The transcription factor PcDfd regulates expression of PcCCE5 involved in spirodiclofen resistance in Panonychus citri ( McGregor )

BACKGROUND Carboxyl/cholinesterases (CCEs) play a vital role in the initial metabolism of endogenous and exogenous substances. In a previous study, an overexpression CCE gene PcCCE5 was found to be involved in the resistance of Panonychus citri to spirodiclofen. However, the underlying regulatory mechanism has rarely been documented. RESULTS In this study, the cis‐acting element of PcCCE5 was identified in the region between −674 and −483 bp. Dual‐luciferase reporter assay demonstrated that co‐transfection of reporter plasmid containing the PcCCE5 promoter with PcDfd expressing constructs significantly improved transcription. Yeast one‐hybrid (Y1H) and electrophoretic mobility shift assay (EMSA) further confirmed the interaction between transcription factor PcDfd and the PcCCE5 promoter. The expression level of PcDfd was significantly up‐regulated in the spirodiclofen‐resistant (DL‐SC) strain and after exposure to spirodiclofen. Silencing of PcDfd significantly decreased the expression of PcCCE5 and increased the susceptibility of the DL‐SC strain to spirodiclofen. CONCLUSION These results indicate that the transcription factor PcDfd up‐regulates the expression of PcCCE5 by binding to the ‘TAATTGTT’ motif, which was involved in spirodiclofen resistance in Panonychus citri . To our knowledge, this is the first report to discover transcription factor PcDfd contributed to acaricide resistance.