Generation of double-virus-resistant marker-free transgenic potato plants  

作　　者：Yunfeng Bai, Zhihua Guo, Xiaoqi Wang, Dongmei Bai, Weifeng Zhang Institute of Crop Genetics, Shanxi Academy of Agricultural Sciences, Nongke Beilu No. 16, Taiyuan 030031, China 

出　　处：《Progress in Natural Science:Materials International》2009年第5期543-548,共6页自然科学进展·国际材料（英文版）

基　　金：supported by the National Natural Science Foundation of China (Grant No.30471102);International Sci-tech Cooperation Foundation of Shanxi Province (2007081002);Scholarship Foundation of Shanxi Province (200689);the Key Sci-tech Program(20080311016-2) of Shanxi Province,China

摘　　要：Viruses are very widespread in nature, and they cause severe diseases and yield losses in potato production. The transfer of the dsRNA-producing gene could confer a high level virus resistance by specific targeting of cognate viral RNA. In this study, we constructed a marker-free expression vector of a chimeric gene derived from the coat protein sequence of Potato virus X (PVX) and the nuclear inclusion protein sequence of Potato virus Y (PVY) in the form of an intramolecular dsRNA. Then this chimeric gene was introduced into potato cv. Zihuabai, a popular variety in China, via Agrobacterium tumefaciens-mediated transformation. Marker gene-free transgenic plants resistant to both PVX and PVY were obtained and confirmed by RT-PCR and DAS-ELISA detection. Northern blot analysis showed that transgene-derived mRNA was cleaved into short interfering RNAs (siRNAs), and that the virus resistance was mediated by RNA silencing. One important aspect of the study is that the transgenic viral sequence is not translated and the actual RNA transcript is cleaved, which possibly limit the environmental risks, such as transcapsidation and recombination of the transgene with an incoming virus. In addition, the biosafety risk resulting from marker genes can be avoided because of the absence of marker genes in transgenic plants.Viruses are very widespread in nature, and they cause severe diseases and yield losses in potato production. The transfer of the dsRNA-producing gene could confer a high level virus resistance by specific targeting of cognate viral RNA. In this study, we constructed a marker-free expression vector of a chimeric gene derived from the coat protein sequence of Potato virus X （PVX） and the nuclear inclusion protein sequence of Potato virus Y （PVY） in the form of an intramolecular dsRNA. Then this chimeric gene was introduced into potato cv. Zihuabai, a popular variety in China, via Agrobacterium tumefaciens-mediated transformation. Marker gene-free transgenic plants resistant to both PVX and PVY were obtained and confirmed by RT-PCR and DAS-ELISA detection. Northern blot analysis showed that transgene-derived mRNA was cleaved into short interfering RNAs （siRNAs）, and that the virus resistance was mediated by RNA silencing. One important aspect of the study is that the transgenic viral sequence is not translated and the actual RNA transcript is cleaved, which possibly limit the environmental risks, such as transcapsidation and recombination of the transgene with an incoming virus. In addition, the biosafety risk resulting from marker genes can be avoided because of the absence of marker genes in transgenic plants.

关 键 词：Solanum tuberosum MARKER-FREE RNA silencing Double-virus resistance TRANSGENE 

分 类 号：S641.2[农业科学—蔬菜学]