Transformation Of ZDS And LycB Into Elite Maize Inbred Lines

Carotenoids have VA original activity and play a significant role in antioxidation,enhancing immune function and natural staining agent. Whileδ-carotene dehydrogenase and Lycopeneβ-cyclase play an important part in carotenoid biosynthetic pathway. Therefore, ZDS and LycB can be introduced into maize, the third largest food crops in the world, by Agrobacterium-mediated transformation. And new maize varieties of high-vitamin A can be created by transgenic technology, which is of great significance in improving the nutritional health of people in poor areas, solving the problem of vitamin A deficiency and a better use of maize.In this study, we established the genetic transformation systems of maize through optimizing the regeneration systems of maize and transferring desired genes into elite maize inbred lines using an Agrobacterium-mediated method. And we successfully obtained the positive transgenic plants by resistance screening and molecular detection. Procedures are as follows: First,the high efficient expression vector is identified. Second, we compared the type II callus formations of several genotypes of maize immature embryos, then we adopted N6 and NM callus induction media. The maize inbred line 7922,238,160 and 9543 had adapted to the two medium. In addition, the size of immature embryos(1.3cm) and the embryonic age(11d~13d) also affected the callus formation. Third, the best conditions for the Agrobacterium transformation is as follows: A.tumefaciens concentration: OD600=0.8; inoculated time: 20min; co-culture time: 3 days; concentration of AS:100μmol/L, concentration of Cef:400mg/L,concentration of Kan:40mg/L . We obtained 117 resistant seedlings by Kan resistance screening, and 64 transplants of them were survival. Molecular detection on parts of them showed that there were 18 PCR positive plants. The results proved that the desired genes had been integrated into genomic DNA of maize.