ROS-induced oxidative post-translational modifications in plants: another switch for ROS signaling

Reactive oxygen species (ROS) are pivotal signaling molecules that regulate plant growth and development and stress responses. Among these, hydrogen peroxide (H₂O₂), with its relatively long half-life and high stability, plays a dominant role in redox signal transduction. The primary biological function of H₂O₂ is achieved through post-translational modifications of proteins, with cysteine residues being the main targets of its oxidative modifications. Exposure of redox-sensitive cysteine thiols (-SH) to H₂O₂ results in reversible (sulfenylation, -SOH; disulfide bond, -S-S; and S-glutathionylation, -SSG) or irreversible (sulfinylation, -SO₂H; and sulfonylation, -SO₃H) oxidative modifications. These ROS-mediated oxidative post-translational modifications (Oxi-PTMs) are increasingly becoming part of the ROS signaling pathway, and may even be regarded as molecular switches. Therefore, this review delves into ROS-induced Oxi-PTMs and elucidates their significance as critical regulatory switches in ROS signal transduction. Initially, the main types of ROS-induced Oxi-PTMs are summarized, and how these modifications specifically alter the structure, activity and function of proteins to regulate intracellular signaling pathways. Subsequently, the role of S-glutathionylation in ROS signaling in activating or inhibiting key signaling proteins is discussed in detail. Additionally, it compiles key transcription factors directly regulated by Oxi-PTMs and their functions. Ultimately, it proposes potential future research directions and novel insights based on the current state of the field.