Two Antenna-Enriched Odorant Binding Proteins in Dioryctria abietella Tuned to General Odorants and Insecticides

Abstract

The management of forest pests has become a significant challenge, particularly for wood borers, because they spend most of the time in the trunks or cones. The coneworm, Dioryctria abietella, is a representative of cone borers as its larvae feed on the cones of Pinaceae plants. The molecular mechanisms underlying the interactions between this species and host plants or habitats can assist in developing strategies for pest control. In this study, we extended the expression profiles of 32 odorant binding proteins (OBPs) in the reproductive tissues of D. abietella, revealing the detectable transcription of 29 genes. Using two DabiOBPs highly expressed in antennae (DabiOBP5 and DabiOBP14) as targets, six compounds with high affinities (dissociation constants < 13 μM) were identified through a reverse chemical ecology strategy, including insecticides widely used for the control of lepidopteran pests. Of these compounds, a floral volatile β-ionone and a pear-produced ester ethyl-(2E,4Z)-decadienoate may serve as behaviorally active compounds in D. abietella. The strong binding of DabiOBPs to insecticides suggested their involvement in insecticide resistance, reflecting sophisticated detoxification mechanisms of this moth. In the molecular simulations, DabiOBP14 possessed stronger interactions with the six ligands compared to DabiOBP5, in which a few key residues within the binding pockets were involved in the formation of hydrogen bonds. This study provides some valuable reference active compounds for the development of lures or repellents in D. abietella and unravels the putative roles of two antenna-dominant DabiOBPs in the perception of plant-derived odorants and insecticides.

Identification and characterization of uridine diphosphate glycosyltransferases in Dioryctria abietella, with an emphasis on putative roles in olfaction and reproduction

“…This broad repertoire with a high number of UGT genes is most likely attributed to the diversity of the tissues sequenced, as the D. abietella transcriptome was composed Entries marked with # mean that there was no detectable transcription in all tissues tested. Each proportion of reproductive tissues was presented in a previous study (Wu et al 2022) samples of 16 tissues (Wang et al 2021). This hypothesis was further supported by the result of 50 AyunUGTs identified from two transcriptomes of female pheromone glands and 12 adult tissues in Achelura yunnanensis (Li et al 2021;Nuo et al 2021;Xiao et al 2022).…”

Binding Properties of Odorant-Binding Protein 7 to Host Volatiles in Larvae of Spodoptera frugiperda

“…The positive clones were inoculated into Luria–Bertani (LB) medium and cultured at 37 °C until they reached a value of optical density (OD) of 0.8 ± 0.2. The recombinant protein was induced by adding a final concentration of 0.5 mM isopropyl β- d -1-thiogalactopyranoside (IPTG) into LB at 37 °C . The bacterial fluid was enrichened by centrifugation, and the bacterial cells were crushed by ultrasonication.…”

“…For example, DabiOBP17 in Dioryctria abietella had high binding affinity to floral volatile, benzyl benzoate. 30 TrufOBP4 in Tirathaba rufivena had ligand-binding abilities to four host plant volatiles. 31 EoblOBP6 in Ectropis obliqua could bind to tea plant volatiles benzaldehyde.…”

“…The recombinant protein was induced by adding a final concentration of 0.5 mM isopropyl β-D-1-thiogalactopyranoside (IPTG) into LB at 37 °C. 30 The bacterial fluid was enrichened by centrifugation, and the bacterial cells were crushed by ultrasonication. The sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) was used to detect SfruOBP7 protein present in supernatant or inclusion bodies.…”

“…OBP in Lepidoptera has been reported to bind to plant volatile components and to be involved in the olfactory perception. For example, DabiOBP17 in Dioryctria abietella had high binding affinity to floral volatile, benzyl benzoate . TrufOBP4 in Tirathaba rufivena had ligand-binding abilities to four host plant volatiles .…”