis process, antioxidant functions, and its interaction with phytohormones and genes associated with hypoxic and low-oxygen conditions during waterlogging stress. This chapter also extends our present understanding of how melatonin-driven mechanisms increase plant tolerance to waterlogging stress.