Efficient transgene expression in chrysanthemum, Chrysanthemum morifolium ramat., with the promoter of a gene for tobacco elongation factor 1α protein

We investigated the usefulness of the promoter of a gene for tobacco elongation factor 1 alpha protein (EF1 alpha) for transgene expression in the chrysanthmum (Chrysanthemum morifolium Ramat.). The EF1 alpha promoter was fused to the beta-glucuronidase gene (gus) and introduced into the chrysanthemum. We obtained 238 putative transformants and GUS assay of the leaves of the in vitro plants revealed that 29.0% (69/238) of the putative plants were GUS-positive. The plants in the greenhouse that were 20 months after regeneration still showed a GUS activity in their leaves and petals. The tobacco EF1 alpha promoter expressed the transgene more efficiently than the 35S prornoter of Cauliflower mosaic virus and could be used for transgene expression in chrysanthemum.