Plant hormones and neurotransmitter interactions mediate antioxidant defenses under induced oxidative stress in plants

Due to global climate change, abiotic stresses are affecting plant growth,\r\nproductivity, and the quality of cultivated crops. Stressful conditions disrupt\r\nphysiological activities and suppress defensive mechanisms, resulting in\r\nstress-sensitive plants. Consequently, plants implement various endogenous\r\nstrategies, including plant hormone biosynthesis (e.g., abscisic acid, jasmonic\r\nacid, salicylic acid, brassinosteroids, indole-3-acetic acid, cytokinins, ethylene,\r\ngibberellic acid, and strigolactones) to withstand stress conditions. Combined\r\nor single abiotic stress disrupts the normal transportation of solutes, causes\r\nelectron leakage, and triggers reactive oxygen species (ROS) production,\r\ncreating oxidative stress in plants. Several enzymatic and non-enzymatic\r\ndefense systems marshal a plant’s antioxidant defenses. While stress\r\nresponses and the protective role of the antioxidant defense system have\r\nbeen well-documented in recent investigations, the interrelationships among\r\nplant hormones, plant neurotransmitters (NTs, such as serotonin, melatonin,\r\ndopamine, acetylcholine, and g-aminobutyric acid), and antioxidant defenses\r\nare not well explained. Thus, this review discusses recent advances in\r\nplant hormones, transgenic and metabolic developments, and the potential interaction of plant hormones with NTs in plant stress response and\r\ntolerance mechanisms. Furthermore, we discuss current challenges and\r\nfuture directions (transgenic breeding and genome editing) for metabolic\r\nimprovement in plants using modern molecular tools. The interaction of\r\nplant hormones and NTs involved in regulating antioxidant defense systems,\r\nmolecular hormone networks, and abiotic-induced oxidative stress tolerance\r\nin plants are also discussed.