Efficient, rapid, and reproducible system has been established for transformation of commercial varieties of rice via Agrobacterium tumefaciens. Calli induced from mature embryos of varieties E-yi 105, E-Wan 5, and Zhong-Shu-Wan-Geng (ZSWG) were cocultivated with the LBA4404 strain carrying the superbinary plasmid pTOK233. The frequency of transient gene expression in infected calli was as high as 100% under optimal conditions. Calli selected on hygromycin (50 mg L-1) medium for 6-8 wk showed uniform uidA gene expression. One hundred mature embryos of E-yi 105, E-Wan 5, and ZSWG yielded 107, 95, and 35 transgenic plantlets, respectively. Most transgenic plants of E-yi 105 reached fertile maturity in a controlled environment cabinet. Leaves, roots, immature embryos, anthers, and endosperm from these transgenic plants expressed the uidA gene. This rice transformation system provides a tool for introducing agronomically important genes into commercial varieties of rice and also offers the possibility of studying the mechanism of T-DNA transfer from A. tumefaciens into cells of monocotyledonous plants.
Zhang, J.; Xu, R.J.; Elliott, M.C.; Chen, D.F. Agrobacterium-mediated production of transgenic plants from mature embryos of commercial rice varieties. Presented at Third International Rice Genetics Symposium, Manila (Philippines), 16-20 Oct 1995. IRRI, Los Banos, Laguna, Philippines (1996) 702 pp.