A P-Glycoprotein Is Linked to Resistance to the Bacillus thuringiensis Cry3Aa Toxin in a Leaf Beetle

Yannick Pauchet (1) , Anne Bretschneider (1) , Sylvie Augustin (2) , David G. Heckel (1)

1 Department of Entomology
2 URZF - Unité de recherche Zoologie Forestière

Chrysomela tremula is a polyvoltine oligophagous leaf beetle responsible for massive attacks on poplar trees. This beetle is an important model for understanding mechanisms of resistance to Bacillus thuringiensis (Bt) insecticidal toxins, because a resistant C. tremula strain has been found that can survive and reproduce on transgenic poplar trees expressing high levels of the Cry3Aa Bt toxin. Resistance to Cry3Aa in this strain is recessive and is controlled by a single autosomal locus. We used a larval midgut transcriptome for C. tremula to search for candidate resistance genes. We discovered a mutation in an ABC protein, member of the B subfamily homologous to P-glycoprotein, which is genetically linked to Cry3Aa resistance in C. tremula. Cultured insect cells heterologously expressing this ABC protein swell and lyse when incubated with Cry3Aa toxin. In light of previous findings in Lepidoptera implicating A subfamily ABC proteins as receptors for Cry2A toxins and C subfamily proteins as receptors for Cry1A and Cry1C toxins, this result suggests that ABC proteins may be targets of insecticidal three-domain Bt toxins in Coleoptera as well.

Mots clés: ABC proteins; Bt Cry3Aa toxin; Chrysomela tremula; leaf beetle; Bt resistance; toxin; chafers

Mots clés: protéine ABCA1; toxine; cry3a; bacillus thuringiensis; chrysomela tremulae; chrysomelidae; coleoptera; résistance aux bacteries; identification de gènes

Domaines: Toxicologie

Yannick Pauchet, Anne Bretschneider, Sylvie Augustin, David G. Heckel. A P-Glycoprotein Is Linked to Resistance to the Bacillus thuringiensis Cry3Aa Toxin in a Leaf Beetle. Toxins, 2016, 8 (12), pp.1-12. ⟨10.3390/toxins8120362⟩. ⟨hal-01605001⟩