Functional Inquiry into ATP-Binding Cassette Transporter Genes Contributing to Spirotetramat Resistance in Aphis gossypii Glover

Abstract

ATP-binding cassette (ABC) transporters regulate the efflux of a broad spectrum of substrates to extracellular transporting, which play an important role in the detoxification process in arthropods. Here, we described a comprehensive approach to explore the involvement of ABC transporters in spirotetramat resistance in cotton aphids. In this study, synergism bioassays showed 17.05% and 35.42% increases in the toxicity to spirotetramat with the ABC inhibitor verapamil in adult and 3rd instar nymph aphids of the SR strain, respectively. In a competitive assay based on the microinjection of a fluorescent ABC transporter substrate, verapamil (a general ABC inhibitor) and spirotetramat significantly inhibited the elimination of Texas Red. Based on transcriptome data of midguts of spirotetramat-susceptible (SS) and -resistant (SR) strains, the expression levels of ABCB4, ABCB5, ABCF2, MRP11, and MRP12 were significantly upregulated in the SR strain midgut compared to that of the SS strain. Gene functional analysis based on ectopic expression and RNA interference (RNAi) proved that ABCB4, ABCB5, ABCF2, MRP11, and MRP12 were involved in the tolerance of cotton aphids to spirotetramat. Moreover, the upregulated ABCF2, ABCB4, and ABCB5 in the midgut of the SR strain contributed more to the resistance of spirotetramat in in vitro functional analysis. In summary, these results demonstrate that candidate ABC transporter genes in the midgut tissue were involved in spirotetramat resistance, which will help reveal the relationship between ABC transporters and the development of spirotetramat resistance in field populations.

Inducible Gut-Specific Carboxylesterase SlCOE030 in Polyphagous Pests of Spodoptera litura Conferring Tolerance between Nicotine and Cyantraniliprole

“…Cyantraniliprole and nicotine bioassays were carried out according to our previous study via a sucrose feeding method. , Briefly, sixteen 2-day-old virgin flies with a straight wing phenotype were placed on degreasing cotton that was dipped in a sucrose solution (20%) with relative insecticide concentrations. Cyantraniliprole was dissolved and diluted to six concentrations in acetone (0, 0.1, 0.2, 0.4, 0.8, 1.6, and 3.2 mg L –1 for the control flies; 0, 0.2, 0.4, 0.8, 1.6, 3.2, and 6.4 mg L –1 for the Esg > SlCOE030 flies) and nicotine was also diluted to six concentrations (0, 12.5, 25, 50, 100, 200, and 400 mg L –1 for the control flies; 0, 25, 50, 100, 200, 400, and 800 mg L –1 for the Esg > SlCOE030 flies).…”

Inducible Cytochrome P450s in the Fat Body and Malpighian Tubules of the Polyphagous Pests of Spodoptera litura Confer Xenobiotic Tolerance

“…Ten 2 day-old virgin flies with straight wing phenotypes were set as one replicate and transferred to a plastic tube containing an artificial diet for the topical bioassay . In addition, a sucrose feeding method was also used to determine fly tolerance to insecticides according to our previous study . Sixteen 2 day-old virgin flies with a straight wing phenotype were set as one replicate and then placed on degreasing cotton that had been dipped in a sucrose solution (20%) containing six different concentrations of cyantraniliprole (0, 0.1, 0.2, 0.4, 0.8, 1.6, and 3.2 mg L –1 for the UAS-CYPs lines and 0, 0.2, 0.4, 0.8, 1.6, 3.2, and 6.4 mg L –1 for the Act5C > CYPs lines).…”

“…32 In addition, a sucrose feeding method was also used to determine fly tolerance to insecticides according to our previous study. 33 Sixteen 2 day-old virgin flies with a straight wing phenotype were set as one replicate and then placed on degreasing cotton that had been dipped in a sucrose solution (20%) containing six different concentrations of cyantraniliprole (0, 0.1, 0.2, 0.4, 0.8, 1.6, and 3.2 mg L −1 for the UAS-CYPs lines and 0, 0.2, 0.4, 0.8, 1.6, 3.2, and 6.4 mg L −1 for the Act5C > CYPs lines). Mortality was recorded after 72 h, and all Drosophila strains were reared under the same conditions as described in the Insect Rearing, Insecticide Induction, and Tissue Dissection section.…”