Abstract: We used the plantlets of Chorispora bungeana, which wasan alpine subnival plant species,to study the membrane system damage induced by exogenous hydrogen sulfide (H₂S) during the response of mannitol (with the concentration of 0.3M) to simulate drought stress. We studied the contents of osmotic adjustment substances, the activities of antioxidant enzymes system, the phospholipase D (PLD), reactive oxygen species (ROS) and signaling molecule H₂S in response to drought stress, and the possible signaling relationship of PLD,ROS and H₂S was also discussed. NaHS, the exogenous H₂S donor, significantly reduced the electrolyte leakage rate and MDA content,enhanced the osmotic adjustment substances and the activities of antioxidant enzymes, suppressed the production of ROS, and improved the drought resistance of C.bungeana. The PLD activity, H₂S content and ROS could be induced significantly under drought stress.Under drought stress, the release of H₂S can be promoted significantly with applying the PA (downstream product of PLD) and H₂O₂ (ROS donor) separately. However, there was no significant effect on H₂S content under drought stress with adding DPI (Both PA and ROS inhibitor) simultaneously. The production of H₂S was significantly inhibitedunder drought stress,when 1-butanol (PLD inhibitor) and DPI (ROS inhibitor) were simultaneously applied. Therefore, ROS were located at the upstream of PLD and downstream of H₂S in C.bungeana under drought stress.

Key words: Chorispora bungeana, drought stress, hydrogen sulfide, signal relationship