Nilaparvata lugens Raw sequence reads. Nilaparvata lugens

The brown planthopper (BPH) Nilaparvata lugens is one of the most destructive insect pests in rice production around Asia, no susceptibility with Cry toxins of Bacillus thuringiensis (Bt) or transgenic rice carring Bt cry genes. In this study, transcriptome-wide analysis on intestine or body of BPH were conducted, following with de novo assembly to obtain putative receptors of pore-forming toxins such as Bt Cry toxins and lectins, including 8 cadherins, 5 aminopeptidase N (APNs), and 6 alkaline phosphatase (ALPs). After sequence verification by RT-PCR reactions, sequence homology and phylogenetic analysis were conducted to identify the divergence of putative receptors in BPH against their homologs from Cry susceptible insects. Multiple analysis of protein characters of putative Cry receptors in BPH indicated at least 1 cadherin, 1 APN and 2 ALPs showed similar functional domains as their homologs which could trigger toxicity of Cry toxins in the midgut of target insect. RT-qPCR was then conducted to verify the expression level of each putative Cry receptors in BPH midgut. This study not only expands BPH transcriptomic resources but also provides preliminary identification of putative Cry receptor genes from BPH which is insusceptibility with Bt toxins.