Induction, suppression and requirement of RNA silencing pathways in virulent Agrobacterium tumefaciens infections
Induction, suppression and requirement of RNA silencing pathways in virulent Agrobacterium tumefaciens infections
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DOI：
10.1038/ng1722
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发表时间：
2006-02-01
期刊：
影响因子：
30.8
通讯作者：
Voinnet, O
中科院分区：
文献类型：
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作者：
Dunoyer, P;Himber, C;Voinnet, O
通过 microRNA (miRNA) 调节基因表达和通过小干扰 RNA (siRNA) 进行抗病毒防御是 RNA 沉默的两个方面(1)，这一过程最初被发现是解除武装的根癌农杆菌菌株 (2) 进行植物转化的意外结果。尽管 RNA 沉默可以保护细胞免受外来遗传元件的侵害 (3)，但其针对有毒的、诱发肿瘤的细菌的防御作用仍未得到探索。在这里，我们表明，与转移的DNA癌基因相对应的siRNA最初在有毒的根癌农杆菌感染的组织中积累，并且RNA干扰缺陷的植物对病原体高度敏感。成功的感染依赖于肿瘤中建立的有效的抗沉默状态，从而特异性抑制 siRNA 的合成。这种抑制对 miRNA 通路只有轻微的副作用，这里表明这对疾病的发展至关重要。讨论了根癌农杆菌 RNA 沉默相互作用的相似性和特殊性，并与植物病毒遇到的情况进行了对比。
Regulation of gene expression through microRNAs ( miRNAs) and antiviral defense through small interfering RNAs (siRNAs) are aspects of RNA silencing(1), a process originally discovered as an unintended consequence of plant transformation by disarmed Agrobacterium tumefaciens strains(2). Although RNA silencing protects cells against foreign genetic elements(3), its defensive role against virulent, tumor-inducing bacteria has remained unexplored. Here, we show that siRNAs corresponding to transferred-DNA oncogenes initially accumulate in virulent A. tumefaciens - infected tissues and that RNA interference - deficient plants are hypersusceptible to the pathogen. Successful infection relies on a potent antisilencing state established in tumors whereby siRNA synthesis is specifically inhibited. This inhibition has only modest side effects on the miRNA pathway, shown here to be essential for disease development. The similarities and specificities of the A. tumefaciens RNA silencing interaction are discussed and contrasted with the situation encountered with plant viruses.