中文摘要：RNA沉默在植物抵抗病毒入侵中起着重要的作用。缺少RNA沉默成份的植物通常会对病毒入侵表现出增强的敏感性。RNA依赖的RNA聚合酶（RDRs）调控的抗病毒防御在许多植物病毒抵抗中起着关键作用。在RDR6调控的病毒侵染防御中，植物特异性RNA结合蛋白即基因沉默抑制因子3（SGS3）也被发现可抵抗拟南芥中的一些病毒。本研究发现，拟南芥SGS3（NbSGS3）是RNA诱导的转录后基因沉默（S-PTGS）和启动RNA触发的系统沉默所必需的。研究结果表明，NbSGS3 与拟南芥RDR6（NbRDR6）协同对抗双生病毒诱导的内源基因沉默（GIEGS）和双生病毒对拟南芥的侵染，这为双生病毒抗性植物育种提供了有价值的信息。
外文摘要：RNA silencing has an important role in defending against virus infection in plants. Plants with the deficiency of RNA silencing components often show enhanced susceptibility to viral infections. RNA-dependent RNA polymerase (RDRs) mediated-antiviral defense has a pivotal role in resistance to many plant viruses. In RDR6-mediated defense against viral infection, a plant-specific RNA binding protein, Suppressor of Gene Silencing 3 (SGS3), was also found to fight against some viruses in Arabidopsis. In this study, we showed that SGS3 from Nicotiana benthamiana (NbSGS3) is required for sense-RNA induced post-transcriptional gene silencing (S-PTGS) and initiating sense-RNA-triggered systemic silencing. Further, the deficiency of NbSGS3 inhibited geminivirus-induced endogenous gene silencing (GIEGS) and promoted geminivirus infection. During TRV-mediated NbSGS3 or N. benthamiana RDR6 (NbRDR6) silencing process, we found that their expression can be effectively fine-tuned. Plants with the knock-down of both NbSGS3 and NbRDR6 almost totally blocked GIEGS, and were more susceptible to geminivirus infection. These data suggest that NbSGS3 cooperates with NbRDR6 against GIEGS and geminivirus infection in N. benthamiana, which provides valuable information for breeding geminivirus-resistant plants.
外文关键词：RNA silencing；geminivirus；RDR6；SGS3；resistance
作者：Li, Fangfang；Wang, Yaqin；Zhou, Xueping
作者单位：中国农业科学院
期刊名称：VIRUSES-BASEL
期刊影响因子：3.4649
出版年份：2017
出版刊次：9
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