Molecular identification and the role of adipokinetic hormone receptor in Helicoverpa armigera (H?bner)

In insects, lipids and trehalose are the primary energy reserves and sources, and their metabolism is controlled by a variety of physiological processes. Adipokinetic hormone receptor (AKHR) has been reported to be involved in glycolipid metabolism and immune response, however, is an uncharted territory in Helicoverpa armigera. In the present study, the full-length cDNA encoding AKHR was isolated from H. armigera. The HaAKHR contains a seven-transmembrane domain, which was a characteristic of G-protein coupled receptors. The expression profile analysis revealed that HaAKHR was highly expressed in fat body of newly emerged female adults and highly expressed in the immature stage. The content of triglyceride (TAG) in fat body increased significantly after silencing of HaAKHR, however, the trehalase activity and the expression of trehalose-6-phosphate synthase (TPS) were decreased in hemolymph. Furthermore, the expression level of HaAKHR was significantly upregulated when infected with different kinds of entomopathogenic microbes. The above results suggested that HaAKHR plays an important role in regulating glycolipid metabolism and immune response in H. armigera, and contribute to understanding the underlying mechanism of host-pathogen interactions in H. armigera.