低温胁迫下内源脱落酸对马尾松优良种源抗寒性的调节作用

Regulation of endogenic abscisic acid （ABA） for cold resistance of superior provenance Pinus massoniana under low temperature stress

关键词:  马尾松  种源  低温胁迫  ABA  保护酶  抗寒性

Key words:  Pinus massoniana  provenance  low temperature stress  ABA  protective enzymes  endogenic abscisic

摘要:

以2个马尾松优良种源苗期的叶片为材料，对系列低温梯度条件下不同种源叶片的内源ABA、内源保护酶系统的动态变化的规律以及相互作用进行研究。结果表明：在降温过程中通过内源ABA的变化来调控内源保护酶的变化趋势，并协调多种酶的相互作用来抵抗低温。内源ABA、SOD对零上低温敏感，属冷害敏感型调节物质，它们在零上低温前达到最高峰值的时间越早，活性越高，持续的时间越长，马尾松的抗寒性越强；CAT、POD和PPO对零下低温敏感，属冻害敏感型酶类，CAT、POD和PPO的活性越高，持续的时间越长，抗寒性越强。马尾松低温胁迫下4种酶的启动顺序为SOD第1，其次为CAT、POD，最后是PPO。内源ABA能减缓SOD和CAT活性的下降，并能提高POD的活性。抗寒性强的马尾松内源ABA含量和内源保护酶的活性较大，持续时间较长，内源ABA含量和SOD的启动较早，而CAT、POD和PPO的启动时间较迟。马尾松抗寒性的评价是一个多因素相互作用、相互影响的复杂的生理过程，须综合考虑各种酶的活性大小、变化大小、启动和持续时间等多种因素，进行综合评价。

Abstract:

This paper aimed to study endogenic ABA in different provenances and endogenic protective enzymes system dynamic changing laws as well as interaction of them under serial low temperature gradient，with leaves of two superior provenances of Pinus massoniana as materials. The results indicated that P.massoniana controlled the changing of endogenic protective enzyme by changing endogenic ABA during temperature dropping and tuned interaction of multiple enzymes to resist low temperature. Endogenic ABA and SOD were sensitive to supra zero low temperature and were regulatory substance of sensitive to cold injury. If ABA and SOD peaked in less time before supra zero low temperature coming，their activities would be higher，their on going time would be longer and cold resistance of P.massoniana would be stronger. CAT，POD and PPO were sensitive to subzero low temperature and were enzymes of sensitive to freezing injury. The activities of CAT，POD and PPO were higher and persistence time was longer，the stronger cold resistance would be. Under stress of low temperature，the priming sequence of the four enzymes of P.massoniana followed as SOD，CAT，POD and PPO from strong to week. Endogenic ABA could decrease descend of activities of SOD and CAT and also could increase activity of POD. P.massoniana with cold resistance ability had large number content of endogenic ABA and protective enzyme and their persistence time was long. The priming time of endogenic ABA and SOD was early，yet CAT，POD and PPO primed fairly slow. So evaluation of cold resistance ability for P.massoniana was a complicated physiological process with multiple factors interacting each other. It was important to consider synthetically multiple factors included enzyme active，changing，priming and persisting time and so on among all kinds of enzymes and to evaluate them synthetically.