ROS and autophagy in plant stress responses: adaptive partners in survival

Reactive oxygen species (ROS) and autophagy play crucial roles in adaptation and survival under abiotic stress by maintaining cellular homeostasis through a tightly coordinated network. While basal levels of ROS function as essential signaling molecules, excessive accumulation leads to oxidative damage. Autophagy mitigates this by selectively degrading oxidized macromolecules and damaged organelles through specialized pathways, such as chlorophagy, mitophagy, and pexophagy, and recycling essential nutrients to sustain cellular metabolism under stress. This review addresses an important gap in the field by critically evaluating conflicting evidence and examining how ROS-autophagy responses differ between model plants and crop species, distinctions that have implications for agricultural applications. We discuss the reciprocal regulation between ROS and autophagy across multiple stress scenarios, including drought, salinity, heat, cold, and nutrient deprivation. ROS regulate autophagy through both direct molecular mechanisms and indirect signaling pathways, while autophagy helps limit ROS accumulation through clearance of compromised organelles. By comparing species-specific responses and identifying current knowledge gaps, this review provides guidance for translating fundamental research into crop improvement strategies.