The Species, Molecular Characteristics, and Detoxification of ABC Transporter Genes in Eriosoma lanigerum.

The ATP-binding cassette (ABC) transporter superfamily is one of the largest groups of membrane proteins, involved in phase III of the detoxification process and plays important roles in insecticide resistance. In this study, A total of 69 ABC transporter proteins genes was identified based on genome and transcriptome, including 18 ABCA genes, 6 ABCB genes, 11 ABCC genes, 5 ABCD genes, 3 ABCF genes, and 26 ABCG genes in Eriosoma lanigerum. Among the 69 ABC transporters, 15 are classified as full transporters, while 27 are identified as half transporters. Within the ABCA and ABCG subfamilies, there are 14 and 5 proteins, respectively, that possess only the NBD domain and lack the TMD domain, indicating that these proteins do not perform transmembrane functions. Two notable ABC transporters have recently been identified in the ABC transporters of E. lanigerum. ElABCC1 features 4 NBDs and 4 TMDs, whereas ElABCG21 comprises 3 NBDs and 3 TMDs. In this study, the ElABCG2 gene was cloned, revealing that its full-length sequence is 2082 bp and that it belongs to the category of half transporters. Temporal and spatial expression analyses indicate that the expression level of this gene significantly increases during the growth of the instar stages. Furthermore, it is expressed in the head, thorax, and abdomen, with expression levels exhibiting an upward trend. The RNAi technique was employed to specifically knock out the ElABCG2 gene. Subsequently, E. lanigerum were exposed to the median lethal concentrations of imidacloprid and thiamethoxam. The results demonstrated that following the knockout of this gene, the sensitivity of E. lanigerum to imidacloprid increased significantly, while no notable change was observed in their sensitivity to thiamethoxam. This suggests that the ElABCG2 gene may play a crucial role in the detoxification process of E. lanigerum against imidacloprid. However, the specific detoxification mechanism warrants further investigation.