Interactions between octopine and nopaline plasmids in Agrobacterium tumefaciens
Interactions between octopine and nopaline plasmids in Agrobacterium tumefaciens
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根癌农杆菌中章鱼碱和胭脂碱质粒之间的相互作用
DOI：
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发表时间：
1980
影响因子：
3.2
通讯作者：
R. Schilperoort
中科院分区：
文献类型：
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作者：
P. Hooykaas;H. Dulk;G. Ooms;R. Schilperoort
将章鱼素钛载体转移到已经携带章鱼素钛载体的菌株中的频率与转移到没有受体的钛载体载体上的频率相同(高)，这表明驻留的钛载体对进入的钛载体没有表现出进入排斥。驻留的章鱼碱钛质粒在进入钛质粒后被受体丢失，这表明钛质粒之间存在不亲和性。研究发现，只有携带诺帕林钛质粒的受者很少能建立起章鱼碱钛载体，反之亦然，只有携带章鱼碱钛载体的受者很少能建立起诺帕林钛载体。尽管存在鸦片碱(章鱼碱)钛质粒，但仍建立了传入的章鱼碱(萝卜碱)钛质粒的罕见克隆似乎含有由整个传入钛质粒和整个驻留的钛质粒组成的协整合体。整合事件总是发生在一个在进化中高度保守的、对致癌作用至关重要的质粒区。这些结果表明，章鱼碱和鸦片碱钛质粒不能作为单独的复制子被同一个细胞维持。因此，根据定义，这些质粒属于同一不亲和性组，已命名为Inc.Rh-1。农杆菌非钛、章鱼和鸦片碱质粒被发现属于另一个不相容组。含有两种不同钛质粒的菌株在协整结构中的致瘤特性表明，它们的毒力基因都得到了表达。农杆菌非钛质粒、章鱼碱和萝卜碱不影响钛质粒编码的毒力特性。
Transfer of octopine Ti plasmids to strains already carrying an octopine Ti plasmid was found to occur at the same (high) frequency as transfer to Ti plasmid lacking recipients, showing that resident Ti plasmids do not exhibit entry exclusion towards incoming Ti plasmids. The resident octopine Ti plasmid was lost by the recipient after the entrance of the incoming Ti plasmid, which is indicative of the incompatibility between the Ti plasmids. Octopine Ti plasmids were found to become established only infrequently in recipients with a nopaline Ti plasmid and, vice versa, nopaline Ti plasmids were only rarely established in recipients with an octopine Ti plasmid. Rare clones in which the incoming octopine (nopaline) Ti plasmid had been established despite the presence of a nopaline (octopine) Ti plasmid appeared to harbor cointegrates consisting of the entire incoming Ti plasmid and the entire resident Ti plasmid. The integration event invariably had occurred in a region of the plasmids that is highly conserved in evolution and that is essential for oncogenicity. These results show that octopine and nopaline Ti plasmids cannot be maintained as separate replicons by one and the same cell. Therefore, be definition, these plasmids belong to the same incompatibility group, which has been names inc Rh-1. Agrobacterial non-Ti octopine and nopaline plasmids were found to belong to another incompatibility group. The tumorigenic properties of strains harboring two different Ti plasmids, in a cointegrate structure, were indicative of the virulence genes of both of them being expressed. The agrobacterial non-Ti octopine and nopaline plasmids did not influence the virulence properties encoded by the Ti plasmid.