Transcriptome Analysis Reveals the Venom Genes of the Ectoparasitoid Habrobracon hebetor (Hymenoptera: Braconidae).

Simple Summary: The ectoparasitoid Habrobracon hebetor (Hymenoptera: Braconidae) exhibits broad parasitic abilities against lepidopteran pests, utilizing its venom as a key factor for host mortality. Analyzing the venom's constituents is crucial to understanding the mechanisms of efficient host killing and identifying functional venom proteins. Transcriptomic analysis identified 34 venom proteins in H. hebetor, including serine protease, metalloproteinase, and esterase, as well as unique proteins like paralytic protein and ion transport peptide-like. Spatial gene expression profiling confirmed high expression of these venom proteins in the venom apparatus, particularly noting the importance of the paralytic protein in successful parasitism. This discovery of venom proteins sets the stage for research on bioactive agents for pest control. The ectoparasitoid Habrobracon hebetor (Hymenoptera: Braconidae) exhibits a broad parasitic capability towards various lepidopteran pests, with venom serving as a crucial virulent factor ensuring successful parasitization and subsequent host mortality. Analyzing the constituents of its venom is essential for elucidating the mechanisms underlying efficient host killing by this parasitoid and for exploring potentially functional venom proteins. Through a transcriptomic analysis, a total of 34 venom proteins were identified within the venom of H. hebetor, encompassing known components such as serine protease, metalloproteinase, esterase, and serine protease inhibitors commonly present in parasitoid venoms. Unique components like paralytic protein and ion transport peptide-like were identified, possibly specific to certain parasitoids, along with novel proteins with uncharacterized functions. Spatial gene expression profiling of the identified venom proteins using transcriptomic data, corroborated by quantitative PCR validation for 13 randomly selected proteins, revealed abundant expression levels in the venom apparatus, affirming them as genuine venom components. Notably, the paralytic protein exhibited prominent expression, with the highest FPKM (fragments per kilobase of transcript per million fragments mapped) value of 24,704.87 in the venom apparatus, indicative of its significant role in successful parasitism by H. hebetor. The identification of these venom proteins establishes a foundation for the further exploration of bioactive agents for pest management strategies. [ABSTRACT FROM AUTHOR]