摘要： 为了研究气体信号分子硫化氢（H₂S）在拟南芥响应紫外胁迫过程中的作用，为H₂S及其相关制剂在农业生产中的应用提供理论依据，对抽薹期前的拟南芥野生型Col-0以及H₂S产生酶编码基因突变体lcd和des幼苗进行紫外处理20 min（波长254 nm，辐射强度60 μW/cm²），之后分别在光照和黑暗条件下用生理浓度外源H₂S（5 μmol/L）处理24 h，检测植株MDA、叶绿素含量、光合特性指标（净光合速率、蒸腾速率、气孔导度和胞间二氧化碳浓度）以及谷胱甘肽合成酶和DNA损伤修复相关酶编码基因的相对表达变化。结果表明：H₂S在光照或黑暗条件下都可降低紫外处理引起的MDA升高；在黑暗培养下增加叶绿素a、叶绿素b和总叶绿素含量；缓解紫外照射引起的蒸腾速率（Tr）下降；促进GSH2和PARP1基因的表达量。生理浓度H₂S通过促进谷胱甘肽合成基因的表达缓解紫外胁迫对拟南芥幼苗造成的氧化损伤，促进DNA损伤修复基因的表达，以维持拟南芥正常生长，且光照对该过程有一定的促进作用。

关键词: 硫化氢, 拟南芥, 紫外胁迫, 氧化损伤

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

中图分类号: 

• Q947