A plasmid sequence from Rhizobium leguminosarum 300 contains homology to sequences near the octopine TL-DNA right border

Summary The DNA sequence from a Rhizobium leguminosarum 300 (RL300) plasmid that contains homology to the T_c-DNA of Agrobacterium tumefaciens is described. The RL300 sequence has 78% homology to a 359 bp sequence in the T_c-DNA of pTi15955. The RL300 homology starts approximately 100 bp from the 24 bp border sequence of the T_L-DNA and ends approximately 3 bp from an IS66 homolog in the T_c-DNA. An unusual feature of the RL300 homology is the presence of 81 bp direct repeats with T_c-DNA homology, separated by 201 bp. One end of each direct repeat has a 12 bp palindrome. Four cloned sequences of RL300 with homology to the T DNA region were hybridized to plasmid lysates of RL300 derivatives to determine the source of each plasmid. The sequenced homolog, originally on pRH228, was isolated from pRL7JI; the other 3 homologs were isolated from the transmissable plasmids pRL7JI (pRH235) and pRL8JI (pRH235 and pRH236).     

根癌农杆菌介导的外源基因转化植物萌动种胚的研究

本文建立的新型根癌农杆菌转化程序是以微伤处理的黄瓜、番茄受体态种胚为实验材料,探讨了萌动种胚作为农杆菌TiT-DNA转化受体的可能性;确定了转化体系中筛选条件及受体态种胚的形态学特征和生理学指标;短期内获得了转基因植株,并从生理生化及分子水平上证实了外源基因的转移、整合与表达。本文为农杆菌Ti质粒载体介导的外源基因向植物中的转移提供了一个简便易行的受体系统。     

根癌农杆菌介导的木霉遗传转化及应用进展

木霉作为土传植物病原菌的生防真菌,研究其功能基因具有重要的意义。根癌农杆菌介导的遗传转化(ATMT)为木霉功能基因的研究提供了一个强有力的工具。对根癌农杆菌介导木霉遗传转化的机理、特点、方法及其在木霉中的应用进行了综述。