枣品种耐盐性与叶片生物膜结合态多胺水平和H^+-ATP酶活性的关系

Relationship between Cultivar Salt Tolerance and Conjugated Polyamine Level and H^+-ATPase Activity in Leaf Biomembrane of Chinese Jujube(Ziziphus jujuba Mill.)

120mmol·L-1NaCl胁迫30d,耐盐性强的‘金丝小枣’叶片细胞质膜、液泡膜共价结合态腐胺(Put)、亚精胺(Spd)、精胺(Spm)含量及多胺(PAs)总水平与对照无显著性差异,但耐盐性弱的‘冬枣’叶片质膜共价结合态Put、Spd、Spm含量和PAs总水平及液泡膜Spd含量均显著降低;‘金丝小枣’叶片类囊体膜共价结合态Put含量、PAs总水平较对照显著降低,‘冬枣’则是Put、Spd、Spm含量及PAs总水平均显著降低。盐胁迫下,‘金丝小枣’叶片细胞质膜、液泡膜、类囊体膜非共价结合态Put、Spd、Spm含量及PAs总水平下降,但其中仅类囊体膜Spd含量显著低于对照,而‘冬枣’的3种膜上非共价结合态的这些多胺及其总水平均显著低于对照。与对照相比,盐胁迫下耐盐性不同的2个枣品种,叶片细胞质膜、液泡膜和类囊体膜H+-ATP酶活性均降低,但降低幅度因枣品种和生物膜种类不同而异,且H+-ATP酶活性与相应膜结合态多胺水平存在极紧密的正相关关系。结果表明,膜结合态多胺参与枣品种耐盐性的表达,调节盐胁迫下枣叶细胞中溶质的跨膜运输。

Contents of covalently conjugated putrescine（Put）,spermidine（Spd）,spermine（Spm） and total polyamines（PAs） in leaf plasma membrane and tonoplast membrane isolated from leaves of Ziziphus jujuba cv.＇Jinsixiaozao＇（salt tolerant） under salt stress of 120 mmol·L^-1 NaCl for 30 d were not significantly different from control（P≤0.05）,covalently conjugated Put,Spd,Spm and PAs content in leaf plasma membrane and Spd content in tonoplast membrane isolated from Z.jujuba cv.＇Dongzao＇（salt sensitive） leaves significantly decreased compared with control;contents of covalently conjugated Put and PAs in thylakoid membrane of ＇Jinsixiaozao＇ leaves were significantly lower than those of control,but contents of the Put,Spd,Spm and PAs in ＇Dongzao＇ leaves were all significantly lower than those of control.Contents of noncovalently conjugated Put,Spd,Spm and PAs in leaf plasma membrane,tonoplast membrane and thylakoid membrane isolated from ＇Jinsixiaozao＇ leaves decreased under salt stress,in which only Spd content in thylakoid membrane was significantly different from control,contents of Put,Spd,Spm and PAs in the three biomembranes isolated from ＇Dongzao＇ leaves were all significantly lower than those of control.Experimental results also showed that H＋-ATPase activities in leaf plasma membrane,tonoplast membrane and thylakoid membrane isolated from the two Chinese jujube cultivars decreased under salt stress compared with control,however,the decrease degrees differed in jujube cultivars and biomembrane species,and H＋-ATPase activity was significantly and positively correlated with conjugated polyamine level.The results strongly indicates that conjugated polyamine participates expression of salt tolerance of Chinese jujube cultivar,and regulates across-membrane translocation of substrates in leaves of jujube under salt stress.