Comparative analysis of transgenic rice plants obtained by Agrobacterium-mediated transformation and particle bombardment

We compared rice transgenic plants obtained by Agrobacterium-mediated and p article bombardment transformation by carrying out molecular analyses of th e T-0, T-1 and T-2 transgenic plants. Oryza sativa japonica rice (c.v. Taip ei 309) was transformed with a construct (pWNHG) that carried genes coding for neomycin phosphotransferase (nptII), hygromycin phosphotransferase (Hyg (r)), and beta -glucoronidase (GUS). Thirteen and fourteen transgenic lines produced via either method were selected and subjected to molecular analys is. Based on our data, we could draw the following conclusions. Average gen e copy numbers of the three transgenes were 1.8 and 2.7 for transgenic plan ts obtained by Agrobacterium and by particle bombardment, respectively. The percentage of transgenic plants containing intact copies of foreign genes, especially non-selection genes, was higher for Agrobacterium-mediated tran sformation. GUS gene expression level in transgenic plants obtained from Ag robacterium-mediated transformation was more stable overall the transgenic plant lines obtained by particle bombardment. Most of the transgenic plants obtained from the two transformation systems gave a Mendelian segregation pattern of foreign gens in T-1 and T-2 generations. Co-segregation was obse rved for liens obtained from particle bombardment, however, that was not al ways the case for T-1 lines obtained from Agrobacterium-mediated transforma tion. Fertility of transgenic plants obtained from Agrobacterium-mediated t ransformation was better. In summary, the Agrobacterium-mediated transforma tion is a good system to obtain transgenic plants with lower copy number, i ntact foreign gene and stable gene expression, while particle bombardment i s a high efficiency system to produce large number of transgenic plants wit h a wide range of gene expression.