Istituto di Virologia Vegetale del CNR, 10135, Torino, Italy.
Mol Plant Pathol. 2013 Jan;14(1):30-43. doi: 10.1111/j.1364-3703.2012.00828.x. Epub 2012 Sep 4.
In plants, RNA silencing is a surveillance mechanism against invading viruses. It involves the production of virus-derived small interfering RNAs (vsiRNAs), which guide the RNA-induced silencing complex (RISC) to inactivate viruses. vsiRNAs may also promote the silencing of host mRNAs in a sequence-specific manner. In this work, vsiRNAs derived from two grapevine-infecting viruses (Grapevine fleck virus and Grapevine rupestris stem pitting-associated virus) were selected from cDNA libraries of short RNAs and were cross-referenced with the remnants of both cleaved host transcripts and viral RNAs from a degradome dataset. We identified dozens of host transcripts targeted by vsiRNAs. Among them, several encode putative proteins involved in ribosome biogenesis and in biotic and abiotic stresses. Moreover, we identified vsiRNAs which explain the cleavage sites in viral genomes. A consistent fraction of vsiRNAs did not apparently account for cleavage, suggesting that only a low percentage of vsiRNAs are involved in the antiviral response.
在植物中，RNA 沉默是一种针对入侵病毒的监测机制。它涉及到病毒衍生的小干扰 RNA（vsiRNA）的产生，这些 RNA 指导 RNA 诱导沉默复合物（RISC）使病毒失活。vsiRNA 也可能以序列特异性的方式促进宿主 mRNA 的沉默。在这项工作中，从短 RNA 的 cDNA 文库中选择了两种感染葡萄的病毒（葡萄斑点病毒和葡萄岩榴茎陷点相关病毒）的 vsiRNA，并与降解组数据集中原病毒切割宿主转录本和 RNA 的残留物进行了交叉引用。我们鉴定了数十种被 vsiRNA 靶向的宿主转录本。其中一些编码核糖体生物发生以及生物和非生物胁迫中涉及的假定蛋白。此外，我们鉴定了 vsiRNA，这些 RNA 解释了病毒基因组中的切割位点。相当一部分 vsiRNA 显然没有解释切割，这表明只有一小部分 vsiRNA 参与抗病毒反应。
