Redox-based protein persulfidation in guard cell ABA signaling.

Hydrogen sulfide (HS) is a versatile signaling molecule that regulates multiple physiological processes in plants, including growth and development, immunity, and stress response as well. Signaling triggered by HS is proposed to occur via persulfidation, an oxidative post-translational modification (PTM) of cysteine residues (-SH) to persulfides (-SSH). Notwithstanding the growing body of information for the plant persulfidation proteome, the gap between the molecular mechanism of HS and physiological functions of protein persulfidation remains large. In this mini-review, we discussed the specific regulatory mechanism of persulfidation on guard cell abscisic acid (ABA) signaling and the possible link of persulfidation, sulfenylation, and S-nitrosylation within the framework of redox-based regulation.