【目的】应用RNA干扰技术同时抑制大豆脂肪氧化酶（Lox）和胰蛋白酶抑制剂（KTi）基因的表达,改良大豆品质,培育缺失Lox和KTi的大豆新材料。【方法】应用RNAi原理,以双价RNAi植物表达载体pCAM-BIA1301-KtiRi-LoxRi为基础,以植物表达载体pCAMBIA3301的质粒DNA为模板,利用CaMV35S启动子的上游引物和CaMV35S终止子的下游引物,PCR扩增含有除草剂抗性基因bar的整个表达原件,然后将其插入到pCAM-BIA1301-KtiRi-LoxRi中,构建以除草剂为筛选标记的双价RNAi表达载体,并通过花粉管通道法转化至大豆吉农18、吉农28和吉农27 3个品种中,对转基因植株进行PCR、Southern杂交、RT-PCR分子水平检测和除草剂抗性检测。【结果】质粒PCR和酶切鉴定以及测序结果表明,双价RNAi植物表达载体pCAMBIA1301-KtiRi-LoxRi-bar构建成功。将其转入到大豆中,分别获得吉农18、吉农28、吉农27T1代籽粒47,25和86粒,以及T2代转基因植株50株。RT-PCR结果表明,转基因株系中脂肪氧化酶和胰蛋白酶抑制剂mRNA积累受到明显抑制。【结论】获得了转pCAMBIA1301-KtiRi-LoxRi-bar的T2代转基因大豆。%【Objective】 The objective of this study was to find a new breeding technique of soybean to improve its quality and create new elite germplasm resource of soybean by RNAi,which prohibited the expression of lipoxygenase and kunitz tripsin inhibitor genes in soybean seed.【Method】 In this research,we used plant expression vector pCAMBIA1301-KtiRi-LoxRi as substrate and used pCAMBIA3301 as the template.CaMV35S promoter was upstream primer and CaMV35s terminator was downstream primer.The whole expression objective with herbicide resistance gene was amplified by PCR before being inserted into pCAMBIA1301-KtiRi-LoxRi to construct the RNAi expression vector using herbicide as selection marker.Then the obtained expression vector was transferred to soybean cultivars Jinong 18,Jinong 28 and Jinong 27 by pollen tube pathway Transgenic plants were screened with barstar,and detected by PCR,Southern blot,and RT-PCR.【Result】 We have obtained seed-specific expression vector pCAMBIA1301-KtiRi-LoxRi-bar and put it into soybean.The number of obtained positive transgenic seeds in T1 generation for Jinong 18,Jinong 28,and Jinong 27 were 47,25,and 86,respectively.A total of 50 T2 generation transgenic plants were obtained as well.RT-PCR demonstrated that the mRNA of lipoxygenase in transgenic soybeans was significantly inhibited.In addition,the activities of lipoxygenase and Kti decreased significantly in the progenies of transgenic soybean seeds.【Conclusion】 We have obtained transgenic plant lines of T2 generation.
展开▼
