以抗除草剂Bar基因稳定转化谷子技术研究

农杆菌介导的谷子遗传转化效率一直是制约谷子功能基因研究及转基因育种效率的主要因素。本研究以冀谷11谷子幼穗为外植体, 选取0.5~1.0 cm的幼穗, 切成0.5 cm左右的小段, 置改良后的MS培养基上诱导15~20 d形成胚性愈伤组织3120块。愈伤组织侵染转化前用侵染液悬浮浸泡, 并经45°C热激预处理3 min, 可以有效提高26.1%的瞬时遗传转化效率。将转化后的愈伤组织经草丁膦(PPT)筛选后获得513块抗性愈伤组织, 抗性愈伤组织获得率为16.4%。抗性愈伤组织经分化、壮苗培养后获得7株抗性植株, 经PCR和Southern杂交检测得到6株T₀代转基因阳性株, 对T₃代转化植株叶片进行PPT抗性分析, 并结合Bar蛋白抗体试纸条鉴定, 表明Bar基因已稳定整合到谷子基因组中。本研究建立了农杆菌介导转化谷子优良品种的遗传转化体系, 对提高谷子转基因育种效率和谷子模式研究系统的建立有重要意义。

Use of Bar Gene for the Stable Transformation of Herbicide-resistant Foxtail Millet Plants

Efficiency of Agrobacterium-mediated genetic transformation has been the main factor that restricts the study of functional genes and transgenic breeding in foxtail millet. In this study, foxtail millet variety Jigu 11 panicle primordia were used as explants. Young panicles of 0.5-1.0 cm in length were picked and cut into small pieces. The young embryos were cultured in modified MS medium for inducing embryogenic calli, totally forming 3120 embryogenic calli in 15-20 days. Soaking the calli in the infection suspension prior to transformation, and the heat treatment at 45°C for 3 min could effectively improve the transient genetic transformation efficiency by 26.1%. The transformed calli were screened with phosphinothricin (PPT), in which 513 were resistant calli, with the resistant calli rate of 16.4%. Seven herbicide-resistant plants were obtained after resistant calli differentiation and seedling culture. Six T₀ transgenic positive plants were identified by PCR and Southern blot. PPT resistance analysis was carried out on leaves in T₃ generation of transformed plants, and combined with Bar protein antibody test strip identification, the results confirmed that the Bar gene stably incorporated into the genome of foxtail millet seedlings. This study established a stable genetic transformation system in foxtail millet, which is of great significance in improving the efficiency of molecular breeding, and prompting foxtail millet as a new model plants.