Free Radicals Mediated Redox Signaling in Plant Stress Tolerance

Abstract

Abiotic and biotic stresses negatively affect plant cellular and biological processes, limiting their growth and productivity. Plants respond to these environmental cues and biotrophic attackers by activating intricate metabolic-molecular signaling networks precisely and coordinately. One of the initial signaling networks activated is involved in the generation of reactive oxygen species (ROS), reactive nitrogen species (RNS), and reactive sulfur species (RSS). Recent research has exemplified that ROS below the threshold level can stimulate plant survival by modulating redox homeostasis and regulating various genes of the stress defense pathway. In contrast, RNS regulates the stress tolerance potential of crop plants by modulating post-translation modification processes, such as S-nitrosation and tyrosine nitration, improving the stability of protein and DNA and activating the expression of downstream stress-responsive genes. RSS has recently emerged as a new warrior in combating plant stress-induced oxidative damage by modulating various physiological and stress-related processes. Several recent findings have corroborated the existence of intertwined signaling of ROS/RNS/RSS, playing a substantial role in crop stress management. However, the molecular mechanisms underlying their remarkable effect are still unknown. This review comprehensively describes recent ROS/RNS/RSS biology advancements and how they can modulate cell signaling and gene regulation for abiotic stress management in crop plants. Further, the review summarizes the latest information on how these ROS/RNS/RSS signaling interacts with other plant growth regulators and modulates essential plant functions, particularly photosynthesis, cell growth, and apoptosis.

Salicylic acid promotes phenolic acid biosynthesis for the production of phenol acid‐rich barley sprouts

“…However, the presence of too many ROS can alter the overall redox balance and lead to oxidative damage to biological macromolecules, such as nucleic acids, proteins, and lipids. 39 The accumulation of MDAone of the most significant byproducts of membrane lipid peroxidationcan exacerbate membrane damage. 40 The results of this study demonstrated that SA treatment considerably raised MDA content (P < 0.05), as well as H 2 O 2 and O 2 − fluorescence intensity, in comparison to the control (Figs.…”

“…Signal transduction, gene expression control, immunological response, and the mediation of numerous physiological processes in cells and organisms are all regulated by ROS. However, the presence of too many ROS can alter the overall redox balance and lead to oxidative damage to biological macromolecules, such as nucleic acids, proteins, and lipids 39 . The accumulation of MDA – one of the most significant byproducts of membrane lipid peroxidation – can exacerbate membrane damage 40 .…”