Hydrogen Sulfide in the Oxidative Stress Response of Plants: Crosstalk with Reactive Oxygen Species.

Growing evidence suggests that exposure of plants to unfavorable environments leads to the accumulation of hydrogen sulfide (H 2 S) and reactive oxygen species (ROS). H 2 S interacts with the ROS-mediated oxidative stress response network at multiple levels. Therefore, it is essential to elucidate the mechanisms by which H 2 S and ROS interact. The molecular mechanism of action by H 2 S relies on the post-translational modification of the cysteine sulfur group (-SH), known as persulfidation. H 2 S cannot react directly with -SH, but it can react with oxidized cysteine residues, and this oxidation process is induced by H 2 O 2 . Evidently, ROS is involved in the signaling pathway of H 2 S and plays a significant role. In this review, we summarize the role of H 2 S-mediated post-translational modification mechanisms in oxidative stress responses. Moreover, the mechanism of interaction between H 2 S and ROS in the regulation of redox reactions is focused upon, and the positive cooperative role of H 2 S and ROS is elucidated. Subsequently, based on the existing evidence and clues, we propose some potential problems and new clues to be explored, which are crucial for the development of the crosstalk mechanism of H 2 S and ROS in plants.