用膜片钳研究CuCl2对萝卜液泡膜SV通道的影响

用膜片钳全液泡记录方式研究了CuCl2对萝卜SV通道的影响.研究表明,SV通道为阳离子选择性通道,细胞质钙可激活此通道,且其表现出钙依赖性.细胞质钙达2mmol/L时,SV通道电流基本上达到饱和.当在外液中加入不同浓度的CuCl2时,SV通道电流有明显的变化.高浓度的铜离子对通道电流有抑制作用,而低浓度(<0.1mmol/L)则增强通道电流.电极内液中的CuCl2对SV通道电流也有抑制作用.这为进一步研究铜离子对植物生理活动的影响以及铜肥对农作物的作用在通道水平上提供重要的依据.

Effects of CuCl2 on Slow Vacuolar Ion Channels in Radish by Patch-clamp

The action mechanism of Cu 2+ to Slow Vacuolar(SV) channels of Radish(Raphanus satirus L.) was investigated by using whole-vacuolar patch-clamp recording mode. It is shown that SV channel was a cation selective channel and it had voltage- and time-dependence. Cytoplasmic Ca 2+ could activate SV channel and the increase in cytoplasmic Ca 2+ led to enhancement of SV-type currents. The changes of SV current was shown after Cu 2+ with different concentrations was added to the bath. When CuCl2 with different concentrations was added to the bath solution, SV currents have different effects. It was found that CuCl2 with a lower concentration(<0.1 mmol/L) promoted the channel currents, while CuCl2 with a higher concentration(>0.1 mmol/L) inhibited SV currents. When 1 μmol/L CuCl2 was added to pipette solution, SV currents were inhibited remarkably. This result provides an important basis at the channel level for researching further the effects of Cu 2+ on physiological activities of plants and the effects of copper fertilizers on crops.