Abstract: In order to explore the role of H₂S in Arabidopsis responsing the UV stress, so as to provide theoretical basis for the application of H₂S and its source material in agricultural production practice, the Col-0 (WT), lcd and des (the mutants of H₂S generating enzymes coding genes) seedlings of Arabidopsis before bolting were irradiated with UV (λ=254 nm, radiation intensity=60 μW/cm²)for 20 minutes firstly, then treated with or without exogenous H₂S (5 μmol/L) under nature light or dark for 24 h. The MDA and chlorophyll content, photosynthetic characteristics (net photosynthetic rate, transpiration rate, stomatal conductance and intercellular CO₂ concentration), as well as the relative transcription level of glutathione synthesis coding genes and DNA repair related enzymes coding genes were measured. The results indicated a physiological concentration of H₂S, under the dark or illumination condition,could anesis the MDA rising and transpiration rate decreasing caused by UV, and increase the content of chlorophyll as well as the transcription level of GSH2 and PARP1 gene.The conclusion is that a physiological concentration of H₂S could alleviate the damage on Arabidopsis seedlings caused by UV stress by promoting the genes expression of GSH synthetase, and maintained the normal growth of Arabidopsis by promoting the genes expression of DNA repair enzyme, and light played an auxo-action on this process.

Key words: Hydrogen sulfide, Arabidopsis thaliana, UV stress, Oxidative damage

CLC Number: 

• Q947