title: Meloidogyne incognita: molecular and biochemical characterisation of a cathepsin L cysteine proteinase and the effect on parasitism following RNAi.
abstract: RNA interference has been used to investigate the function of a cathepsin L cysteine proteinase Mi-cpl-1, in the plant-parasitic nematode Meloidogyne incognita. A reduction in gene transcript was observed and the number of nematodes infecting plants was reduced by almost 60% as was the number of established females producing eggs at 21 days post-infection. The cysteine proteinase activity of M. incognita, reported by the substrate GLUpNA, was inhibited by the cysteine proteinase inhibitor Oc-IDeltaD86. A reduction in cysteine proteinase activity was also seen following RNAi of Mi-cpl-1 in J2 stage nematodes. In situ hybridization analysis in young and mature female nematodes has shown that Mi-cpl-1 is expressed in the intestine, which suggests that its product is a digestive enzyme. The effects of knocking-out Mi-cpl-1gene function were consistent with a reduction in feeding efficiency. Here, we have shown a correlation between transcript abundance proteinase activity and parasitic success of M. incognita.
authors.affiliation: Centre for Plant Sciences, University of Leeds, Leeds LS2 9JT, UK.
authors.forename: J
authors.initials: J
authors.lastname: Shingles
authors.forename: C J
authors.initials: CJ
authors.lastname: Lilley
authors.forename: H J
authors.initials: HJ
authors.lastname: Atkinson
authors.forename: P E
authors.initials: PE
authors.lastname: Urwin
mesh_terms: D000818:Animals; D056668:Cathepsin L; D002403:Cathepsins / Q000235:genetics* / Q000378:metabolism*; D002863:Chromogenic Compounds / Q000378:metabolism; D003546:Cysteine Endopeptidases / Q000235:genetics* / Q000378:metabolism*; D005260:Female; D015971:Gene Expression Regulation, Enzymologic; D017403:In Situ Hybridization; D018551:Solanum lycopersicum / Q000469:parasitology; D018517:Plant Roots / Q000469:parasitology; D034622:RNA Interference; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014431:Tylenchoidea / Q000201:enzymology* / Q000235:genetics / Q000472:pathogenicity
chemical_list: D002863:Chromogenic Compounds; D002403:Cathepsins; D003546:Cysteine Endopeptidases; D056668:Cathepsin L