NaCl胁迫对盐芥质膜和液泡膜ATPase活性的影响

Changes of PM and TP ATPase Activities in Thellungiella Seedlings under Salt Stress

以盐生植物盐芥和中生植物拟南芥幼苗为材料，研究了盐胁迫对它们叶片和根质膜、液泡膜H^＋-ATPase、Ca^2＋-ATPases和K^＋-ATPase活性以及H^＋-ATPase、Na^＋／H^＋逆向转运蛋白表达的影响。结果显示：在NaCl胁迫下，盐芥叶片和根质膜的H^＋-ATPase活性分别比对照显著升高41％～212％和35％～53％，液泡膜的HtATPase分别显著升高281％～373％和4％～38％，而拟南芥却比相应对照都显著降低；相同盐浓度胁迫下，盐芥叶片的H^＋-ATPase活性比根部高4～8倍，盐芥根也远高于拟南芥。在NaCl胁迫下，盐芥叶片和根的液泡膜HtATPase蛋白质B亚基含量变化与其酶活性变化趋势一致，质膜Na^＋／H^＋逆向转运蛋白的表达量与Na^＋含量变化趋势一致。盐胁迫下盐芥根中Ca^2＋-ATPases和KtATPase活性的增加与根中Ca^2＋和K^＋含量呈显著正相关。研究发现，在盐胁迫条件下，盐芥能有效增强H^＋-ATPase蛋白和Na^＋／H^＋逆向转运蛋白表达，显著提高其根系与叶片质膜和液泡膜的H^＋ATPase、Ca^＋ATPase和K-1ATPase活性，维持细胞质中较高的Ca^＋和K^＋水平，从而缓解盐胁迫的伤害，增强耐盐性。

The effect of salt stress on the modification of plasma membrane （PM） and tonoplast （TIP） H^＋- ATPase activities in Thellungiella （Thellungiella halophila） and Arabidopsis seedlings were studied. Under 100-400 mmol·L^-1 NaCl stress, the H^＋-ATPase,Ca^2＋-ATPase and K^＋-ATPase activities in Thellungiella roots and leaves increased about 41%-212% ,35%-53% in PM and 281%-373%,4%-38% in TP than the untreated plant. Under the same NaC1 concentration stress,the H^＋-ATPase,Ca^2＋-ATPase and K^＋-ATPase activities in Thellungiella leaves were 4～8 times than those in its roots. The TP H^＋-AT- Pase 13 subunit Western blotting results showed the same increased level as the H^＋-ATPase activity in roots,and PM Na/I-t antiporter Western blotting results showed significant difference with the different Na＋ contents in its leaves and roots. Ca^2＋-ATpase and K^＋-ATpase activities were highly correlated with Ca^2＋ and K^＋ concentration in Thellungiella roots treated by NaCl. It suggested that Ca^2＋ was the second signal transduction in Thellungiella root and involved in feedback regulation of PM H^＋-ATPase. These results indicated that Thellungiella enhanced the salt resistant characteristic through increasing the roots and leaves H^＋ ATPase,Ca^2＋ ATPase and K^＋-ATPase activities.