G蛋白位于H_2O_2上游参与H_2S诱导的拟南芥气孔关闭过程  

G-Protein Acts Upstream of H_2O_2 in Mediating H_2S-Induced Stomatal Closure in Arabidopsis thaliana

作　　者：张丹丹[1] 车永梅[1] 侯丽霞[1] 赵方贵[1] 刘新[1] 

机构地区：[1]山东省高校植物生物技术重点实验室,青岛农业大学生命科学学院,山东青岛266109

出　　处：《植物生理学报》2013年第2期181-187,共7页Plant Physiology Journal

基　　金：国家自然科学基金(30970228和31170237);山东省自然科学基金(ZR2010CM024);植物生理学与生物化学国家重点实验室开放课题(SKLPPBKF11001)

摘　　要：硫化氢(H2S)可诱导拟南芥气孔关闭。本文以拟南芥野生型及其G蛋白α亚基缺失突变体(Atgpa1-3、Atgpa1-4)和β亚基缺失突变体(Atagb1-1、Atagb1-2)为材料,研究了G蛋白在H2S诱导拟南芥气孔关闭中的作用及其与H2O2的关系。结果表明,H2S可诱导野生型拟南芥气孔关闭及G蛋白α亚基(GPA)和β亚基(AGB)基因表达量增加,但对Atgpa1-3、Atgpa1-4、Atagb1-1和Atagb1-2叶片气孔运动无显著影响;G蛋白激活剂霍乱毒素(CTX)增强H2S诱导拟南芥气孔关闭的作用,而其抑制剂百日咳毒素(PTX)能够阻断H2S的诱导作用,表明G蛋白参与H2S诱导的拟南芥气孔关闭过程。同时,H2S诱导野生型拟南芥叶片及气孔保卫细胞H2O2含量升高,但对Atgpa1-3、Atgpa1-4、Atagb1-1和Atagb1-2无显著作用。CTX促进拟南芥叶片及气孔保卫细胞中H2O2积累,而PTX抑制H2S引起的拟南芥叶片及气孔保卫细胞中H2O2含量的升高。由此说明,G蛋白位于HO上游参与HS诱导的拟南芥气孔关闭过程。Hydrogen sulfide （H2S） induces stomatal closure in Arabidopsis thaliana, hydrogen peroxide （H_2O_2） plays an important part in this procedure. In this paper, Arabidopsis wide type and its a subunit deficient mu- tants （Atgpal-3 and Atgpal-4） as well as 13 subunit deficient mutants （.4tagbl-1 and Atagbl-2） were used as materials, the effects of G-protein on H2S-induced stomatal closure and the relationship between G-protein and H202 were investigated. The results showed that H2S induced stomatal closure as well as the expression of G- protein a subunit （GPA） and 13 subunit （AGB） gens in leaves of Arabidopsis wild type, but had no significant ef- fects on stomatal movement in Atgpal-3, Atgpal-4, Atagbl-1 and Atagbl-2 mutants. GPA activator cholera toxin （CTX） improved H_2S-induced stomatal closure, but its inhibitors pertussis toxin （PTX） showed the oppo- site effect. These results manifested that G-protein was an signaling intermediate in H2S-induced stomatal clo- sure. H_2S induced increase in H_2O_2 content in leaves and guard cells ofA. thaliana wide type, but not in Atg- pal-3, Atgpal-4, Atagbl-1 and Atagbl-2 mutants. CTX enhanced H_2O_2 content in leaves and guard cells of Arabidopsis, but its inhibitor PTX was opposite. From these data it could be deduced that G-protein acts up- stream of H_2O_2 in mediatingH_2S-induce stomatal closure in Arabidopsis.

关 键 词：G蛋白 硫化氢 过氧化氢 气孔关闭 

分 类 号：Q945[生物学—植物学]