Hydrogen Sulfide and Posttranslational Modification of Proteins: A Defense Strategy Against Abiotic Stress

Hydrogen sulfide (H2S), as a signaling gasotransmitter, has been reported to be involved in the regulation of diverse biological processes. Nevertheless, the underlying H2S-regulated mechanisms in plant biological functions are poorly understood. A new way of post-translational modification of proteins, named persulfidation, was found and used to explain the core mechanism of H2S action. Persulfidation results in the modification of cysteine residues on target proteins, via conversion of the thiol group into a persulfide group. Persulfidated proteins exhibit functional changes in enzyme activities and therefore, modified cysteine can interact with several other proteins and expresses greater reactivity due to the increased nucleophilicity of persulfide compared with the thiol group. Persulfidation is believed to play crucial role in the protective mechanisms through affecting antioxidant system, autophagy, and stomatal closure. In the present chapter the importance of persulfidation in H2S-mediated plant adaptive responses to various abiotic stresses and methods for the detection of protein persulfidation are presented. Also, the crosstalk of H2S, NO, and ROS has been analyzed, especially in relation to posttranslational modification of proteins.