BdorOBP32 Perceiving β‑Caryophyllene: A Molecular Target for Female Attractant Development in Bactrocera dorsalis

Bactrocera dorsalis is a destructive
agricultural pest that attacks over 600 plant species. β-Caryophyllene
is considered a potential compound for developing novel female attractants
due to its attraction to B. dorsalis females. However, the unknown perception mechanism of β-caryophyllene
has been the bottleneck of this process. Odorant binding proteins
(OBPs) function to bind odorants and transport them to olfactory receptors.
Here, behavioral assays revealed that β-caryophyllene strongly
attracted mated, instead of virgin females. RT-qPCR confirmed BdorOBP32 up-regulation out of five OBPs in mated females compared to virgin females. Microscale thermophoresis
(MST) results showed BdorOBP32 bind β-caryophyllene with relatively
high affinity. Subsequently, CRISPR/Cas9 knockout of BdorOBP32 reduced electroantennograms responses and behavioral preferences
to β-caryophyllene in mutants. Moreover, molecular docking and
behavioral analysis identified a novel female attractant (α-angelica
lactone) targeting BdorOBP32. These findings highlight BdorOBP32 plays
critical roles in β-caryophyllene perception and offer new insights
for developing novel olfactory behavior modulators.