Hydrogen Sulfide Signaling in Plants

Significance: Hydrogen sulfide (H2S) is a multitasking potent regulator that facilitates plant growth, development, and responses to environmental stimuli. Recent Advances: The important beneficial effects of H2S 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 H2S signaling. An increasing number of studies, including large-scale proteomic analyses and functional characterizations, have revealed that H2S-mediated persulfidations directly regulate protein functions, altering downstream signaling in plants. To date, the importance of H2S-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 H2S-regulatory mechanism. Critical Issues: The molecular mechanisms of the H2S sensing and transduction in plants remain elusive. The correlations of H2S-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 H2S 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 H2S signaling in plants. Antioxid. Redox Signal. 39, 40–58.