Na+和Ca2+对拟南芥根原生质体质膜内向K+通道电流的影响

以拟南芥(Arabidopsis thaliana Columbia)根为材料，利用膜片钳技术测定其根细胞原生质体质膜内向K^ 电流，并对Na^ 对其K^ 电流的影响进行了初步研究，发现Na^2 可明显抑制拟南芥根细胞原生质体的内向K^ 电流，外施Ca^2 可缓解Na^ 对内向K^ 电流的抑制．说明Ca^2 参与了质膜上K^ 通道对K^ ／Na^ 的选择性吸收的调节，从而使植物适应盐胁迫．

Effects of Na+ and Ca2+ on the inward K+ current in the plasma membrane of Arabidopsis root cells

Using patch-clamp techniques,we examined the K~+ channel activity in the plasma membrane of root cells from Arabidopsis thaliana (ecotype Columbia) after NaCl treatment.Inward currents in the root cells were significantly decreased within 5 min after 50 mmol/L NaCl was perfused to the bath solution.However,addition of 5 mmol/L Ca~(2+) recovered the decrease of inward-rectifying current.These suggest that Ca~(2+) is involved in the regulation of selective uptake of Na~+/K~+ through K~+ channel in root cells under higher Na~+ concentration,leading to adaptation of plants to salt stress.