磷脂酰肌醇3-磷酸对UV-B诱导蚕豆保卫细胞中过氧化氢产生和气孔关闭的影响  

Effect of Phosphatidylinositol 3-Phosphate on UV-B-Induced H_2O_2 Production in Guard Cells and Stomatal Closure of Broad Bean

作　　者：李惠民[1,2] 胡洁[1] 贺军民[1] 

机构地区：[1]陕西师范大学生命科学学院,西安710062 [2]商洛职业技术学院,陕西商洛726000

出　　处：《中国农业科学》2013年第20期4246-4253,共8页Scientia Agricultura Sinica

基　　金：国家自然科学基金项目(31170370);中央高校基本科研业务费项目(GK200901013)

摘　　要：【目的】研究磷脂酰肌醇3-激酶(PI3K)催化产物磷脂酰肌醇3-磷酸(PI3P)对紫外线B(UV-B)诱导保卫细胞中过氧化氢(H2O2)产生和气孔关闭的影响,为进一步阐明植物细胞转导UV-B辐射信号的机制提供依据。【方法】以蚕豆(Vicia faba L.)表皮条为材料,采用PI3K的抑制剂沃曼青霉素(WM)和LY294002(LY)来抑制PI3P的形成,采用二苯基碘(DPI)和水杨基氧肟酸(SHAM)分别抑制H2O2形成的NADPH氧化酶途径和细胞壁过氧化物酶途径,通过气孔开度分析和激光扫描共聚焦显微镜技术,确定PI3P在0.8 W·m-2UV-B辐射诱导蚕豆保卫细胞H2O2产生和气孔关闭中的作用。【结果】WM和LY能显著抑制UV-B诱导的保卫细胞H2O2产生和气孔关闭;外源H2O2处理能显著逆转WM和LY对UV-B诱导气孔关闭的抑制效应,但WM和LY不能抑制外源H2O2诱导的气孔关闭;UV-B诱导的保卫细胞H2O2产生和气孔关闭能被活性氧清除剂和SHAM显著抑制,但不能被DPI抑制。【结论】PI3P通过诱导蚕豆保卫细胞中产生于过氧化物酶途径的H2O2形成来介导UV-B辐射诱导的气孔关闭。[ Objective] The role of phosphatidylinositol 3-phosphate （PI3P）, the product of phosphatidylinositol 3-kinase （PI3K）, in UV-B-induced hydrogen peroxide （H202） generation in guard cells and stomatal closure was analyzed to provide valuable evidence for further elucidating the mechanism of UV-B signaling transduction in plants. [ Method ] By using PI3K inhibitors wortmannin （WM） and LY294002 （LY） to inhibit the production of PI3P, and by using diphenylene iodonium （DPI） and salicylhydroxamic acid （SHAM） to inhibit H202 production via NADPH oxidase pathway and peroxidase pathway respectively, the role of PI3P in 0.8 W, m-2 UV-B-induced H202 production in guard cells and subsequent stomatal closure was studied via stomatal bioassay and laser-scanning confocal microscopy in epidermal strips of broad bean （Vicia faba L.）. [ Result ] Both the UV-B-induced H202 production in guard cells and stomatal closure were significantly inhibited by WM and LY. Exogenous H202 rescued the inhibitory effect of WM and LY on UV-B-induced stomatal closure, but exogenous H2Oz-induced stomatal closure was not inhibited by WM and LY. Both the UV-B-induced H202 production in guard cells and stomatal closure were significantly inhibited by the reactive oxygen species scavenger and SHAM, but not inhibited by DPI. [Conclusion] PI3P mediates UV-B-induced stomatal closure via activating the peroxidase-dependent H202 production in guard cells of broad bean.

关 键 词：磷脂酰肌醇3-磷酸 蚕豆 过氧化氢 紫外线B辐射 气孔运动 

分 类 号：S643.6[农业科学—蔬菜学]