Comparative transcriptome analysis reveals potential gene targets for ovipositional inhibition by diallyl trisulfide against female Sitotroga cerealella

The angoumois grain moth, Sitotroga cerealella Olivier, is a serious stored-grain pest worldwide. In previous studies, we demonstrated that diallyl trisulfide (DATS), one of active substances from garlic essential oil, inhibited oviposition of S. cerealella, but the mechanism for this inhibition remains unclear. We suspected that DATS-regulated gene expression changes in S. cerealella may be a reason for the modulation of fertility and reproductive behaviors of the moth. Comparative transcriptomes of female S. cerealella were built by RNA-sequencing to detect differences between DATS exposure and background air with special lights on the key genes related to the fecundity. A total of 304 differentially expressed genes (DEGs) were detected in female moth after exposure to DATS, of which 120 were up-regulated, and 184 were down-regulated. Sixty-two of these DEGs encoding proteins involved in growth and development of eggs and regulation of hormones and mating behavior were identified, and of these, 49 were annotated as chorion protein. Meanwhile, quantitative real-time PCR verified that DEG data were reliable for further transcriptional analysis. Additionally, the results of ovarian dissection and oviposition activity bioassay suggest that DATS has negative effects on ovarian development and fecundity of S. cerealella. Our comprehensive sequence resource with desirable quality enriched the genomic platform of S. cerealella, and the DEGs that were identified will facilitate understanding of the molecular mechanism of ovipositional inhibition by DATS.