Project description:Predatory bugs capture prey by injecting venom from their salivary glands using specialized stylets. Understanding venom function has been impeded by a scarcity of knowledge of their venom composition. We therefore examined the proteinaceous components of the salivary venom of the predatory stink bug Arma chinensis (Hemiptera: Pentatomidae). Using gland extracts and venoms from 5th-instar nymphs or adult females, we performed shotgun proteomics combined with venom gland transcriptomics. We found that the venom of A. chinensis comprised a complex suite of over a hundred individual proteins, including oxidoreductases, transferases, hydrolases, ligases, protease inhibitors, and recognition, transport and binding proteins. Besides the uncharacterized proteins, hydrolases such as venom serine proteases, cathepsins, phospholipase A2, phosphatases, nucleases, alpha-amylases, and chitinases constitute the most abundant protein families. However, salivary proteins shared by and unique to other predatory heteropterans were not detected in A. chinensis venom. Injection of the proteinaceous (> 3 kDa) venom fraction of A. chinensis gland extracts or venom into its prey, the larvae of the Oriental armyworm Mythimna separata (Walker, 1865), revealed insecticidal activity against lepidopterans. Our data expands the knowledge of heteropteran salivary proteins and suggests predatory asopine bugs as a novel source for bioinsecticides.
