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.