铕离子对萝卜液泡通道影响的膜片钳法研究

Study on Eu^(3+) on Channels in Radish (Raphanus satirus L.) Vacuoles by Patch-clamp

[目的]从离子通道水平讨论作为稀土微肥的Eu3+对萝卜液泡生理活动的影响。[方法]用膜片钳全液泡记录方式研究讨论了膜内外Eu3+对萝卜(Raphanus satirus L.)慢液泡(SV)通道电流的影响。[结果]外液中存在EGTA和EuCl3时,通道电流被显著抑制;当外液中不含EGTA而同时含有CaCl2和不同浓度的EuCl3时,通道电流又被不同程度的增大,且随着Eu3+浓度的增加,通道电流逐渐降低;而Eu3+在膜内与SV通道作用机理的研究表明,Eu3+浓度高时抑制通道电流,浓度低时则促进通道电流。[结论]本文的研究结果为进一步研究Eu3+对植物生理活动的影响和Eu3+作为稀土微肥在农作物中的最佳用量在通道水平上提供了重要的依据。

[Objective] The effects of Eu^3＋ as rare earth fertilizers on physiological activities of plants were discussed at channel level. [Method] By using the whole -vacuolar patch -clamp recording mode, effects of cytosolic and luminal Eu^3＋ on SV -type channel currents of radish vacuoles were studied and discussed. [Result] When EGTA and EuCl3 were added to bath solutions, SV-type currents were suppressed remarkably. When bath solutions containing both CaCl2 and EuCl3 with different concentrations but free of EGTA, it was found that cytosolic Eu^3＋ had different promoting effects on SV channels. With the increase of the concentrations of Eu^3＋, SV -type currents decreased gradually. Finally the effects of luminal Eu^3＋ with different concentrations on the channel currents were studied in detail. It was found that EuCl3 with higher concentrations had strong inhibitory effect on SV currents, while EuCl3 with lower concentrations promoted channel currents. [Conclusion] These results provided an important basis at channel level for the further research onthe effects of Eu^3＋ on physiological activities of plants and the optimum amounts of Eu^3＋ on crops as rare earth fertilizers.