盐胁迫对不同耐盐性枣树品种根系和叶片中多胺含量及多胺氧化酶活性的影响

Polyamine Contents and Polyamine Oxidase Activities in Roots and Leaves of Two Jujube (Ziziphus jujuba Mill.) Cultivars with Contrary Salt Tolerance under Salt Stress

摘要:

为探讨枣(Ziziphus jujuba Mill.)树中多胺及多胺氧化酶活性与其耐盐性的关系,对耐盐性强的‘金丝小枣’和耐盐性弱的‘冬枣’2 年生苗中不同状态和种类的多胺和多胺氧化酶活性进行了研究.结果表明,在120 mmol L^-1 NaCl 盐胁迫下,枣树根系和叶片中的多胺含量升高,耐盐性强的品种的上升幅度显著大于耐盐性弱的品种；随着盐胁迫时间的延长,根系和叶片中多胺含量逐渐降低,耐盐性弱的品种的降低幅度显著大于耐盐性强的品种,叶中的多胺含量的降低幅度大于根中的,结合态多胺的降低幅度大于游离态多胺的、精胺和亚精胺的降低幅度大于腐胺的；两个品种根系和叶片中多胺氧化酶(PAO)活性均明显高于二胺氧化酶(DAO)活性,盐胁迫下耐盐性弱的品种酶活性增强幅度显著大于耐盐性强的品种.这些说明,枣树品种的耐盐性与其内源多胺的组成、含量有关,多胺氧化酶的种类与活性对盐胁迫的响应也密切相关,多胺积累有利于提高枣树品种的耐盐性.

Abstract:

In order to investigate the relationship between salt tolerances of jujube cultivar and polyamine and polyamine oxidase, the polyamine contents and polyamine oxidase activities in two-year-old plants of ‘Jingsixiaozao’ with strong salt tolerance and ‘Dongzao’ with weak salt tolerance were studied. The results showed that under 120 mmol L^-1 NaCl salt stress, the polyamine contents in roots and leaves of two jujube cultivars enhanced, and increase degree of ‘Jingsixiaozao’ was significantly larger than that of ‘Dongzao’. As the extension of salt stress days, polyamine contents of roots and leaves decreased, and the decrease degree was in the order as: ‘Dongzao’ > ‘Jingsixiaozao’, leaves > roots, conjugated polyamines > free polyamines, spermine > spermidine, respectively. The activities of polyamine oxidases (PAO) were higher than that of diamine oxidases (DAO) in roots and leaves of the two jujube cultivars, the increase degree of weak salt tolerant cultivar ‘Dongzao’ was much greater than that of strong salt tolerant cultivar ‘Jingsixiaozao’ under salt stress. These indicate that salt tolerance of jujube cultivar has close correlation with composition and content of endogenous polyamines, and activity of polyamine oxidases. So, It is suggested that polyamine accumulation is beneficial to enhance salt tolerance of jujube cultivar.