Study On The Function Of Abamectin Resistance - Related Genes In Plutella

Diamondback moth Plutella xylostella(L.) as a worldwide pest endanger cruciferae plants.Abamectin is a kind of important pesticides for prevention and control diamondback moth, but at present most of plutella xylostella resistant to abamectin threats continue to use this pesticide.Cytochrome P450 play an important role in insecticide resistance.This study abamectin resistance populations was selected in laboratory. CYP340W1 gene cloning and sequence characteristics analysis, tested the CYP340W1 gene expression in sensitive and resistant populations, different organizations expressions and different ages. RNA interference were used to understand the role of CYP340W1 in the resistance to abamectin in DBM.1. The DBM abamectin resistance population selection in laboratoryCabbage leaf feeding P. xylostella treated with abamectin, select resistant populations and resistant populations(ABM- R) compared with sensitive populations(ABM- S) resistance ratio of 114.96 times.2. Clone and characterization of CYP340W1 in P. xylostellaThe full-length c DNA sequence of a CYP340W1 gene from P. xylostella was obtained. It has a 1491 bp open reading frame(ORF), a 299 bp 5’-untranslated region(UTR), and a 139 bp 3’-UTR. The CYP340W1 c DNA encodes a 496-amino acid peptide with a molecular weight of 56.29 k Da and an isoelectric point of 9.54. Containing P450 characteristic structure C helix(Wxxx R), I helix(Gx DTS), K helix(Exx Rxx P), heme binding sites(Fxx Gxxx Cx G).3. CYP340W1 expression in different life stage, different tissues and susceptible, resistant strainsCYP340W1was constantly expressed during the entire life cycle of P. xylostella. Px Pgp1 in adult males were significantly higher than that in other developmental stages, Different tissue expression analysis showed that the head expression is higher, associated with abamectin is nerve agents.In susceptible and resistant strains the gene expression is 4.46 times higher than in resistant populations a significant difference.4. Identify CYP340W1 genes function by RNA interferenceIn order to identify the function of CYP340W1, RNAi was used. Microinjection CYP340W1 gene ds RNA implement gene silence, found that the expression level of CYP340W1 was significantly decreased at 6 h and was lowest at 12 h and recover after 24 h post injection. The sensitivity to abamectin we found that larval mortality experimental group higher than the control group after RNAi.