The Interplay between Hydrogen Sulfide and Phytohormone Signaling Pathways under Challenging Environments.

Hydrogen sulfide (H 2 S) serves as an important gaseous signaling molecule that is involved in intra- and intercellular signal transduction in plant-environment interactions. In plants, H 2 S is formed in sulfate/cysteine reduction pathways. The activation of endogenous H 2 S and its exogenous application has been found to be highly effective in ameliorating a wide variety of stress conditions in plants. The H 2 S interferes with the cellular redox regulatory network and prevents the degradation of proteins from oxidative stress via post-translational modifications (PTMs). H 2 S-mediated persulfidation allows the rapid response of proteins in signaling networks to environmental stimuli. In addition, regulatory crosstalk of H 2 S with other gaseous signals and plant growth regulators enable the activation of multiple signaling cascades that drive cellular adaptation. In this review, we summarize and discuss the current understanding of the molecular mechanisms of H 2 S-induced cellular adjustments and the interactions between H 2 S and various signaling pathways in plants, emphasizing the recent progress in our understanding of the effects of H 2 S on the PTMs of proteins. We also discuss future directions that would advance our understanding of H 2 S interactions to ultimately mitigate the impacts of environmental stresses in the plants.