【摘要】 为阐明稻纵卷叶螟(Cnaphalocrocis medinalis)对稻纵卷叶螟颗粒体病毒(C.medinalis granulovirus, CnmeGV)的抵抗机制，本研究分析了稻纵卷叶螟转录因子FOXO和铜/锌超氧化物歧化酶(Copper/zinc superoxide dismutase, Cu/Zn SOD)对CnmeGV感染的响应机制。结果表明，稻纵卷叶螟幼虫脂肪体中Cu/Zn SOD表达水平高于血淋巴、中肠和马氏管等组织；CnmeGV感染后6～48 h,稻纵卷叶螟脂肪体中超氧化物歧化酶活性显著增加，FOXO和Cu/Zn SOD基因mRNA表达水平均显著上调，且抗氧化剂N-乙酰半胱氨酸(NAC)能抑制上调水平。FOXO抑制剂AS1842856和SOD抑制剂LCS-1都能显著增强病毒DNA复制水平，提高CnmeGV感染幼虫的死亡率。上述结果说明，FOXO和Cu/Zn SOD基因的激活程度依赖于氧化应激水平，FOXO和Cu/Zn SOD基因在稻纵卷叶螟幼虫的抗病毒防御中起到关键作用。此外，FOXO抑制剂还能显著削弱病毒感染对Cu/Zn SOD转录的诱导水平，且在Cu/Zn SOD基因启动子区鉴定出多个FOXO结合位点，说明FOXO能直接调控Cu/Zn SOD的表达。本研究结果为稻纵卷叶螟防治、昆虫与病毒互作机制研究提供了新方法。更多还原

【Abstract】 To elucidate the resistance mechanism of Cnaphalocrocis medinalis to C. medinalis granulovirus(CnmeGV), this study analyzed the response mechanism of transcription factor FOXO and copper/zinc superoxide dismutase(Cu/Zn SOD) in C. medinalis to viral infection. The results showed that the expression level of Cu/Zn SOD in fat body of C. medinalis larvae was higher than those in hemolymph, midgut and Malpighian tube. At 6-48 h after CnmeGV infection, the activity of superoxide dismutase in the fat body of C. medinalis increased significantly, and the mRNA expression levels of FOXO and Cu/Zn SOD genes were significantly up-regulated, and the antioxidant N-acetylcysteine(NAC) could inhibit the up-regulation. Both FOXO inhibitor AS1842856 and SOD inhibitor LCS-1 could significantly enhance the level of viral DNA replication and increase the mortality of CnmeGV-infected larvae. The above results indicated that the activation of FOXO and Cu/Zn SOD genes depended on the level of oxidative stress, and FOXO and Cu/Zn SOD genes played key roles in the antiviral defense of C. medinalis larvae. In addition, FOXO inhibitors also significantly attenuated the induction level of Cu/Zn SOD transcription by viral infection, and multiple FOXO binding sites were identified in the Cu/Zn SOD promoter region, indicating that FOXO could directly regulate the expression of Cu/Zn SOD. The results of this study provide a new method for the control of C. medinalis and the study of insect-virus interaction mechanism.更多还原