Hydrogen sulfide modulates flagellin-induced stomatal immunity.

Area of Science:

• Plant immunity
• Plant physiology
• Molecular biology

Background:

• Stomata are plant pores essential for gas exchange but also serve as pathogen entry points.
• Guard cells detect pathogen-associated molecular patterns (PAMPs) to trigger stomatal closure and prevent microbe invasion.

Purpose of the Study:

• To investigate the role of hydrogen sulfide (H2S) and L-CYSTEINE DESULFHYDRASE 1 (DES1) in plant stomatal immunity.
• To determine the involvement of H2S and DES1 in responses to flagellin (flg22) and bacterial pathogens.

Main Methods:

• Utilized Arabidopsis (Arabidopsis thaliana) as a model organism.
• Generated and analyzed knockout mutants for the DES1 gene.
• Assessed stomatal closure, reactive oxygen species (ROS) production, and susceptibility to Pseudomonas syringae pv. tomato (Pst) infection.

Main Results:

• H2S and DES1 were found to be involved in flg22- and bacterial-induced stomatal closure and ROS modulation.
• DES1 knockout mutants showed reduced susceptibility to Pst and lower H2O2 levels upon flg22 treatment.
• H2S independently induced cytosolic H2O2 in guard cells, independent of RBOHD activity.

Conclusions:

• Hydrogen sulfide (H2S) and its cytosolic source, DES1, are critical components of the plant stomatal immune response.
• H2S and DES1 play significant roles in defending against microbial pathogens by modulating stomatal closure and ROS production.