H2S巯基化修饰蛋白质调节谷子响应逆境胁迫

气体信号分子硫化氢（H2S）通过对蛋白质巯基化修饰参与动物体内许多重要的生理活动，但是在植物中该方面的报道甚少. 本论文证明，H2S信号提高蛋白质的巯基化水平参与谷子（foxtail millet）对低温、高温、盐、渗透和紫外胁迫的响应. 用5种方式4℃、42℃、NaCl、PEG和UV处理，引起谷子H2S产生速率和内源H2S含量的升高. 实时荧光定量PCR检测上述5种处理后谷子幼苗H2S产生酶基因Lcd1、Lcd2、Dcd1、Dcd2和Des的表达，Lcd1受盐、低温和渗透胁迫诱导；Lcd2受高温、低温和渗透胁迫诱导；Dcd1受盐诱导；Dcd2和Des受低温诱导；UV处理后5个酶基因表达均下降. Western 印迹检测表明，外源H2S熏蒸和5种胁迫处理引起谷子幼苗蛋白质巯基化水平升高. 上述结果证明，H2S信号通过提高蛋白质的巯基化水平参与谷子对低温、高温、盐、渗透和紫外胁迫的响应.

H2S Regulates Foxtail Millet Responsing to Stress by Protein S-sulfhydration

Hydrogen sulfide (H2S), as a gasotransmitter star, has been reported to involve in multiple important physiological activities of animals and in the response of plants to various stresses. H2S addition to Cys thiol in proteins (S-sulfhydration) has just recently been reported, as one of its regulating operation in animals. Owing to its high tolerance to adversity, the emerging model organism foxtail millet was recruited in this study to detect the response of H2S signaling to low temperature, heat, salt, osmotic and UV stress. The H2S production rate and H2S content of the seedlings were increased when they were suffered from the condition of low temperature (4℃), high temperature (42℃), NaCl, PEG, or UV, compared with the untreated ones. Except the UV stress, other managements mentioned above up-regulated the expression of H2S synthase coding genes LCD1, LCD2, DCD1, DCD2 and DES to some degrees. Additionally, both five kinds of treatment and exogenous H2S fumigation significantly enhanced the S-sulfhydration of total proteins, as an important post-translational modification. These results suggested that H2S signaling participated in plants response to these stresses by mediating protein S-sulfhydration.