【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.更多还原

【Abstract】 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 equa- tion with a Ki of (1.94±0.11) mmol/L. Varying the luminal Mg2+concentration had no effect on SV cur- rents. These results will provide an important basis at channel level for the further research of the effects of magnesium on physiological activities of plants.更多还原