Centre for Plant Sciences, University of Leeds, Leeds LS2 9JT, UK.
Int J Parasitol. 2010 Jun;40(7):855-64. doi: 10.1016/j.ijpara.2010.01.003. Epub 2010 Jan 25.
Ectopically expressed double-stranded RNAs (dsRNAs) have recently been shown to suppress parasitic success of Meloidogyne spp. in plants. We have targeted two genes from the root-knot nematode Meloidogyne incognita; a dual oxidase gene implicated in the tyrosine cross-linking of the developing cuticle and a subunit of signal peptidase, a protein complex required for the processing of secreted proteins. While these genes are involved in different aspects of nematode development, the phenotypic consequences of RNA interference (RNAi) were similar with >or=50% reduction in nematode numbers in the roots and retardation of development to the egg-producing saccate females. Expression of processed dsRNA was observed, but no evidence of detectable levels of small interfering RNAs (siRNAs) was found in the transgenic plants. We show, to our knowledge for the first time, that combining expression of these dsRNAs by crossing appropriate Arabidopsis thaliana lines resulted in an additive effect that further reduced nematode numbers and developmental capacity. Combining RNAi target genes has the potential to enhance the efficacy of RNAi and may allow control of different nematode species or genera in the crop of interest.
异位表达的双链 RNA（dsRNAs）最近被证明可以抑制植物中根结线虫属（Meloidogyne spp.）的寄生成功。我们针对根结线虫（Meloidogyne incognita）的两个基因进行了靶向研究；一个是双氧化酶基因，该基因参与发育中的角质层的酪氨酸交联，另一个是信号肽酶的亚基，该酶是分泌蛋白加工所必需的蛋白复合物。虽然这些基因参与线虫发育的不同方面，但 RNA 干扰（RNAi）的表型后果相似，即在根中线虫数量减少了>或=50%，并延迟了发育到产卵的囊状雌性。观察到了加工 dsRNA 的表达，但在转基因植物中未发现可检测水平的小干扰 RNA（siRNA）。据我们所知，我们首次表明，通过杂交适当的拟南芥（Arabidopsis thaliana）系表达这些 dsRNAs 会产生累加效应，进一步减少线虫数量和发育能力。结合 RNAi 靶基因有可能增强 RNAi 的功效，并可能允许控制感兴趣作物中的不同线虫物种或属。
