Project description:The strictly monophagous olive fruit fly, Bactrocera oleae, represents the major pest of olive orchards worldwide. It has the unique ability to hydrolyze olive proteins as well as to overcome olive defenses, especially the high levels of phenolic compounds present in the green olive mesocarp. In this study, we aimed to identify specific genes potentially implicated in overcoming green olive defense and the utilization of the flesh, by examining larval responses to green olives on the transcript level. Focusing on the up-regulated gene set, we identified two putative serine proteases and one putative UDP-glycosyltransferase possibly associated with these traits. Serine proteases could be involved in the digestion of dietary proteins but also could represent a mechanism to overcome the effect of trypsin inhibitors induced by the olive fruit upon attack. UDP-glycosyltransferase may be implicated in the sequestration and/ or direct detoxification of phenolic compounds highly present in green olives.
Project description:Α reduction of pyrethroid efficacy has been recently recorded in the olive fruit fly Bactrocera oleae, the most destructive insect pest of olives worldwide. We analyzed the transcriptomic differences between two highly pyrethroid resistant populations versus a relatively susceptible field population and two laboratory strains to gain more insight into the molecular mechanism of resistance. A large number of genes was found to be significantly differentially transcribed across the pairwise comparisons between resistant and susceptible insect populations. Interestingly, gene set analysis revealed that genes of the ‘electron carrier activity’ GO group were enriched in one specific pairwise transcriptomic comparison. As P450 monooxygenase enzymes are typically associated with this Molecular Function GO-group, this might reflect a P450-mediated resistance mechanism. These results suggest that transcriptional induction of the CYP6 P450s might be an important mechanism of pyrethroid resistance in B. oleae and pave the way for the development of synergists and molecular diagnostics for insecticide resistance management.
Project description:Comparative profiling of damaged (pool of different stages of fly attack) and control undamaged fruits of cv Ortice and cv Ruveia (Olea europaea L.), characterized by a different tolerance to Bactrocera oleae, generated a comprehensive repertory of transcripts useful to study the genes modulated by Bactrocera oleae attack.
