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

Abstract

Due to global climate change, abiotic stresses are affecting plant growth, productivity, and the quality of cultivated crops. Stressful conditions disrupt physiological activities and suppress defensive mechanisms, resulting in stress-sensitive plants. Consequently, plants implement various endogenous strategies, including plant hormone biosynthesis (e.g., abscisic acid, jasmonic acid, salicylic acid, brassinosteroids, indole-3-acetic acid, cytokinins, ethylene, gibberellic acid, and strigolactones) to withstand stress conditions. Combined or single abiotic stress disrupts the normal transportation of solutes, causes electron leakage, and triggers reactive oxygen species (ROS) production, creating oxidative stress in plants. Several enzymatic and non-enzymatic defense systems marshal a plant’s antioxidant defenses. While stress responses and the protective role of the antioxidant defense system have been well-documented in recent investigations, the interrelationships among plant hormones, plant neurotransmitters (NTs, such as serotonin, melatonin, dopamine, acetylcholine, and γ-aminobutyric acid), and antioxidant defenses are not well explained. Thus, this review discusses recent advances in plant hormones, transgenic and metabolic developments, and the potential interaction of plant hormones with NTs in plant stress response and tolerance mechanisms. Furthermore, we discuss current challenges and future directions (transgenic breeding and genome editing) for metabolic improvement in plants using modern molecular tools. The interaction of plant hormones and NTs involved in regulating antioxidant defense systems, molecular hormone networks, and abiotic-induced oxidative stress tolerance in plants are also discussed.

Regulation of Na+/H+ exchangers, Na+/K+ transporters, and lignin biosynthesis genes, along with lignin accumulation, sodium extrusion, and antioxidant defense, confers salt tolerance in alfalfa

“…Plants frequently accumulate free proline and soluble sugar to alleviate osmotic stress, which is involved in maintaining membrane integrity with optimal water potential ( Quilambo, 2004 ). Sugar is also involved in the regulation of photosynthesis, stress-responsive genes, antioxidant system, and alleviation of abiotic stress ( Sami et al., 2016 ; Raza et al., 2022a ). However, the higher concentration of proline and soluble in this study provided more support to ZM for coping salt-induced osmotic stress than XJD.…”

Exogenous melatonin confers cold tolerance in rapeseed (Brassica napus L.) seedlings by improving antioxidants and genes expression

“…When plants are subjected to stress, a large number of osmotic adjustment substances are accumulated to maintain cell osmotic potential. 15 , 28 For instance, Li, Zeng 21 found that the soluble sugar, soluble protein, and proline contents were increased by MEL in rapeseed seedlings under drought conditions. 21 Melatonin significantly increased the content of soluble protein, sugar, and proline and the SOD and POD activity of wheat seedlings at low temperatures.…”

Physiological and transcriptomic analysis uncovers salinity stress mechanisms in a facultative crassulacean acid metabolism plant Dendrobium officinale

“…Phytohormones coordinate all aspects of plant growth and development, as well as stress responses ( Shan et al., 2012 ). Plant hormones interact with five key plant neurotransmitters, including serotonin, melatonin, dopamine, acetylcholine and γ-aminobutyric acid, and participate in many physiological processes such as photosynthesis, oxidative stress and osmotic regulation ( Raza et al., 2022b ). Two groups of phytohormones, auxins and cytokinins, have been clearly demonstrated as the main regulators of plant development ( Benjamins and Scheres, 2008 ; Werner and Schmülling, 2009 ; Schaller et al., 2015 ) and stress responses ( Hare et al., 1997 ; Blakeslee et al., 2019 ).…”