棉铃虫3种蜕皮相关基因的RNA干扰效应比较  

Comparison of silencing effect of three ecdysis involved genes in cotton bollworm,Helicoverpa armigera

作　　者：杨静[1] 韩召军[1] 

机构地区：[1]南京农业大学植物保护学院/农作物生物灾害综合治理教育部重点实验室,江苏南京210095

出　　处：《南京农业大学学报》2014年第1期81-86,共6页Journal of Nanjing Agricultural University

基　　金：国家自然科学基金重点项目(30771428)

摘　　要：利用表达dsRNA的细菌液连续喂食棉铃虫,比较热激同源蛋白70基因(Hsc70)、几丁质酶基因(Chi)和蜕皮激素受体基因(EcR)的沉默效应。结果表明:dsHsc70处理后试虫热激同源蛋白70基因的表达量为对照的115%,无显著差异,试虫的生长发育也没有显著变化。但dsChi和dsEcR处理后,棉铃虫几丁质酶和蜕皮激素受体基因的表达量分别下降到对照的37.2%和80.3%,且化蛹成功率也显著降低,分别为对照的53.2%和79.1%。此外,dsChi处理棉铃虫的体质量增长缓慢,幼虫死亡率(49.3%)显著高于对照(11.1%),但发育异常率没有显著变化。而dsEcR处理试虫的发育异常率(14.6%)显著高于对照(2.8%),但体质量增长速率和幼虫死亡率与对照没有显著差异。综合分析表明,在RNA干扰研究中,并不是所有的被干扰基因都会表现出明显的沉默效应。因此,为了获得显著的沉默效应,靶基因的选择至关重要。本研究表明:棉铃虫几丁质酶基因较其他两种基因更适合作为研究RNAi防治害虫的靶基因。With continuous ingestion of bacteria fumigation, dsRNAs targeting at three different genes were compared for their RNAi efficiency on phenotypes of cotton bollworm. It was found that ingestion of bacteria expressing dsHsc70 （ heat shock cognate protein 70） did not inhibit the expression of Hsc70 （ 115 % as compared with the control）. The morphology and development of the treated larvae had no significant difference either as compared with the control. However, when ingesting bacteria expressing dsChi （chitinase） or dsEcR （ecdysone receptor）, the expression of the corresponding target gene was depressed to only 37. 2% and 80. 3% ,respectively,and the successful pupation rates of the treated larvae decreased to 53.2% and 79. 1% of the control. Furthermore,it was found that feeding bacteria expressing dsChi resuhed in higher mortality （49.3 % ） as compared with the control （ 11.1% ） ,but had no obvious effect on the abnormal development of test larvae. To the contrary,feeding bacteria expressing dsEcR enhanced significantly abnormal development（ 14.6% ）as compared with the control（2.8% ） ,but no obvious changes in larva body weight and mortality was observed. Therefore,it is not all dsRNA targeting at any genes that could result in phenotypical RNAi. The target gene was the key element for silencing effect. Our results proved that as target genes for further study on pest control with RNAi, Chi was more suitable than the other two genes.

关 键 词：表达dsRNA细菌液 几丁质酶 蜕皮激素受体 热激同源蛋白70 

分 类 号：S852.659.4[农业科学—基础兽医学]