膜片钳法研究镁离子对萝卜液泡膜SV通道的影响  

Study of Magnesium Effects on Slow Vacuolar Ion Channel in Radish by Patch-Clamp Technique

作　　者：张朝峰[1] 杨频[1] 薛绍武[1] 

机构地区：[1]山西大学分子科学研究所化学生物学与分子工程教育部重点实验室,太原030006

出　　处：《化学学报》2005年第12期1147-1150,i006,共5页Acta Chimica Sinica

基　　金：国家自然科学基金(No.29890280)重大项目;山西省自然科学基金资助.

摘　　要：用膜片钳全液泡记录方式研究了Mg2+对萝卜(RaphanussativusL.)液泡膜上SV通道电流的影响.结果表明:用EGTA配位Ca2+后,胞质Mg2+不能够代替Ca2+来激活SV通道;外液中不同浓度的Mg2+对通道电流有抑制作用,并且呈一定的浓度依赖性,用Hill方程拟合浓度依赖性曲线,得抑制常数Ki=(1.94±0.11)mmol/L,而内液中的Mg2+不影响通道电流.这一结果为进一步研究镁对植物生理活动的影响从通道水平提供了重要依据.The effects of magnesium cation on slow vacuolar (SV) channel currents in radish were studied using, the whole-vacuole patch-clamp technique. In the presence of Ca2+ buffer EGTA, cytosolic Mg2+ could not activate SV currents instead of cytosolic Ca2+. Mg2+ added to bath solution caused a decrease of SV cur rents in a concentration-dependent manner. The concentration response curve could be fitted to a Hill equation with a K-i of (1.94 +/- 0.11) mmol/L. Varying the luminal Mg2+ concentration had no effect on SV currents. These results will provide an important basis at channel level for the further research of the effects of magnesium on physiological activities of plants.

关 键 词：液泡膜 膜片钳法 萝卜 离子对 MG^2+ CA^2+ 浓度依赖性 SV通道电流 镁 记录方式 EGTA 抑制作用 方程拟合 抑制常数 生理活动 胞质 

分 类 号：Q942.5[生物学—植物学]