中文摘要：

以拟南芥为实验材料,利用分光光度法、显微观测法及药理学实验,研究了镉（Cd^2＋）、硫化氢（H2S）和脱落酸（ABA）处理对拟南芥野生型（wild type,WT）、abi5和lcd气孔运动的影响,以及H2S合成酶L-半胱氨酸脱巯基酶（LCD）的活性和体内H2S含量的变化。结果表明：光照条件下,随着Cd^2＋浓度的增加,野生型拟南芥气孔孔径逐渐减小,LCD的活性及内源H2S含量依次升高。200μmol/L的CdCl2可以减小abi5的气孔开度,且50μmol/L的H2S也可以减小abi5和WT的气孔开度,而ABA并不能减小abi5的气孔开度,说明Cd^2＋诱导的气孔关闭主要依赖H2S信号。实验进一步验证了这种现象：与WT相比,200μmol/L的CdCl2对LCD缺失突变体（lcd）气孔开度的影响不大,加入H2S的供体NaHS后,lcd气孔关闭。研究发现,Cd^2＋可通过增强LCD的活性,促进L-半胱氨酸分解生成H2S,进而诱导拟南芥气孔关闭。

英文摘要：

Through pharmacological combined with spectrophotography, we study the effects of Cd^2＋ , ABA and HzS on stomatal closure, L-cysteine desulfhydrase （LCD） activity and H2S generation in Arabidopsis thaliana. The results showed that as the concentration of Cd^2＋ increased under light condition, the stomatal closure was gradually increased in Arabidopsis. Cd^2＋ treatment increased LCD activity and induced Hz S generation. The stomatal closure was induced by 200 μmol/L CdCl2 or 50 μmol/L H2S in abi5, but ABA was not inoperative. The mutant lcd reduced Hz S generation and inhibited Cd^2＋-induced the stomatal closure compared with the WT. The results suggested that the accumulation of H2S via enhancing the LCD activity could finally induced the stomatal closure of Arabidopsis.