Identification of arylphorin in Diaphorina citri and determination of its role in response to Bt-bioinsecticidal proteins

Asian citrus psyllid, Diaphorina citri, is the vector of citrus greening disease, also known as Huanglongbing (HLB). HLB is caused by the phloem-restricted bacterium ‘Candidatus Liberibacter asiaticus’ and has been caused huge damage to the citrus industry. Currently management of HLB rely on vector control using insecticides, but long-term use of insecticide develops the resistance in D. citri. Bt-bioinsecticidal proteins would be a good alternative to the classical insecticides. Thus, the identification of insect genes involved in resistance to Bt-bioinsecticidal proteins such as Arylphorin is of great importance. Arylphorin plays an important role in the repair of the gut epithelium following Bt pesticidal protein-induced damage. In current study we identified and in silico analyzed Arylphorin gene in D. citri. Our search did not find any homology in the NCBI database with D. citri genomes. However, the protein sequence of the target gene, Arylphorin from Helicoverpa armigera (well-studied) was blasted with its homologous proteins from D. citri using the Protein–Protein BLAST in the database the “Diaphorina citri OGS v2.0 CDS”. Additionally, we silenced the Arylphorin gene in D. citri nymphs using RNA interference. Currently we are testing the effect of silencing Arylphorin on the mortality of nymphs in combination with Bt-proteins. We hypothesize that the combination with Bt-proteins application with silencing of Arylphorin will maximize the mortality of D. citri.