Hydrogen sulfide improves drought resistance in Arabidopsis thaliana
Zhuping Jin^{1, 2}, Guangdong Yang³, Rui Wang⁴*, Yanxi Pei^1*

¹ School of Life Science, Shanxi University, Taiyuan 030006, China.
² School of Chemical Engineering and Enviroment, North University of China, Taiyuan 030051, China.
³ School of Kinesiology, Lakehead University, Thunder Bay P7B 5E1, Canada.
⁴ Department of Biology, Lakehead University, Thunder Bay P7B 5E1, Canada.
^*Corresponding Author：Tel: 86-351-7018161 E-mail: peiyanxi@sxu.edu.cn 

Abstract
Hydrogen sulfide plays a crucial role in human and animal physiology. Its ubiquity and versatile properties have recently caught the attention of plant physiologists and biochemists. L-CD and D-CD, were identified as being mainly responsible for the degradation of cysteine in order to generate H₂S. This study investigated the expression regulation of these genes and their relationship to drought tolerance in Arabidopsis. First, the expression pattern of CDes in Arabidopsis was investigated. The expression levels of CDes gradually increased in an age-dependent manner. The expression of CDes was significantly higher in stems and cauline leaves than in roots, rosette leaves and flowers. Second, the protective effect of H₂S against drought was evaluated. The expression pattern of CDes was similar to the drought associated genes induced by dehydration, and H₂S fumigation was found to stimulate further the expression of drought associated genes. Drought also significantly induced increased H₂S production, a process that was reversed by re-watering. In addition, seedlings after treatment with NaHS (a H₂S donor) showed a higher survival rate and displayed a significant reduction in the size of the stomatal aperture compared to the control. These findings provide evidence that H₂S, as a gasotransmitter, improves drought resistance in Arabidopsis.

Key words: Hydrogen sulfide, gasotransmitter, Cysteine desulfhydrase, drought, Arabidopsis thaliana