Unraveling the venom constituents of the endoparasitoid Aphidius gifuensis with an emphasis on the discovery of a novel insecticidal peptide.

Background: Venom serves as a pivotal parasitic factor employed by parasitoid wasps to manipulate their hosts, creating a favorable environment for the successful growth of their progeny, and ultimately kill the host. The bioactive molecules within parasitoid venoms exhibit insecticidal activities with promising prospects for agricultural applications. However, knowledge regarding the venom components of parasitoids and the discovery of functional biomolecules from them remains limited.

Results: In this study, 30 venom proteins were identified from the endoparasitoid Aphidius gifuensis through the application of a transcriptomic approach. These proteins were categorized into five groups: hydrolase, molecular chaperone, transferase, other functional protein, and hypothetical protein with unknown function. Particularly noteworthy is the abundant expression of the peptide Vn1 in the venom apparatus of A. gifuensis, indicating its pivotal role in venom activity. Consequently, Vn1 was chosen for further functional analysis, exhibiting insecticidal activity against Tenebrio molitor pupae. Further assessment for revealing its mode of action disclosed that Vn1 impacts genes related to immune response, environmental information processing, metabolism, and response to external stimuli in T. molitor, suggesting its involvement in the intricate parasitoid wasp-host interaction.

Conclusion: The findings of this study significantly contribute to our knowledge of the composition and functionality of A. gifuensis venom, establishing a foundation for further investigation into the biological roles of the identified venom constituents. The insecticidal Vn1 isolated from the venom of this parasitoid represents a valuable resource for the development of innovative biocontrol agents with potential applications in agriculture. © 2024 Society of Chemical Industry.