【摘要】 研究了外源多胺及其代谢抑制剂灌根处理对盐胁迫下耐盐性不同的2年生‘冬枣’(耐盐性弱)、‘金丝小枣’(耐盐性强)嫁接苗叶片生长发育、光合作用、叶绿体内离子稳态、类囊体膜H+-ATP酶活性及结合态多胺水平的影响。结果表明:120 mmol.L-1NaCl胁迫30 d,0.75 mmol.L-1的3种外源多胺均可提高两个枣品种(特别是耐盐性弱的冬枣)的单叶重、叶绿素含量和叶片光合速率,Put、Spd效应均显著,Spm效应较小;枣叶叶绿体中不同种类多胺之间存在显著转化关系,Put对枣叶无毒害作用,且是其它多胺发挥效应的基础。应用多胺合成抑制剂DFMO和MGBG以及其降解抑制剂AG的试验结果进一步证实前述结果。外源多胺提高盐胁迫下枣叶类囊体膜结合态多胺水平,显著抑制盐胁迫下枣叶类囊体膜H+-ATPase活性下降,增强枣叶类囊体膜对盐分离子进出的调控,使枣叶叶绿体中能够保持稳定的K+含量、显著为低的Na+含量和较高的K+/Na+,使盐胁迫下叶绿体中的离子稳态得到维护。更多还原

【Abstract】 The effects of exogenous polyamines and polyamine metabolism inhibitors on and chloroplast ionic homeostasis and thylakoid membrane conjugated H+-ATPase activity of Ziziphus jujuba Mill.species("Dongzao" havingweaker salt tolerance,"Jinsixiaozao" having stronger salt toleranec) grafted seedlings under salt stress in the aspects of leaves growth,photosynthesis,chloroplast ionic homeostasis,thylakoid membrane conjugated H+-ATPase activity and conjugated polyamine were studied.The results show that all the three kinds of exogenous polyamines(0.75 mmol·L-1) raised the two Chinese jujube cultivars’ single leaf weight,leaf chlorophyll content and photosynthetic rateunder 120 mmol·L-1 NaCl stress for 30 days,the effects both exogenous Put and Spd were significant while the effect of Spm were relative small;Significant transformation relationship was found among different polyamines in leaf chloraplast of Chinese jujube,and Put was not only no damage to leaves but also was the foundation ofphysiological effect of other polyamindes.Polyamine application effects antecedent were confirmed by using polyamine synthesis inhibitors DFMO and MGBG and polyamine degradation inhibitor AG.Further,the analysis results show that the mechanism of these physiological effectsof exogenous polyamines are as follows:exogenous polyamines increased conjugated polyamine level of thylakoid membrane of Chinese jujube cultivars with different salt tolerance,significantly inhibited the decrease of H+-ATPase activity of thylakoid membrane,enhanced the regulation of thylakoid membrane to salt ions in and out of chloroplasts,which can maintain stable K+ content,significantlydecreased Na+ content and significantly increased K+/Na+ ratio in leaf chloroplasts of the tree under salt stress.更多还原