The Agrobacterium Ti Plasmids.
The Agrobacterium Ti Plasmids.
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DOI：
10.1128/microbiolspec.plas-0010-2013
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发表时间：
2014-12
影响因子：
3.7
通讯作者：
Christie PJ
中科院分区：
文献类型：
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作者：
Gordon JE;Christie PJ
农杆菌属是植物上的致病菌，包括根癌农杆菌（Agrobacterium tumefaciens）、A.葡萄属、黄毛菊A.鲁比和A.发根菌都携带巨质粒。相比之下，非致病性菌株要么完全缺乏这些质粒，要么携带突变形式的质粒。通过突变分析和证明Ti质粒导入根瘤菌或叶杆菌属，确定了Ti质粒对毒力的严格要求。将这些非致病性物种转化为肿瘤诱导病原体（2，3）。Ti质粒诱导一种称为冠瘿的疾病，其典型表现为在植物冠部（地下到空中的过渡区）形成未分化的植物肿瘤。A.相反，发根农杆菌会诱导毛状根病，其典型表现为在感染部位形成缠绕的根团（4）。
Agrobacteriumspecies that are pathogenic on plants, includingAgrobacterium tumefaciens,A. vitis, A. rubi, andA. rhizogenes, all carry megaplasmids. By contrast, nonpathogenic strains either lack these plasmids entirely or carry mutant forms of plasmids. A strict requirement of the Ti plasmid for virulence was established through mutational analyses and by a demonstration that the introduction of Ti plasmids intoRhizobiumorPhyllobacteriumspp. converts these nonpathogenic species into tumor‐inducing pathogens (2, 3). Ti plasmids induce a disease called crown gall, which is typified by the formation of undifferentiated plant tumors at the plant crown (the subterranean‐to‐aerial transition zone). The related root‐inducing or Ri megaplasmids carried byA. rhizogenesinstead induce hairy root disease, which is typified by the formation of entangled masses of roots at the infection site (4).