棉铃虫核型多角体病毒感染对宿主昆虫GST活性及其表达水平的影响
Effect of Helicoverpa armigera nucleopolyhedrovirus infection on GST activity and GST expression on host insect

【目的】研究棉铃虫核型多角体病毒（HearNPV）感染宿主昆虫后对宿主谷胱甘肽S-转移酶（GST）活性与基因表达水平的影响，明确病毒在侵染宿主过程中对宿主昆虫GST的调控作用。【方法】采用50和100 PIB/只2种剂量的HearNPV病毒感染3龄棉铃虫，测定感染后不同时间试虫中肠GST活性与其编码基因的表达水平，对比分析病毒感染与未感染健康试虫的GST活性及其编码基因表达水平的差异。【结果】棉铃虫在HearNPV感染初期，GST活性显著提高，同时GST表达水平显著上调；随着感染时间的推移，GST活性与其编码基因的表达水平均显著下降，表明病毒感染后对宿主昆虫GST活性的影响与其对GST表达水平的调控相关。【结论】HearNPV感染棉铃虫过程中，病毒入侵能够激活宿主GST基因的表达，但病毒的持续感染最终会抑制GST编码基因的表达水平。
【Objective】The effect of Helicoverpa armigera nucleopolyhedrovirus (HearNPV) infection on enzyme activity and gene expression of Glutathione S transferase (GST) of host insect was studied to understand the role of virus in regulating host GST after infection. 【Method】The GST enzyme activity and gene expression of 3 years old H.armigera infected with virus at doses of 50 and 100 PIB per insect were determined at different times.Then the viral infection groups and control group were compared to reveal the differences in enzyme activity and gene expression of GST.【Result】GST activity and its gene expression level were up-regulated significantly at the beginning of HearNPV infection.Over time,both were down-regulated,indicating that effect on GST activity by viral infection was related to its expression level.【Conclusion】The viral invasion to host cell triggered GST expression and increased enzyme activity at the beginning.But GST expression was inhibited by persistent infection over time