Construction of RNAi Vector Which Resist Cucumber Mosaic Virus and Transformation of Tobacco

[Objective] Aimed to construct RNAi vector resistant to cucumber mosaic virus and transferred this vector into tobacco. [Method] RT-PCR method was used to amplify cucumber mosaic virus NS04 and process RNA2 gene sequen of tomato isolates. The analysis results of phylogenetic tree demonstrated that the sequence in RNA2 encoded CMV-2a had 98.0% and 96.5% homology with nucleotide and amino acid of DQ412731 isolate of Zhejiang,China. The replicase fragment in CMV RAN2 gene was taken as target sequence to construct pBi35SCR2 eukaryotic expression vector,then the expression vector was identified. Through agrobacterium-mediated method,the expression vector was transferred into tabacco and PCR method was used to check the transfer. The PCR results demonstrated that the experiment had successfully construct eukaryotic expression vector of pBi35SCR2 and the expression vector was successfully transferred into tabacco. [Conclusion] The obtained transgenic tobacco could be used as challenge test material in following experiment and provided foundation for studying processing tomato resist cucumber mosaic virus.

一种快速构建单靶或双靶基因位点RNAi质粒载体的方法

目的开发一种快速构建RNA干扰(RNAi)质粒载体的方法。方法以pBluescriptⅡ质粒载体为母体,逆向导入人U6和H1启动子序列,仅用两条互补的寡核苷酸链,可快速构建单靶基因位点RNAi质粒载体;利用RNAi表达框两侧的MunⅠ及EcoRⅠ酶切位点,将多个干扰表达框串联,可快速构建多靶基因位点RNAi质粒载体;根据以上原则,构建针对绿色荧光蛋白(GFP)基因和萤火虫荧光素酶(LUC)基因的单靶点及双靶点RNAi质粒载体,以检测其干扰效果。结果构建的RNAi质粒载体可产生较理想的干扰效果,单靶点RNAi载体的干扰效率可达90%,双靶点RNAi载体的干扰效率可达87.5%。结论该方法可快速构建单靶点及双靶点的RNAi质粒载体,可在同一细胞内同时对多个靶基因实施有效的RNA干扰。

RNA干扰的机制及其应用

RNA干扰(RNA interference,RNAi)是真核生物中高度保守的,由小分子干扰RNA(small interfering RNA,si RNA)介导的转录后基因沉默现象,在基因功能的研究中得到了非常广泛的应用,并有望成为小核酸药物在疾病治疗中发挥重要作用。现对近年来RNAi的作用机制、si RNA的产生途径、引起RNAi副作用的原因以及RNAi表达载体的设计这四个方面的国内外研究进展进行了总结,对RNAi与CRISPR技术在应用中的关系进行了探讨,展望了RNAi技术未来的发展。