沉默AiPRMT1基因降低小地老虎对辛硫磷和氯虫苯甲酰胺的耐受性OA

Protein arginine methyltransferase(PRMT)plays crucial roles in insect growth,development,repro-duction,and circadian rhythm regulation.However,the role of PRMT in insecticide tolerance remains poorly understood.In this study,a PRMT gene(designated AiPRMT1)was identified from the black cutworm(Agrotis ipsilon),an important agricultural pest.The sequence characteristics of AiPRMT1 were analyzed via bioinformatic tools.The transcriptional pattern of AiPRMT1 was examined through real time fluorogenic quantitative PCR.AiPRMT1 was silenced via RNA interference technology,and the tolerance of A.ipsilon larvae to three insecticides(phoxim,lambda-cyhalothrin,and chlorantraniliprole)was assessed.The results showed that AiPRMT1 consisted of eight exons and seven introns,and the length of the open reading frame was 1 071 bp.The protein encoded by AiPRMT1 displayed typical characteristics of PRMT.Phylogenetic analysis revealed that AiPRMT1 was most closely related to HaPRMT1 from Helicoverpa armigera and SlPRMT1 from Spodoptera litura.Expression profiling analysis indicated that AiPRMT1 had the highest transcription level in the larval fat body,and the transcription level was higher in the second-to third-instar larval stages than in other developmental stages.The transcriptional levels of AiPRMT1 were obviously upregulated after treatment with phoxim,lambda-cyhalothrin,or chlorantraniliprole.Silencing of AiPRMT1 markedly enhanced larval sensitivity to phoxim and chlorantraniliprole,with mortality rates increasing by 7%and 28%(P＜0.05),respectively,compared with the control group.In contrast,tolerance to lambda-cyhalothrin was not significantly altered.These findings provide a theoretical foundation for further exploration of the molecular mechanisms underlying insecticide tolerance regulated by AiPRMT1.