H2S mediated balance regulation of stomatal and non-stomatal factors responding to drought stress in Chinese cabbage

Wenze Zhang, Jiao Zhang, Yanxi Pei, Zhuping Jin
School of Life Science, Shanxi University, Taiyuan, Shanxi Province 030031, China

Increased evidence has shown that hydrogen sulfide (H2S), a novel gasotransmitter, could enhance drought resistance in plants by inducing stomatal closure, with concurrent enhancement of photosynthetic efficiency, but little is known about the mechanism behind this contradictory phenomenon. This study examined the regulating mechanism of H2S in response to drought stress from stomatal and non-stomatal factors in Chinese cabbage. The results showed that H2S could increase photosynthetic efficiency and alleviate the damage caused by drought stress. It also regulated the expression and the activity of BrRuBisCO under drought stress, which was found to be modified by S-sulfhydration. The fluxes of Cl−, K+, and H+ in the guard cells were detected by non-invasive micro-test techniques (NMT) techniques while under drought stress. The results indicated that H2S signaling induced a transmembrane Cl− and H+ efflux and inhibited K+ influx, and the Cl− channel was the main responders for H2S-regulated stomatal movement. In conclusion, H2S signal not only activated the ion channel proteins located in the guard cell membrane to induce stomatal closure, but also regulated the transcriptional expression and the activity of RuBisCO, a non-stomatal factor to enhance the photosynthetic efficiency of leaves.