Transcriptional responses of Diabrotica virgifera virgifera larvae to benzoxazinoids

Abstract

AbstractDiabrotica virgifera virgifera is a specialist pest of maize. As such, D. v. virgifera may be expected to have adaptations to cope with maize defences, including benzoxazinoids, the major defensive secondary metabolites of Poaceae. Exposure of D. v. virgifera larvae to benzoxazinoids was manipulated by rearing them on benzoxazinoid biosynthesis deficient mutant maize or a related wild‐type maize line. The transcriptional profiles of larvae fed on wild‐type or mutant maize were analysed by second generation sequencing. Nine transcripts were identified as differentially expressed between larvae fed on the two maize lines. Five transcripts were expressed at a higher level in larvae exposed to benzoxazinoids, including putative cytochrome P450 and cathepsin protease genes. These results support the hypothesis of an inducible counter defence to benzoxazinoids in D. v. virgifera, possibly involving cytochrome P450‐mediated detoxification.