Department of Plant Pathology, University of California, Davis, CA, USA.
Pest Manag Sci. 2012 Jul;68(7):995-1002. doi: 10.1002/ps.3253. Epub 2012 Feb 16.
The glassy winged sharpshooter, Homalodisca vitripennis, is an unusually robust and efficient leafhopper vector of Xylella fastidiosa. X. fastidiosa is the causative agent of Pierce's disease, almond scorch, citrus variegated chlorosis and other serious plant diseases. The present study was conducted to establish whether RNA interference (RNAi) was induced in nymphal H. vitripennis that were injected with actin dsRNAs and other dsRNAs.
A dramatic reduction in target H. vitripennis actin mRNAs and the formation of small interfering RNAs (siRNAs), hallmarks of RNAi, were found following the injection of actin dsRNAs. Quantitative reverse transcription PCR indicated an 80% reduction in actin mRNA levels by 5 days post-injection. Western blot analysis showed a dramatic drop in actin protein levels by 3 days post-injection. Biological effects such as incomplete nymphal-adult ecdysis and > 95% mortality were also found following the injection of fifth-instar nymphs with actin dsRNA. Dramatic reductions in target mRNA levels were also found following the injection of other dsRNAs into fifth-instar H. vitripennis.
The findings indicate that RNAi is induced in post-embryonic leafhoppers by dsRNA. The present system can be used to screen potential gene-silencing targets that can be used for reducing the vector competence of H. vitripennis and other leafhoppers.
玻璃翼蝉，Homalodisca vitripennis，是一种不同寻常的强壮且高效的叶蝉媒介，能够传播 Xylella fastidiosa。X. fastidiosa 是皮尔斯氏病、杏仁灼伤、柑橘斑驳黄化病和其他严重植物病害的病原体。本研究旨在确定注射肌动蛋白 dsRNA 和其他 dsRNA 是否会诱导若虫玻璃翼蝉发生 RNA 干扰（RNAi）。
注射肌动蛋白 dsRNA 后，发现目标 H. vitripennis 肌动蛋白 mRNAs 显著减少，并且形成了小干扰 RNA（siRNA），这是 RNAi 的标志。定量反转录 PCR 表明，肌动蛋白 mRNA 水平在注射后 5 天降低了 80%。Western blot 分析表明，肌动蛋白蛋白水平在注射后 3 天急剧下降。此外，注射第五龄若虫肌动蛋白 dsRNA 还会导致不完全的若虫-成虫蜕皮和超过 95%的死亡率等生物学效应。注射其他 dsRNA 也会导致第五龄 H. vitripennis 中目标 mRNA 水平的显著降低。
这些发现表明，dsRNA 可在胚胎后叶蝉中诱导 RNAi。本系统可用于筛选潜在的基因沉默靶标，用于降低玻璃翼蝉和其他叶蝉的媒介能力。
