College of Plant Protection, Northwest Agriculture and Forestry University, Yangling, China.
State Key Laboratory for Quality and Safety of Agro-products, Institute of Plant Virology of Ningbo University, Ningbo, China.
Mol Plant Pathol. 2021 Nov;22(11):1383-1398. doi: 10.1111/mpp.13120. Epub 2021 Aug 17.
The Chinese wheat mosaic virus (CWMV) genome consists of two positive-strand RNAs that are required for CWMV replication and translation. The eukaryotic translation elongation factor (eEF1A) is crucial for the elongation of protein translation in eukaryotes. Here, we show that silencing eEF1A expression in Nicotiana benthamiana plants by performing virus-induced gene silencing can greatly reduce the accumulation of CWMV genomic RNAs, whereas overexpression of eEF1A in plants increases the accumulation of CWMV genomic RNAs. In vivo and in vitro assays showed that eEF1A does not interact with CWMV RNA-dependent RNA polymerase. Electrophoretic mobility shift assays revealed that eEF1A can specifically bind to the 3'-untranslated region (UTR) of CWMV genomic RNAs. By performing mutational analyses, we determined that the conserved region in the 3'-UTR of CWMV genomic RNAs is necessary for CWMV replication and translation, and that the sixth stem-loop (SL-6) in the 3'-UTR of CWMV genomic RNAs plays a key role in CWMV infection. We conclude that eEF1A is an essential host factor for CWMV infection. This finding should help us to develop new strategies for managing CWMV infections in host plants.
中国小麦花叶病毒（CWMV）基因组由两条正链 RNA 组成，它们是 CWMV 复制和翻译所必需的。真核翻译延伸因子（eEF1A）对真核生物中蛋白质翻译的延伸至关重要。在这里，我们通过病毒诱导的基因沉默实验表明，沉默烟草原生质体中 eEF1A 的表达可以大大降低 CWMV 基因组 RNA 的积累，而在植物中超表达 eEF1A 则会增加 CWMV 基因组 RNA 的积累。体内和体外实验表明，eEF1A 不会与 CWMV RNA 依赖性 RNA 聚合酶相互作用。电泳迁移率变动分析显示，eEF1A 可以特异性结合 CWMV 基因组 RNA 的 3'非翻译区（UTR）。通过进行突变分析，我们确定 CWMV 基因组 RNA 的 3'UTR 中的保守区域对于 CWMV 的复制和翻译是必需的，并且 CWMV 基因组 RNA 的 3'UTR 中的第六个茎环（SL-6）在 CWMV 感染中起着关键作用。我们得出结论，eEF1A 是 CWMV 感染的必需宿主因子。这一发现应该有助于我们开发管理宿主植物中 CWMV 感染的新策略。
