The Ti plasmid increases the efficiency of Agrobacterium tumefaciens as a recipient in virB-mediated conjugal transfer of an IncQ plasmid
The Ti plasmid increases the efficiency of Agrobacterium tumefaciens as a recipient in virB-mediated conjugal transfer of an IncQ plasmid
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DOI：
10.1073/pnas.95.12.7057
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发表时间：
1998-06-09
影响因子：
11.1
通讯作者：
Binns, AN
中科院分区：
文献类型：
--
作者：
Bohne, J;Yim, A;Binns, AN
根癌农杆菌的 T-DNA 转移装置介导将 T-DNA 递送到植物细胞中、将 IncQ 质粒 RSF1010 转移到植物细胞中以及农杆菌之间的 RSF1010 接合转移。我们在本报告中表明，如果受体菌株以及供体菌株携带野生型 Ti 质粒并且能够表达vir基因。对导致这种效率提高的可能机制的研究表明，需要由 Ti 质粒编码的 VirB 蛋白。尽管除了 VirB1 之外，农杆菌菌株充当 RSF1010 供体需要形成假定的 T-DNA 转移装置（VirB1-11、VirD4）的所有蛋白质，但仅表达这些蛋白质的一个子集是受体介导的接合转移增加所必需的。具体来说，VirB5、6、11 和 VirD4 是重要的供体成分，但对于增加受体容量来说是可有可无的。 virB9 中确定的点突变以相同的相对程度影响供体和受体的能力，表明 VirB9 的相似功能在这两种情况下都很重要。
The T-DNA transfer apparatus of Agrobacterium tumefaciens mediates the delivery of the T-DNA into plant cells, the transfer of the IncQ plasmid RSF1010 into plant cells, and the conjugal transfer of RSF1010 between Agrobacteria, We show in this report that the Agrobacterium-to-Agrobacterium conjugal transfer efficiencies of RSF1010 increase dramatically if the recipient strain, as well as the donor strain, carries a wild-type Ti plasmid and is capable of vir gene expression. Investigation of possible mechanisms that could account for this increased efficiency revealed that the VirB proteins encoded by the Ti plasmid were required. Although, with the exception of VirB1, all of the proteins that form the putative T-DNA transfer apparatus (VirB1-11, VirD4) are required for an Agrobacterium strain to serve as an RSF1010 donor, expression of only a subset of these proteins is required for the increase in conjugal transfer mediated by the recipient. Specifically, VirB5, 6, 11, and VirD4 are essential donor components but are dispensable for the increased recipient capacity. Defined point mutations in virB9 affected donor and recipient capacities to the same relative extent, suggesting that similar functions of VirB9 are important in both of these contexts.