镧对蚕豆叶肉细胞质膜外向钾通道作用研究  

Effects of La^(3+) on Outward K^+ Channels at Plasma Membrane in Vicia Mesophyll Cells

作　　者：薛绍武[1] 杨频[1] 

机构地区：[1]山西大学分子科学研究所

出　　处：《高等学校化学学报》2005年第1期16-18,共3页Chemical Journal of Chinese Universities

基　　金：国家自然科学基金 (批准号 :2 9890 2 80 );山西省科学基金项目资助

摘　　要：The effects of La 3+ on outward K+ channels at plasma membrane in vicia mesophyll cells were studied by using the whole-cell patch-clamp recording mode. It was shown that La 3+ on both sides of plasma membrane blocked outward K+ currents in a concentration-dependent manner. The dose response was fitted by the Michalis- Menten relationship characterized by an inhibitory constant K i of (76.59±9.28) μmol/L(outside membrane) and (5.80±0.62)×10 -15 mol/L(inside membrane) respectively, suggesting that intra-cellular La 3+ had a stronger inhibitory effect on outward K+ currents than extra-cellular La 3+ did. Since K+ remains the dominant osmoticum in mesophyll cells, the inhibition of outward K+ currents by La 3+ may contribute greatly to preventing the K+ loss and promoting turgor maintenance. These results implied that rare earth elements might have potential practical values in regulating plant water status and strengthening plant drought endurance.The effects of La 3+ on outward K+ channels at plasma membrane in vicia mesophyll cells were studied by using the whole-cell patch-clamp recording mode. It was shown that La 3+ on both sides of plasma membrane blocked outward K+ currents in a concentration-dependent manner. The dose response was fitted by the Michalis- Menten relationship characterized by an inhibitory constant K i of (76.59±9.28) μmol/L(outside membrane) and (5.80±0.62)×10 -15 mol/L(inside membrane) respectively, suggesting that intra-cellular La 3+ had a stronger inhibitory effect on outward K+ currents than extra-cellular La 3+ did. Since K+ remains the dominant osmoticum in mesophyll cells, the inhibition of outward K+ currents by La 3+ may contribute greatly to preventing the K+ loss and promoting turgor maintenance. These results implied that rare earth elements might have potential practical values in regulating plant water status and strengthening plant drought endurance.

关 键 词：膜片钳全细胞记录 叶肉细胞 外向钾通道 LA^3+ 

分 类 号：O614.33[理学—无机化学]