Genetic transformation and various biotechnological treatments on hairy roots

本研究利用根农杆菌对几种园艺植物进行了转化试验，并将获得的毛状根作为遗传转化和各种生物技术研究的目标。实验结果如下：1.实验结果表明：用根生农杆菌野生型菌株侵染根毛状根，获得的根毛状根已建立起植株再生体系2。利用含有GUS和NPT II基因的瘤胃a.m umefaciens侵染了猪瘟单胞菌的根尖。选择表达GUS活性和卡那霉素抗性的毛状根，从这些毛状根中再生转基因植株。根尖分生组织的有丝分裂同步得到了不同的处理，其中磷饥饿、羟基脲和秋水仙碱3种处理的有丝分裂指数最高，达到30%。从同步的根尖细胞中分离染色体的试验由于染色体在分离过程中断裂和染色体纯化困难而失败。通过调整秋水仙碱处理的时间和浓度，可以成功地从毛状根培养物中再生出四倍体植株。这些结果表明，包括毛状根在内的根培养物是遗传转化和其他生物技术处理的有用材料。

In this study, transformation of several horticultural plants with Agrobacterium rhizogenes was tried and the hairy roots thus obtained were used as the targets for the studies on the genetic transformation and various biotechnological studies. The results obtaiend are as follows :1. Plant regeneration systems have been established from the hairy roots obtained by infection of leaf segments with wild-type strains of Agrobacterium rhizogenes in Nierembergia repens, N.acoparia, Ipomoea trichocarpa, snapdragon and grape vine.2. Root tips of N.scoparia were infected with A.tumefaciens harboring GUS and NPT II genes. Hairy roots expressing GUS activity and resistance to kanamycin were selected and transgenic plants were regenerated from these hairy roots.3. Root tip meristems were subjected with various treatments for mitotic synchronization and the highest mitotic index (30%) was obtained with the combination of 3 treatments including phosphate starvation, hydroxyurea and colchicine treatments.4. Trials for isolating chromosomes from the synchronized root tip cells resulted in failure due to the break down of the chromosomos during the isolation process and difficulty in purification of the chromosomes.5. Tetraploid plants were successfully regenerated from the hairy root cultures after the treatment with colchicine by adjusting the proper time and concentration.6. These results indicate that root cultures including hairy roots are useful materials for genetic transformation and other biotechnological treatments.