INRA-UNSA-CNRS, UMR 1064, Interactions Plantes-Microorganismes et Santé Végétale, 400, route des Chappes, BP 167, F-06903 Sophia Antipolis, France.
J Exp Bot. 2009;60(14):4041-50. doi: 10.1093/jxb/erp237. Epub 2009 Jul 22.
Root-knot nematodes (RKNs) are sedentary biotrophic parasites that induce the differentiation of root cells into feeding cells that provide the nematodes with the nutrients necessary for their development. The development of new control methods against RKNs relies greatly on the functional analysis of genes that are crucial for the development of the pathogen or the success of parasitism. In the absence of genetic transformation, RNA interference (RNAi) allows for phenotype analysis of nematode development and nematode establishment in its host after sequence-specific knock-down of the targeted genes. Strategies used to induce RNAi in RKNs are so far restricted to small-scale analyses. In the search for a new RNAi strategy amenable to large-scale screenings the possibility of using RNA viruses to produce the RNAi triggers in plants was tested. Tobacco rattle virus (TRV) was tested as a means to introduce double-stranded RNA (dsRNA) triggers into the feeding cells and to mediate RKN gene silencing. It was demonstrated that virus-inoculated plants can produce dsRNA and siRNA silencing triggers for delivery to the feeding nematodes. Interestingly, the knock-down of the targeted genes was observed in the progeny of the feeding nematodes, suggesting that continuous ingestion of dsRNA triggers could be used for the functional analysis of genes involved in early development. However, the heterogeneity in RNAi efficiency between TRV-inoculated plants appears as a limitation to the use of TRV-mediated silencing for the high-throughput functional analysis of the targeted nematode genes.
根结线虫（RKNs）是固着性生物营养寄生虫，它们诱导根细胞分化为营养细胞，为线虫的发育提供必要的营养物质。开发针对 RKNs 的新控制方法在很大程度上依赖于对发育关键基因或寄生虫成功寄生至关重要的基因的功能分析。在缺乏遗传转化的情况下，RNA 干扰（RNAi）允许对线虫发育的表型分析以及在宿主中对线虫建立的分析，这是通过靶向基因的序列特异性敲低实现的。迄今为止，用于在 RKNs 中诱导 RNAi 的策略仅限于小规模分析。在寻找一种新的适用于大规模筛选的 RNAi 策略时，研究人员测试了利用 RNA 病毒在植物中产生 RNAi 触发物的可能性。烟草脆裂病毒（TRV）被测试为一种将双链 RNA（dsRNA）触发物引入营养细胞并介导 RKN 基因沉默的方法。研究表明，感染病毒的植物可以产生 dsRNA 和 siRNA 沉默触发物，以递送到取食线虫。有趣的是，在取食线虫的后代中观察到了靶向基因的敲低，这表明连续摄入 dsRNA 触发物可用于参与早期发育的基因的功能分析。然而，TRV 接种植物之间 RNAi 效率的异质性似乎限制了 TRV 介导的沉默在靶向线虫基因的高通量功能分析中的应用。
