Hydrogen sulfide mechanism of action in plants; from interaction with regulatory molecules to persulfidation of proteins.

Hydrogen sulfide (HS), previously known as a toxic gas, is currently considered one of the most important gaseous transmitters in plants. This novel signaling molecule has been determined to play notable roles in plant growth, development, and maturation. In addition, pharmacological and genetic evidence indicated that this regulatory molecule effectively ameliorates various plant stress conditions. HS is involved in these processes by changing gene expression, enzyme activities, and metabolite concentrations. During its regulatory function, HS interacts with other signaling pathways such as hydrogen peroxide (HO), nitric oxide (NO), Ca, carbon monoxide (CO), phosphatidic acid (PA), phytohormones, etc. The HS mechanism of action may depend on the persulfidation post-translational modification (PTM), which attacks the cysteine (Cys) residues on the target proteins and changes their structure and activities. This review summarized HS biosynthesis pathways, its role in sulfide state, and its donors in plant biology. We also discuss recent progress in the research on the interactions of HS with other signaling molecules, as well as the role of persulfidation in modulating various plant reactions.