氟虫脲对东亚飞蝗和中华稻蝗几丁质合成酶基因表达的影响

Effects of flufenoxuron on the expression of chitin synthase gene in Locusta migratoria manilensis(Meyen)(Orthoptera:Acrididae)and Oxya chinensis(Thunberg)(Orthoptera:Oedipodidae)

为了探讨氟虫脲可能的作用靶标及毒性机制,本研究以重要农业害虫东亚飞蝗Locusta migratoria manilensis(Meyen)和中华稻蝗Oxya chinensis(Thunberg)为材料,采用简并引物扩增中华稻蝗几丁质合成酶1基因(OcCHS1)的部分cDNA序列;以氟虫脲浸渍法处理2龄中期中华稻蝗及1,2和3龄东亚飞蝗若虫为处理组,丙酮处理为对照组,使用RT-PCR和实时荧光定量PCR方法分析氟虫脲对蝗虫几丁质合成酶基因mRNA表达的影响。结果获得的OcCHS1部分cDNA序列,其长度为312bp,编码104个氨基酸,GenBank登录号为HM214491,与东亚飞蝗几丁质合成酶1基因(LmCHS1)在氨基酸水平上相似度达95%。RT-PCR结果显示,处理组几丁质合成酶1扩增带均强于对照组。实时荧光定量PCR结果表明:与对照组相比,处理组中华稻蝗2龄中期若虫OcCHS1mRNA表达提高了1.02倍,东亚飞蝗1,2,3龄若虫LmCHS1mRNA表达分别提高了34%,82%和89%,差异显著(P<0.05)。分析基因表达提高的原因是几丁质合成受阻后基因表达水平的一种代偿性增加,由此推测几丁质合成酶可能是氟虫脲作用的靶标之一。

In order to explore the possible target and mechanism of flufenoxuron,important agricultural pests Locusta migratoria manilensis and Oxya chinensis were used as test insects in this study.A partial fragment of chitin synthase 1 cDNA from O.chinesis（OcCHS1）was amplified using a pair of degenerate primers.With the mid-2nd instar nymphs of O.chinesis and the 1st,2nd,3rd instar nymphs of L.migratoria manilensis dipped in flufenoxuron as treatments and acetone treatment as the control,the effects of flufenoxuron on the mRNA expression of chitin synthase genes were analyzed using RT-PCR and real-time quantitative PCR.The partial cDNA fragment of OcCHS1（GenBank accession number：HM214491）was obtained,which consists of 312 nucleotides that encode 104 amino acid residues.The deduced amino acid sequence of OcCHS1 showed 95% identity with those of LmCHS1.The results of RT-PCR and real-time quantitative PCR analysis showed that the expression of OcCHS1 in the mid-2nd instar nymphs of O.chinesis and LmCHS1 in the 1st,2nd and 3rd instar nymphs of L.migratoria manilensis exposed to flufenoxuron increased 102%,34%,82% and 89%,respectively,compared to the control.Increased expression of CHS1 mRNA may be due to compensation response of the CHS1 gene at the transcriptional level that is caused by the retarded chitin synthesis.It is so inferred that chitin synthase may be one of targets of flufenoxuron.