Currier T C, Nester E W
J Bacteriol. 1976 Apr;126(1):157-65. doi: 10.1128/jb.126.1.157-165.1976.
Homology between the large plasmids of 15 pathogenic Agrobacterium strains isolated from various parts of the world has been measured and was found to vary over a wide range, from 3 to 100%. Two genetically distinct groups of plasmids can be identified: one closely related to the plasmid of A. tumefaciens A6, an octopine-utilizing strain, and the other closely related to the plasmid of A. tumefaciens C-58, a nopaline-utilizing strain. The plasmids of four Agrobacterium strains do not belong to either group. One of these four strains utilizes octopine, one utilizes nopaline, and two utilize neither. Three strains contained two large plasmids. In one of these strains, the two plasmids were not homologous to one another. Chromosomal homologies for the Agrobacterium strains surveyed also vary over a wide range, but do not correlate with plasmid homologies. Neither do plasmid homologies correlate with any numerical classification scheme. The significance of these plasmid homology studies for crown gall tumorigenesis is considered.
对从世界各地分离出的15株致病性土壤杆菌的大质粒之间的同源性进行了测定，发现其变化范围很广，从3%到100%不等。可以鉴定出两组遗传上不同的质粒：一组与利用章鱼碱的根癌土壤杆菌A6的质粒密切相关，另一组与利用胭脂碱的根癌土壤杆菌C-58的质粒密切相关。四株土壤杆菌的质粒不属于这两组中的任何一组。这四株菌中的一株利用章鱼碱，一株利用胭脂碱，两株都不利用。三株菌含有两个大质粒。在其中一株菌中，这两个质粒彼此不同源。所调查的土壤杆菌菌株的染色体同源性也有很大差异，但与质粒同源性无关。质粒同源性也与任何数值分类方案无关。考虑了这些质粒同源性研究对冠瘿瘤发生的意义。
