title: Midgut-based resistance to oral infection by a nucleopolyhedrovirus in the laboratory-selected strain of the smaller tea tortrix, Adoxophyes honmai (Lepidoptera: Tortricidae).
abstract: A strain of Adoxophyes honmai resistant to Adoxophyes honmai nucleopolyhedrovirus (AdhoNPV) was established from a field-collected colony by repeated selection. Fifth-instar larvae of this resistant strain (R-strain) had over 66 666-fold greater resistance in terms of 50 % lethal concentration values to oral infection of AdhoNPV than non-selected strain larvae (susceptible for AdhoNPV; S2-strain). In this study, the mechanism of resistance to AdhoNPV was determined in R-strain larvae. An assessment of viral genome replication in AdhoNPV-infected S2- and R-strain larvae by quantitative PCR showed no viral genome replication occurring in R-strain larvae. Transcription of AdhoNPV ie-1, vp39 and polyhedrin genes was also not detected in R-strain midgut cells. Besides, a fluorescent brightener had no effect on AdhoNPV infection in either S2- or R-strain. However, binding and fusion of occlusion-derived virus with R-strain were significantly lower than those of S2-strain. These findings suggest that R-strain Adoxophyeshonmai larvae possess a midgut-based resistance to oral infection by AdhoNPV in which midgut epithelial cells are infected less efficiently.
authors.affiliation: Graduate school of Agriculture, Tokyo University of Agriculture and Technology, Saiwai, Fuchu, Tokyo 183-8509, Japan.
authors.forename: Kento
authors.initials: K
authors.lastname: Iwata
authors.affiliation: Alameda County Mosquito Abatement District, 23187 Connecticut Street, Hayward, CA 94545, USA.|Graduate school of Agriculture, Tokyo University of Agriculture and Technology, Saiwai, Fuchu, Tokyo 183-8509, Japan.
authors.forename: Eric
authors.initials: E
authors.lastname: Haas-Stapleton
authors.affiliation: Graduate school of Agriculture, Tokyo University of Agriculture and Technology, Saiwai, Fuchu, Tokyo 183-8509, Japan.
authors.forename: Yasuhisa
authors.initials: Y
authors.lastname: Kunimi
authors.affiliation: Graduate school of Agriculture, Tokyo University of Agriculture and Technology, Saiwai, Fuchu, Tokyo 183-8509, Japan.
authors.forename: Maki N
authors.initials: MN
authors.lastname: Inoue
authors.affiliation: Graduate school of Agriculture, Tokyo University of Agriculture and Technology, Saiwai, Fuchu, Tokyo 183-8509, Japan.
authors.forename: Madoka
authors.initials: M
authors.lastname: Nakai
mesh_terms: D000818:Animals; D028241:Camellia sinensis / Q000469:parasitology; D004064:Digestive System / Q000166:cytology / Q000821:virology*; D004847:Epithelial Cells / Q000821:virology; D016679:Genome, Viral; D007915:Lepidoptera / Q000821:virology*; D017924:Nucleopolyhedroviruses / Q000235:genetics / Q000502:physiology*; D014158:Transcription, Genetic; D014779:Virus Replication