Reactive oxygen species (ROS) are central players in plant abiotic stress responses, functioning as both toxic byproducts and vital signaling molecules. Under normal physiological conditions, ROS participate in the regulation of plant growth and development. However, under stress conditions, ROS metabolism exhibits remarkable stress-specificity, leading to either adaptive signaling or oxidative damage. A comparative understanding of these distinct patterns is critical for advancing stress tolerance engineering. This review systematically elaborates on the mechanisms of ROS production under various abiotic stresses, their dual roles in signaling and oxidative damage, and the corresponding multilayer antioxidant adaptations in plants. We place particular emphasis on comparing the characteristic ROS signatures and regulatory networks triggered by drought, salinity, extreme temperatures, heavy metals, ultraviolet radiation and ozone. Furthermore, we summarize cutting-edge technologies for in vivo ROS detection that are revolutionizing the spatiotemporal understanding of ROS dynamics, these advanced tools enable real-time, subcellular resolution of ROS production, scavenging, and signaling processes, thereby propelling the mechanistic dissection of plant redox homeostasis under stress. Ultimately, we highlight how plants achieve acclimation by precisely orchestrating the “double-edged sword” nature of ROS through an integrated regulatory network. This synthesis not only consolidates the mechanistic understanding but also offers a strategic perspective for designing crops with tailored ROS regulatory capacities to enhance resilience in a changing climate.
Liu et al. (2026) studied this question.