title: Knockdown of midgut genes by dsRNA-transgenic plant-mediated RNA interference in the hemipteran insect Nilaparvata lugens.
abstract: BACKGROUND
  RNA interference (RNAi) is a powerful technique for functional genomics research in insects. Transgenic plants producing double-stranded RNA (dsRNA) directed against insect genes have been reported for lepidopteran and coleopteran insects, showing potential for field-level control of insect pests, but this has not been reported for other insect orders.
  
  
  RESULTS
  The Hemipteran insect brown planthopper (Nilaparvata lugens Stål) is a typical phloem sap feeder specific to rice (Oryza sativa L.). To analyze the potential of exploiting RNAi-mediated effects in this insect, we identified genes (Nlsid-1 and Nlaub) encoding proteins that might be involved in the RNAi pathway in N. lugens. Both genes are expressed ubiquitously in nymphs and adult insects. Three genes (the hexose transporter gene NlHT1, the carboxypeptidase gene Nlcar and the trypsin-like serine protease gene Nltry) that are highly expressed in the N. lugens midgut were isolated and used to develop dsRNA constructs for transforming rice. RNA blot analysis showed that the dsRNAs were transcribed and some of them were processed to siRNAs in the transgenic lines. When nymphs were fed on rice plants expressing dsRNA, levels of transcripts of the targeted genes in the midgut were reduced; however, lethal phenotypic effects after dsRNA feeding were not observed.
  
  
  CONCLUSIONS
  Our study shows that genes for the RNAi pathway (Nlsid-1 and Nlaub) are present in N. lugens. When insects were fed on rice plant materials expressing dsRNAs, RNA interference was triggered and the target genes transcript levels were suppressed. The gene knockdown technique described here may prove to be a valuable tool for further investigations in N. lugens. The results demonstrate the potential of dsRNA-mediated RNAi for field-level control of planthoppers, but appropriate target genes must be selected when designing the dsRNA-transgenic plants.
authors.affiliation: State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan, People's Republic of China.
authors.forename: Wenjun
authors.initials: W
authors.lastname: Zha
authors.forename: Xinxin
authors.initials: X
authors.lastname: Peng
authors.forename: Rongzhi
authors.initials: R
authors.lastname: Chen
authors.forename: Bo
authors.initials: B
authors.lastname: Du
authors.forename: Lili
authors.initials: L
authors.lastname: Zhu
authors.forename: Guangcun
authors.initials: G
authors.lastname: He
mesh_terms: D000818:Animals; D041981:Gastrointestinal Tract / Q000378:metabolism*; D006430:Hemiptera / Q000235:genetics*; D019476:Insect Proteins / Q000235:genetics*; D012275:Oryza / Q000235:genetics / Q000378:metabolism*; D030821:Plants, Genetically Modified / Q000235:genetics / Q000378:metabolism*; D034622:RNA Interference / Q000502:physiology*; D012330:RNA, Double-Stranded / Q000235:genetics*
chemical_list: D019476:Insect Proteins; D012330:RNA, Double-Stranded