Abstract: [Objective] Corythucha ciliata (Say) is an important invasive forest pest, and seriously damages Platanus spp. This paper analyzes the sequence and expression characteristics of chemosensory proteins 1 (CcilCSP1), focus on the ability of CcilCSP1 binding to host volatiles of P. acerifolia. This study gims to provide a foundation for studying function of the chemosensory protein and a useful reference for searching the pheromone substance.[Method] The full-length ORF sequence of CcilCSP1 was obtained by the molecular cloning technique. The expression pattern of CciCSP1 was analyzed by RT-qPCR. The three-dimensional structure of chemosensory protein CcilCSP1 was mimicked, and nine plant volatiles were docked to the CcilCSP1 by AutoDock 4.2. The molecular dynamics simulation analysis was carried out to the docking complex of trans-β-caryophyllene and CcilCSP1. The effects of trans-β-caryophyllene on the C. ciliata were assayed by Y-tube olfactometer.[Result] The CcilCSP1 gene of C. ciliata was cloned and sequenced, and it was highly expressed in adults. The sequence analyses showed that CcilCSP1 had the typical characteristics of CSPs, and closely related with AlucCSP1, AlucCSP3, AlucCSP8 and AlinCSP1. The binding capacity of trans-β-caryophyllene to CcilCSP1 was strongest (k_l=2.63 μm, Binding Energy=-7.61) in nine volatiles. It is suggested that TYR-29, GLN-83, LEU-64 and ASP-30 may be ligand-binding active sites. Molecular dynamics simulations showed that CcilCSP1 protein could bind to trans-β-caryophyllene stably. Furthermore, behavioral experiments showed that 0.1 μg trans-β-caryophyllene had a significant evading effect on the adults of C. ciliata.[Conclusion] CcilCSP1, a chemosensory protein gene highly expressed in C. ciliata adults, was cloned and sequenced in this study. Molecular docking and molecular dynamics simulations were used to investigate the interaction between CcilCSP1 and trans-β-caryophyllene, which was confirmed by the behavioral experiment. This study lays a foundation for the functional study of the protein CcilCSP1 of C. ciliata, and provid a useful reference for searching for the pheromone substance.

Key words: Corythucha ciliata, chemosensory proteins(CSPs), homology modeling, host-plant volatiles, molecular docking, dynamics simulation