title: A proteomic approach to study the mechanism of tolerance to Bt toxins in Ostrinia furnacalis larvae selected for resistance to Cry1Ab.
abstract: A Cry1Ab-resistant population of Asian corn borer (ACB-AbR) exhibiting approximately 100 times greater resistance to activated Cry1Ab than a susceptible population (Ostrinia furnacalis; ACB-BtS), was previously shown to exhibit high levels of cross-resistance to Cry1Ah (131-fold), but no cross-resistance to Cry1Ie. It was suggested that the proposed mechanism of resistance was due to the alteration of specific receptors for Cry toxins in the midgut brush border membrane. In the present study a proteomic-based approach was used to identify proteins from brush border membrane vesicles (isolated from both resistant and susceptible Ostrinia furnacalis larvae) interacting with biotinylated Cry1Ab, Cry1Ah, and Cry1Ie. 2D-Electrophoresis in combination with ligand blots were employed and putative protein identities obtained using MALDI-ToF/ToF mass spectrometry. The V-type proton ATPase catalytic subunit A and heat shock 70 kDa proteins were identified as interacting with the Cry toxins tested in the ACB-AbR and ACB-BtS larvae. The biotinylated Cry toxins showed markedly stronger interactions with proteins in the resistant compared to the susceptible larvae, suggesting an up-regulation of the V-type proton ATPase catalytic subunit A and heat shock 70 kDa proteins in the resistant (ACB-AbR) larvae. Interestingly, Cry1Ie interactions with the V-type proton ATPase catalytic subunit A in the ACB-BtS larvae appeared to be absent.
authors.affiliation: The State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, No. 2 West Yuanmingyuan Road, Beijing, 100193, People's Republic of China.
authors.forename: Lina
authors.initials: L
authors.lastname: Xu
authors.forename: Natalie
authors.initials: N
authors.lastname: Ferry
authors.forename: Zhenying
authors.initials: Z
authors.lastname: Wang
authors.forename: Jie
authors.initials: J
authors.lastname: Zhang
authors.forename: Martin G
authors.initials: MG
authors.lastname: Edwards
authors.forename: Angharad M R
authors.initials: AM
authors.lastname: Gatehouse
authors.forename: Kanglai
authors.initials: K
authors.lastname: He
mesh_terms: D000818:Animals; D001413:Bacillus thuringiensis / Q000472:pathogenicity; D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins / Q000235:genetics / Q000633:toxicity*; D001427:Bacterial Toxins / Q000235:genetics / Q000633:toxicity; D004361:Drug Tolerance / Q000235:genetics*; D004731:Endotoxins / Q000235:genetics / Q000633:toxicity*; D006460:Hemolysin Proteins / Q000235:genetics / Q000633:toxicity*; D007814:Larva / Q000187:drug effects / Q000235:genetics; D007915:Lepidoptera / Q000187:drug effects / Q000235:genetics*; D040901:Proteomics
chemical_list: D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins; D001427:Bacterial Toxins; D004731:Endotoxins; D006460:Hemolysin Proteins; C030956:insecticidal crystal protein, Bacillus Thuringiensis