Agricultural Biotechnology Center, Gödöllő, Hungary.
Curr Top Microbiol Immunol. 2013;371:153-81. doi: 10.1007/978-3-642-37765-5_6.
RNA interference (RNAi) is an evolutionarily conserved, sequence-specific gene-inactivation system that plays an essential role in many biological processes, such as genome defense against mobile DNA elements or regulation of factors involved in plant and animal development. In higher plants and invertebrates, it also functions as a powerful antiviral mechanism. To overcome antiviral RNAi, viruses have evolved suppressor proteins which counteract host RNAi-based antiviral processes and target one or more key points in the RNAi machinery. Here, we review recent progress in our understanding of the mechanism and function of antiviral RNAi in plants and on the viral responses through the expression of silencing suppressor proteins. As a counter-attack RNAi may also regulate innate immunity in plants and contribute to a novel layer of defense against pathogen attack. We also discuss emerging evidence that viruses use RNAi to manipulate host gene expression to modify the cellular environment for the benefit of invading viruses.
RNA 干扰（RNAi）是一种进化上保守的、序列特异性的基因沉默系统，在许多生物学过程中发挥着重要作用，如基因组防御移动 DNA 元件或调节植物和动物发育过程中的因子。在高等植物和无脊椎动物中，它也是一种强大的抗病毒机制。为了克服抗病毒 RNAi，病毒已经进化出抑制蛋白，这些抑制蛋白可以对抗宿主基于 RNAi 的抗病毒过程，并针对 RNAi 机制中的一个或多个关键点。在这里，我们回顾了近年来我们对植物中抗病毒 RNAi 的机制和功能的理解的最新进展，以及通过表达沉默抑制蛋白对病毒的反应。作为一种反击，RNAi 也可能调节植物的先天免疫，并有助于为抵御病原体攻击提供新的防御层次。我们还讨论了新出现的证据，表明病毒利用 RNAi 来操纵宿主基因表达，以改变细胞环境，使入侵病毒受益。
