H2S synthetase AtD-CDes involves in ethylene and drought regulated stomatal movement

The endogenous hydrogen sulfide (H2S), as a new gasotransmitter, participates in many plant physiological processes. In this study, we found that both ethylene and drought strongly induced H2S synthetase AtD-CDes gene expression and enzymatic activity. H2S synthesis inhibitors restrained the ethylene and drought induced stomatal closure in Arabidopsis. The H2S synthetase mutant Atd-cdes was insensitive to ethylene and drought, and overexpression of AtD-CDes conferred the transgenic plants more sensitive to ethylene and drought. Sequence analysis of AtD-CDes promoter showed that it contained ethylene response cis element ERE, and abiotic stress responsive cis elements MBS, LTR, and ABRE. The AtD-CDes promoter fused with GUS was transformed into Arabidopsis thaliana to get AtD-CDes promoter::GUS transgenic plants. When treated with ethylene and drought stress, the enzymatic activity of β-glucuronidase was higher in the leaves and stomata of transgenic Arabidopsis. Analyses of GUS activity from the transgenic plants harboring different fragments of the promoter shows that the key section of AtD-CDes promoter response to ethylene was from the -697 to -408 bp, and the key section response to drought stress was from -90 to -1 bp. These results suggested that the H2S produced from AtD-CDes may mediate ethylene and drought-induced stomatal movement.