同位素示踪技术研究JA在巴西橡胶树中的运输和分布

Transportation and Distribution of Exogenous JA Revealed by Radioisotope Technique in Hevea brasiliensis

为了研究外源茉莉酸(jasmonic acid,JA)在巴西橡胶树中的移动方向、运输途径以及分布规律,以无性系CATAS7-33-97为实验材料,对其幼嫩萌条进行外施3H-JA和3H-JA+机械伤害处理,用同位素示踪技术对外源3H-JA在萌条不同部位的放射性强度进行了研究。结果表明,外施JA在进入植株体内1h后,大部分集中在施用部位;伤害能明显阻止外源JA进入树皮组织,但同时也阻止进入了的JA再向其他部位转移;新梢中积累的JA明显低于施用部位,但比其他4个部位都高。外源JA在巴西橡胶树中可以同时向上和向下运输,运输的途径主要是韧皮部,但木质部也是运输部位之一。由此可见,在巴西橡胶树中,外源JA能够迅速地被运输到周边部位,代谢旺盛的部位具有易富集JA的能力,而机械伤害对JA在植株体内的分布有明显的影响。

In order to research the mobile direction and approach of exogenous JA as well as regularity of distribution in Hevea brasiliensis.The shoots of clone CATAS7-33-97 were used as the experimental material,which had been treated respectively by applying exogenous 3H-JA,mechanical wounding and exogenous 3 H-JA.By using radioisotope technique,the radioactivity in the different sites of shoot was studied.The results showed that the most radioactivity of 3H-JA sustained in the bark of treated site within one hour,and mechanical wounding hindered the entrance of exogenous JA meanwhile held back the entered JA to the around regions.The radioactivity in the sample of extending new shoot was obviously lower than the radioactivity of the treated site bark,but significantly higher than the other four sites.Exogenous JA could be transported upwards and downwards through phloem mainly and xylem secondary.Thus it could be seen that exogenous JA was rapidly transported to the regions around wounded site after entrance,and the vigoroustender site accumulated JA easily.Moreover,mechanical wounding affected obviously the distribution of JA in the shoot.