Yong Huang1,2, Hongqin Yin1,2, Zeng Zhu1,2, Xingchuan Jiang1,2, Xiuxia Li1,2, Yongcheng Dong1,2, Chengwang Sheng1,2, Min Liao1,2, Haiqun Cao1,2. 1. Anhui Province Key Laboratory of Integrated Pest Management on Crops, Hefei, China. 2. Key Laboratory of Biology and Sustainable Management of Plant Diseases and Pests of Anhui Higher Education Institutes, School of Plant Protection, Anhui Agricultural University, Hefei, China.
Abstract
BACKGROUND: Mythimna separata is a devastating agricultural pest that has recently developed insecticide resistance. Integument-specific cytochrome P450s were reported to participate in cuticle formation and could be potential targets for pesticide synthesis. RESULTS: The transcriptome of integuments of M. separata larvae was constructed, generating a total of 38 058 unigenes with an average length of 1243 bp. These unigenes are enriched in functional categories such as lipid transport and metabolism, and secondary metabolites biosynthesis, transport and catabolism. Amongst unigenes, cytochrome P450s were identified and 66 unique P450s with complete open reading frames were named. These P450s were divided into 17 families and 32 subfamilies, containing conserved motifs such as helix C, helix I, helix K, and the heme-binding region. RNA-Seq and RT-qPCR analyses showed different expression levels of P450s in integuments of M. separata larvae. Further RT-qPCR analysis of P450s among different tissues showed that five P450s, especially CYP4G199, were specifically highly expressed in integuments. Moreover, knockdown of CYP4G199 disturbed cuticle formation, leading to imperfection in larval cuticle, and prevented pupation of M. separata. CONCLUSION: Transcriptome of larval integuments provided sequence and expression of genes in M. separata. CYP4G199 is specifically highly expressed in larval integuments and is important for cuticle formation in M. separata.
BACKGROUND:Mythimna separata is a devastating agricultural pest that has recently developed insecticide resistance. Integument-specific cytochrome P450s were reported to participate in cuticle formation and could be potential targets for pesticide synthesis. RESULTS: The transcriptome of integuments of M. separata larvae was constructed, generating a total of 38 058 unigenes with an average length of 1243 bp. These unigenes are enriched in functional categories such as lipid transport and metabolism, and secondary metabolites biosynthesis, transport and catabolism. Amongst unigenes, cytochrome P450s were identified and 66 unique P450s with complete open reading frames were named. These P450s were divided into 17 families and 32 subfamilies, containing conserved motifs such as helix C, helix I, helix K, and the heme-binding region. RNA-Seq and RT-qPCR analyses showed different expression levels of P450s in integuments of M. separata larvae. Further RT-qPCR analysis of P450s among different tissues showed that five P450s, especially CYP4G199, were specifically highly expressed in integuments. Moreover, knockdown of CYP4G199 disturbed cuticle formation, leading to imperfection in larval cuticle, and prevented pupation of M. separata. CONCLUSION: Transcriptome of larval integuments provided sequence and expression of genes in M. separata. CYP4G199 is specifically highly expressed in larval integuments and is important for cuticle formation in M. separata.