Liu Mei, Liang Zhiling, Aranda Miguel A, Hong Ni, Liu Liming, Kang Baoshan, Gu Qinsheng
1Zhengzhou Fruit Research Institute, Chinese Academy of Agricultural Sciences, Zhengzhou, 450009 People's Republic of China.
2Huazhong Agricultural University, Wuhan, 430070 People's Republic of China.
Plant Methods. 2020 Feb 3;16:9. doi: 10.1186/s13007-020-0560-3. eCollection 2020.
Cucurbits produce fruits or vegetables that have great dietary importance and economic significance worldwide. The published genomes of at least 11 cucurbit species are boosting gene mining and novel breeding strategies, however genetic transformation in cucurbits is impractical as a tool for gene function validation due to low transformation efficiency. Virus-induced gene silencing (VIGS) is a potential alternative tool. So far, very few ideal VIGS vectors are available for cucurbits.
Here, we describe a new VIGS vector derived from cucumber green mottle mosaic virus (CGMMV), a monopartite virus that infects cucurbits naturally. We show that the CGMMV vector is competent to induce efficient silencing of the phytoene desaturase () gene in the model plant and in cucurbits, including watermelon, melon, cucumber and bottle gourd. Infection with the CGMMV vector harboring sequences of 69-300 bp in length in the form of sense-oriented or hairpin cDNAs resulted in photobleaching phenotypes in and cucurbits by silencing. Additional results reflect that silencing of the gene could persist for over two months and the silencing effect of CGMMV-based vectors could be passaged.
These results demonstrate that CGMMV vector could serve as a powerful and easy-to-use tool for characterizing gene function, controlling viral pathogens or even performing resistance breeding in cucurbits. Moreover, this study will possess considerable important reference value for developing different viral vectors.
葫芦科植物所结出的果实或蔬菜在全球范围内具有重要的饮食价值和经济意义。已公布的至少11种葫芦科物种的基因组推动了基因挖掘和新型育种策略的发展，然而，由于转化效率低，葫芦科植物中的遗传转化作为基因功能验证的工具并不实用。病毒诱导的基因沉默（VIGS）是一种潜在的替代工具。到目前为止，很少有理想的VIGS载体可用于葫芦科植物。
在此，我们描述了一种源自黄瓜绿斑驳花叶病毒（CGMMV）的新型VIGS载体，CGMMV是一种自然感染葫芦科植物的单分体病毒。我们表明，CGMMV载体能够在模式植物以及包括西瓜、甜瓜、黄瓜和瓠瓜在内的葫芦科植物中高效诱导八氢番茄红素去饱和酶（）基因的沉默。用携带长度为69 - 300 bp的 序列的CGMMV载体以有义方向或发夹cDNA的形式进行感染，通过 沉默在 和葫芦科植物中导致光漂白表型。其他结果表明， 基因的沉默可以持续两个多月，并且基于CGMMV的载体的沉默效果可以传代。
这些结果表明，CGMMV载体可作为一种强大且易于使用的工具，用于在葫芦科植物中鉴定基因功能、控制病毒病原体甚至进行抗性育种。此外，本研究对于开发不同的病毒载体将具有相当重要的参考价值。
