SO_2诱导拟南芥保卫细胞凋亡  

SO_2 Induces Programmed Cell Death in Arabidopsis Guard Cells

作　　者：仪慧兰[1] 仪民[1] 吴婷[1] 

机构地区：[1]山西大学生命科学与技术学院,山西太原030006

出　　处：《山西大学学报（自然科学版）》2009年第4期621-626,共6页Journal of Shanxi University(Natural Science Edition)

基　　金：国家自然科学基金(30470318;30870454);高等学校博士学科点专项科研基金项(20070108007)

摘　　要：以拟南芥叶片下表皮为材料,研究了SO2体内衍生物-亚硫酸钠和亚硫酸氢钠混合液(3:1,mmol.L-1/mmol.L-1)对气孔保卫细胞的致死效应.结果表明,浓度1.0～5.0mmol.L-1的SO2衍生物处理表皮3h可引起保卫细胞死亡,死细胞出现核固缩、核断裂、凋亡小体等典型的核凋亡特征,且胁迫组细胞内活性氧和钙离子水平升高.蛋白酶抑制剂Z-Asp-CH2-DCB和TLCK能减少SO2衍生物诱导的细胞凋亡;过氧化氢酶(CAT)、抗坏血酸(AsA),及Ca2+螯合剂乙二醇双四乙酸(EGTA)和Ca2+通道抑制剂LaCl3均可使SO2衍生物诱发的细胞死亡率降低.0.1mmol.L-1的AsA或EGTA能降低胁迫组胞内的活性氧和Ca2+水平,与死亡率降低相伴发生.以上结果表明,一定浓度的SO2可诱导拟南芥保卫细胞凋亡,胁迫可能通过诱导活性氧产生、胞外钙内流,造成胞内Ca2+浓度升高,引发细胞程序性死亡.The effect of SO2 derivatives on guard cell death was investigated in Arabidopsis thaliana. The results showed that SO2 derivatives,a mixture of sodium sulfite and sodium bisulfite（3 ： 1,mmol · L^-1/ mmol· L^-1） ,significantly induced cell death in a concentration range of 1 to 5 mmol · L^-1. Programmed cell death （PCD） occurred after epidermal strips exposed to SO2 derivatives for 3 h,while reactive oxygen species （ROS） and Ca^2＋ levels increased within guard cells. However, the percentage of the cell death decreased when the strips exposed to SO2 derivatives combined with ascorbic acid （AsA,0.1 mmol · L^-1） or catalase（CAT,200 U ·mL^-1）. The cell death percentage also decreased after the strips exposure to SO2 derivatives combined with EGTA （Ca^2＋ chelator,0.1 mmol · L^-1） or LaCl3 （Ca^2＋ channel blocker,0.1 mmol · L^-1）. Both AsA and EGTA decreased cell death, which associated with a decrease of intracellular ROS and Ca^2＋ levels increased by SO2 exposure. Benzyoxycarbonyl-Asp-2, 6-dichlorobenzoyloxymethylketone （Z-Asp-CH2-DCB） and N-tosyl-L-lysine chloromethylketone （TLCK） decreased cell death at concentration of 0.1 μmol · L^-1. The results of the present study indicate that SO2 causes programmed cell death in A. thaliana via reactive oxygen species （ROS） production. ROS activates plasma membrane Ca^2＋ channels, leads to Ca^2＋ influx and an increase of intracelluar Ca^2＋ level,and induces finally cell death.

关 键 词：拟南芥 保卫细胞 SO_2 细胞凋亡 活性氧 CA^2+ 

分 类 号：Q945.7[生物学—植物学] X503.23[环境科学与工程—环境工程]