Effects of La^(3+) on inward K^+ channels at plasma membr in guard cells  

作　　者：XUE Shaowu YANG Pin 

机构地区：[1]Institute of Molecular Science, Chemical Biology and Molecular Engineering Laboratory of Ministry of Education, Shanxi University, Taiyuan 030006, China Institute of Molecular Science, Chemical Biology and Molecular Engineering Laboratory of Ministry of Education, Shanxi University, Taiyuan 030006, China

出　　处：《Science China Chemistry》2005年第2期143-147,共5页中国科学（化学英文版）

基　　金：the National Natural Science Foundat ion of China(Grant No.20171031); the Shanxi Provincial Natural Science Foundation.

摘　　要：The effects of La3+ on inward K+ channels at plasma membrane in vicia guard cells are investigated using the whole-cell patch-clamp recording mode. It is shown that La3+ on both sides of plasma membrane blocks inward K+ currents in a concentration- dependent manner, indicating that La3+ binding sites may exist on both sides of plasma membrane in guard cells in vicia. The dose response is fitted by the Michaelis-Menten relation characterized by an inhibitor constant Ki of 2.56±0.25 μmol·L?1 (outside membrane) and (1.18±0.11)×10?15 mol·L?1 (inside membrane). Intracellular La3+ has much stronger inhibitory effect on inward K+ currents than ex- tracellular La3+ does, suggesting there may exist stronger binding sites inside membrane than outside membrane. Since ion channel activities of guard cells directly affect plant stomatal movement and water status, our results imply that rare earth elements might have potential practical values in regulating plant water status and strengthening plant drought endurance.The effects of La3+ on inward K+ channels at plasma membrane in vicia guard cells are investigated using the whole-cell patch-clamp recording mode. It is shown that La3+ on both sides of plasma membrane blocks inward K+ currents in a concentration- dependent manner, indicating that La3+ binding sites may exist on both sides of plasma membrane in guard cells in vicia. The dose response is fitted by the Michaelis-Menten relation characterized by an inhibitor constant Ki of 2.56±0.25 μmol·L?1 (outside membrane) and (1.18±0.11)×10?15 mol·L?1 (inside membrane). Intracellular La3+ has much stronger inhibitory effect on inward K+ currents than ex- tracellular La3+ does, suggesting there may exist stronger binding sites inside membrane than outside membrane. Since ion channel activities of guard cells directly affect plant stomatal movement and water status, our results imply that rare earth elements might have potential practical values in regulating plant water status and strengthening plant drought endurance.

关 键 词：WHOLE-CELL patch-clamp  GUARD cell  STOMATAL movements  INWARD K+ channels  La3+. 

分 类 号：N[自然科学总论]