农杆菌介导的smt1富硒基因转化紫花苜蓿研究

利用遗传转化，将硒富基因转入紫花苜蓿（Medicago sativa）是提高苜蓿富硒能力，解决当前硒不足问题的有效途径之一。本研究以“中苜1号”紫花苜蓿为受体材料，通过农杆菌介导法将来自硒超富集植物二沟黄芪(Astragalus bisulcatus)的硒代半胱氨酸甲基转移酶基因(smt1)转入苜蓿，并以3 mg·L-1潮霉素进行筛选，获得转化植株10株。结果表明，5株均能扩增出与smt1基因大小相符的条带。RT PCR检测结果表明，2株目的基因表达呈阳性，这表明smt1基因已成功转入紫花苜蓿基因组中，且可以在植株中正常表达。

Transformation of alfalfa with smt1gene mediated by agrobacterium

Selenium is an essential micronutrient for normal functions of alfalfa （Medicago sativa）. The scarcity of selenium would depress growth of alfalfa and decrease nutritional values of alfalfa hay, which is one of the key problems of low quantity and quality of alfalfa hay in China. Development of transgenic plants with the selenium tolerant genes is a potential pathway to improve selenium level in alfalfa. The gene smt1 cloned from Astragalus bisulcatus was introduced into alfalfa ‘Zhongmu No. 1’ plants mediated by agrobacterium. 32 transgenic plants were obtained after the screening of 3 mg·L-1 Hygromycin. 18 out of 32 were amplified bands consistent with smt1 gene size by PCR and 2 were positive in the gene expression identified by RT PCR. Results indicated that the smt1 gene had been transformed successfully and expressed normally in alfalfa.