Otten L, Gérard J C, De Ruffray P
C.N.R.S. Institute of Plant Molecular Biology, Strasbourg, France.
Plasmid. 1993 Mar;29(2):154-9. doi: 10.1006/plas.1993.1018.
The octopine/cucumopine (o/c) strains of Agrobacterium vitis are divided into limited (LHR) and wide host range (WHR) strains. We present here the first map of a Ti plasmid from a WHR o/c strain, Tm4. pTiTm4 (252 kb) has homology with the octopine Ti plasmid pTiAch5, the nopaline plasmid pTiC58, and the Ri plasmid pRiHRI. Approximately 155 kb of pTiTm4 is homologous with the LHR o/c Ti plasmids pTiAB3 and pTiAg57, the remaining part is pTiTm4-specific. Our data suggest that the evolution of the o/c Ti plasmids was accompanied by large-scale changes in plasmid structure. The origin of replication of pTiTm4 was localized by a functional assay.
葡萄土壤杆菌的章鱼碱/黄瓜碱（o/c）菌株分为有限宿主范围（LHR）菌株和广宿主范围（WHR）菌株。我们在此展示了来自WHR o/c菌株Tm4的Ti质粒的首张图谱。pTiTm4（252 kb）与章鱼碱Ti质粒pTiAch5、胭脂碱质粒pTiC58和发根质粒pRiHRI具有同源性。pTiTm4约155 kb与LHR o/c Ti质粒pTiAB3和pTiAg57同源，其余部分是pTiTm4特有的。我们的数据表明，o/c Ti质粒的进化伴随着质粒结构的大规模变化。通过功能分析确定了pTiTm4的复制起点。
