Production of transgenic Japonica rice (Oryza sativa) cultivar, taichung 65, by the agrobacterium-mediated method

Transgenic rice plants of Taiwanese japonica rice cultivar, Taichung 65, were obtained by cocultivating scutellum calli with an Agrobacterium tumefaciens strain, EHA101, that carried a binary vector harboring the luciferase (Luc) gene driven by the CaMV35S promoter. The transformation efficiency of Taichung 65 was similar to that obtained by the methods routinely used for a transformable cultivar, Notohikari. There was no correlation between the length of the culture period (21 to 30 days) and the transient transformation efficiency in Taichung 65 and in Notohikari. In the T₀- and T₁-generations, the transgenes were integrated and stably expressed, indicating that the transgene was inherited to the next generation. The copy number of integrated transgene varied from one to three in the T₁-transformants, which was confirmed by Southern blot analysis. Moreover, approximately 60% of the T₁-transformants of Taichung 65 showed the LUC-positive phenotype. These results suggest that, in addition to Notohikari, Taichung 65 is a practical, transformable cultivar.