Zhao Qichao, Liu Minghong, Tan Miaomiao, Gao Jianhua, Shen Zhicheng
State Key Laboratory of Rice Biology, Institute of Insect Sciences, Zhejiang University, Hangzhou, China.
College of Life Science, Shanxi Agricultural University, Taigu, China.
PLoS One. 2014 Oct 15;9(10):e110006. doi: 10.1371/journal.pone.0110006. eCollection 2014.
Insect resistance to Bacillus thuringiensis (Bt) crystal protein is a major threat to the long-term use of transgenic Bt crops. Gene stacking is a readily deployable strategy to delay the development of insect resistance while it may also broaden insecticidal spectrum. Here, we report the creation of transgenic rice expressing discrete Cry1Ab and Cry2Ab simultaneously from a single expression cassette using 2A self-cleaving peptides, which are autonomous elements from virus guiding the polycistronic viral gene expression in eukaryotes. The synthetic coding sequences of Cry1Ab and Cry2Ab, linked by the coding sequence of a 2A peptide from either foot and mouth disease virus or porcine teschovirus-1, regardless of order, were all expressed as discrete Cry1Ab and Cry2Ab at high levels in the transgenic rice. Insect bioassays demonstrated that the transgenic plants were highly resistant to lepidopteran pests. This study suggested that 2A peptide can be utilized to express multiple Bt genes at high levels in transgenic crops.
昆虫对苏云金芽孢杆菌（Bt）晶体蛋白产生抗性是转基因Bt作物长期应用面临的主要威胁。基因叠加是一种可迅速应用的策略，既能延缓昆虫抗性的发展，又可能拓宽杀虫谱。在此，我们报道了利用2A自切割肽从单个表达盒同时表达离散的Cry1Ab和Cry2Ab的转基因水稻的创制，2A自切割肽是病毒的自主元件，可引导真核生物中的多顺反子病毒基因表达。Cry1Ab和Cry2Ab的合成编码序列，由来自口蹄疫病毒或猪捷申病毒-1的2A肽的编码序列连接，无论顺序如何，在转基因水稻中均以高水平表达为离散的Cry1Ab和Cry2Ab。昆虫生物测定表明，转基因植株对鳞翅目害虫具有高度抗性。本研究表明，2A肽可用于在转基因作物中高水平表达多个Bt基因。
