title: Recombinant Helicoverpa armigera nucleopolyhedrovirus with arthropod-specific neurotoxin gene RjAa17f from Rhopalurus junceus enhances the virulence against the host larvae.
abstract: A recombinant Helicoverpa armigera nucleopolyhedrovirus (HearNPV) expressing the insect-selective neurotoxin (RjAa17f) from Cuban scorpion Rhopalurus junceus was constructed by replacing the UDP-glucosyltransferase gene (egt) using λ-red homologous recombination system. Another egt deleted control HearNPV was constructed in a similar way by inserting egfp gene into the egt locus. One-step viral growth curve and viral DNA replication curve analysis confirmed that the recombination did not affect the viral growth and DNA replication in host cells. There is no discernable difference in occlusion-body morphogenesis between RjAa17f-HearNPV, Egfp-HearNPV and HZ8-HearNPV, which was confirmed by transmission electron microscopy analysis. However, the insecticidal activity of RjAa17f-HearNPV is enhanced against the third instar H. armigera larvae according to the bioassay on virulence comparison. There is a dramatic reduction (56.9%) in median lethal dose (LD50) and also a reduction (13.4%) in median survival time (ST50) for the recombinant RjAa17f-HearNPV compared to the HZ8-HearNPV, but only a 27.5% reduction in LD50and 10.1% reduction in ST50value when Egfp-HearNPV is compared with HZ8-HearNPV. The daily diet consumption analysis showed that the RjAa17f-HearNPV was able to inhibit the infected larvae feeding compared with the egt minus HearNPV. These results demonstrated that this novel recombinant RjAa17f-HearNPV could improve the insecticidal effect against its host insects and RjAa17f could be a considerable candidate for other recombinant baculovirus constructions.
authors.affiliation: State Key Laboratory of Crop Stress Biology for Arid Areas, Yangling, Shaanxi, China.|Key Laboratory of Applied Entomology, Northwest A&F University, Yangling, Shaanxi, China.
authors.forename: Huan
authors.initials: H
authors.lastname: Yu
authors.affiliation: State Key Laboratory of Crop Stress Biology for Arid Areas, Yangling, Shaanxi, China.
authors.forename: Bin
authors.initials: B
authors.lastname: Zhou
authors.affiliation: State Key Laboratory of Crop Stress Biology for Arid Areas, Yangling, Shaanxi, China.
authors.forename: Jiao
authors.initials: J
authors.lastname: Meng
authors.affiliation: State Key Laboratory of Crop Stress Biology for Arid Areas, Yangling, Shaanxi, China.
authors.forename: Jian
authors.initials: J
authors.lastname: Xu
authors.affiliation: State Key Laboratory of Crop Stress Biology for Arid Areas, Yangling, Shaanxi, China.|Key Laboratory of Applied Entomology, Northwest A&F University, Yangling, Shaanxi, China.
authors.forename: Tong-Xian
authors.initials: TX
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Crop Stress Biology for Arid Areas, Yangling, Shaanxi, China.
authors.forename: Dun
authors.initials: D
authors.lastname: Wang
mesh_terms: D000818:Animals; D007814:Larva / Q000821:virology; D046529:Microscopy, Electron, Transmission; D009036:Moths / Q000821:virology*; D009498:Neurotoxins / Q000096:biosynthesis / Q000235:genetics* / Q000494:pharmacology; D017924:Nucleopolyhedroviruses / Q000187:drug effects / Q000235:genetics / Q000472:pathogenicity*; D010572:Pest Control, Biological; D012604:Scorpion Venoms / Q000737:chemistry*; D012605:Scorpions / Q000235:genetics*
chemical_list: D009498:Neurotoxins; D012604:Scorpion Venoms
keywords: HearNPV; RjAa17f; recombinant baculovirus; virulence improvement