侧柏幼苗切根后根系内源激素含量的变化

摘要

以侧柏1 a生幼苗为研究对象,采用1/2切根(A),1/3切根(B),1/4切根(C)和不切根(CK)4种处理,应用间接酶联免疫法(ELISA)测定不同切根比例幼苗根系中ABA,GA3,IAA,CTK等4种内源激素的短期变化.结果表明,当植物受到切根伤害后的第1天,侧柏幼苗根系中ABA含量快速升高,切根比例越大,与对照相比上升的幅度越大.随着伤害的结束及根系自身的修复,ABA含量逐渐回落.切根后的第1天(A处理)或前4 d(B和C处理),根系中CTK含量迅速下降,但切根比例越大,与对照的差异越小.这可能是因为根系CTK含量的变化,不仅与合成速率有关,还受向上运输能力的影响.切根伤害后根系IAA含量逐渐下降,但A处理的幼苗根系IAA含量在切根后第1天出现了1个峰值,这在某种程度上减弱了由于ABA含量增加而产生的对侧柏幼苗根系生长的抑制作用.切根对侧柏根系中GA3含量的影响不太显著,只是随着培养时间的延长,其含量逐渐下降,并表现了相似的下降速率.%Contents of ABA, GA3, IAA, CTK in the root of 1/2 (A), 1/3 (B) and 1/4 (C) of main　root-cutting seedling of one-year Platycladus orientalis were measured compared with the intact seedling　(CK). The results showed that the content of ABA incresed quickly one day after the start of the　experiment, and the more cut, the more increased. Then, it gradually decreased, which might be responsible for the restoration of root system. The content of CTK decreased quickly one day ( 1/2 rootcutting) or four days ( 1/3 and 1/4 root-cutting) after the start of the experiment, and then gradually　increased. The more root was cut, the smaller difference was from the control, which is because the　content of CTK in root is affected not only by the synthsis rate, but by the transport capacity to the　shoot. After root-cutting, root IAA content gradually declined. On the other hand, a peak value of root　IAA content emergenced 1 d after cutting, and this might weaken the inhibition to root growth from the　increase of root ABA. The root GA3 content was not affected by root-cutting significantly, but gradually　declined during the subsequent days of the experiment with similar decrcase rates.