NaCl胁迫对骆驼蓬幼苗液泡膜H^＋-ATPase和H^＋-PPase活性的影响

Effects of NaCl Stress on Tonoplast H^+-ATPase and H^+-PPase Activities in Peganum harmala Seedlings

研究了不同浓度NaCl胁迫对骆驼蓬幼苗Na+、K+含量及液胞膜H+-ATP酶(H+-ATPase)和H+-焦磷酸酶(H+-PPase)活性的影响。结果表明,NaCl胁迫浓度的增加使骆驼蓬幼苗根、叶中的K+含量下降,Na+含量和Na+/K+比及K+对Na+的吸收和运输选择性增高;根、叶液胞膜H+-ATPase和H+-PPase活性升高,H+-ATP酶耦联比率无显著变化;根液胞膜依赖ATP和PPi的质子泵活性及Na+/H+逆向转运活性先升后降,叶依赖ATP的质子泵活性及Na+/H+逆向转运活性升高,依赖PPi的质子泵活性先升后降。说明液泡膜H+-ATPase和H+-PPase驱动的质子泵和Na+/H+逆向转运活性对Na+在液泡内的积累及其骆驼蓬的耐盐性起重要作用。

Effects of the different concentration of NaCl stress on Na＋ and K^＋ contents,tonoplast H^＋-ATPase and H^＋-PPase activities in peganum harmala seedling leaves were studied.The results showed that with NaCl stress concentration increased,K^＋ content in roots and leaves was decreased,but Na^＋ content,Na^＋/K^＋ ratio,K^＋/Na^＋ selectivity,as well as tonoplast H^＋-ATPase and H^＋-PPase activities were all increased,the H^＋/substrate stoichiometry was significantly unchanged,the activities of the ATP-dependent proton pump and the Na^＋/H^＋ antiport in leaves were increased,the activities of PPi-dependent proton pump in leaves and ATP and PPi-dependent proton pump and Na^＋/H^＋ antiport of the tonolast vesicles in roots were all increased and then decreased with the increase of NaCl concentration.These results indicated that the activity of Na^＋/H^＋ antiport and proton pump driven by H^＋-ATPase and H^＋-PPase in tonoplast of P.harmala plays an important role in Na^＋ accumulation in vacuoles and salt tolerance.