Hydrogen Sulfide Signaling in Plants

Significance: Hydrogen sulfide (H 2 S) is a multitasking potent regulator that facilitates plant growth, development, and responses to environmental stimuli. Recent Advances: The important beneficial effects of H 2 S in various aspects of plant physiology aroused the interest of this chemical for agriculture. Protein cysteine persulfidation has been recognized as the main reduction–oxidation (redox) regulatory mechanism of H 2 S signaling. An increasing number of studies, including large-scale proteomic analyses and functional characterizations, have revealed that H 2 S-mediated persulfidations directly regulate protein functions, altering downstream signaling in plants. To date, the importance of H 2 S-mediated persulfidation in several abscisic acid signaling-controlling key proteins has been assessed as well as their role in stomatal movements, largely contributing to the understanding of the plant H 2 S-regulatory mechanism. Critical Issues: The molecular mechanisms of the H 2 S sensing and transduction in plants remain elusive. The correlations of H 2 S-mediated persulfidation with other oxidative post-translational modifications of cysteines are still to be explored. Future Directions: Implementation of advanced detection approaches for the spatiotemporal monitoring of H 2 S levels in cells and the current proteomic profiling strategies for the identification and quantification of the cysteine site-specific persulfidation will provide insight into the H 2 S signaling in plants. Antioxid. Redox Signal. 39, 40–58.