The success for genetic transformation of maize (Zea mays L.) is highly related to genotype of target material. A few model varieties can be induced into type Ⅱ callus, which can be easily transformed with high regeneration frequency. However, most of cultivars could be only induced into type Ⅰ callus, which is difficult to be transformed with low regeneration. Thus, studying on the conditions of induction and transformation for type Ⅰ callus will show great importance for improving elite of maize directly with genetic engineering. Bacillus thuringiensis toxin protein (cry1Ac3) gene was successfully delivered into type Ⅰ calli of two elite inbred lines of maize, 340 and E28, via particle bombardment in this work. Fertile transgenic corn plants were obtained through phosphinothricin (PPT) or hygromycin B (HygB) selection, and the results of PCR, Southern blot assay and ELISA showed that foreign genes had been integrated into maize genome and expressed. In the meantime, strong resistance of some transgenic plants to corn borer was showed through bioassay. In addition, the comparison of selective effect between PPT and HygB showed that PPT, as a selective agent, was better than HygB for the growth and regeneration of resistant calli.
转苏云金杆菌毒蛋白基因玉米植株的获得及其抗虫性分析
李慧芬 李旭刚 刘 翔 常团结 肖桂芳 朱 祯*
（中国科学院遗传研究所，北京100101）
摘要: 玉米( Zea mays L.)转化成功与否与基因型密切相关.在转化过程中,除少数模式品种能够形成再生频率较高且易转化的Ⅱ型愈伤组织外,大多数栽培品种往往只能够形成再生频率较低且不易转化的Ⅰ型愈伤组织.因此探索Ⅰ型愈伤组织的诱导及其转化条件,提高转化效率,对直接改良玉米优良自交系具有重要意义.应用基因枪转化技术将苏云金杆菌( Bacillus thuringiensis ) cry1Ac3基因导入玉米优良自交系E28及340的Ⅰ型胚性愈伤组织中,经过膦丝菌素(PPT)或潮霉素(HygB)筛选,获得了再生植株.经PCR检测、Southern blot分析及Bt毒蛋白ELISA检测证实,外源基因已整合到玉米基因组中,并已获得表达.抗虫性分析结果表明,部分转基因玉米植株对玉米螟虫有较强的抗性.还比较了PPT和HygB两种筛选剂的筛选效果,表明PPT筛选的抗性愈伤组织的再生频率要高于HygB筛选的再生频率.
关键词： 玉米；遗传转化；植株再生；抗虫基因
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