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...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.展开更多
文摘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.
