Compared with petunia, C. hybrida has many desirable characteristics, such as diversity of flower colors, along with pH tolerance and vigorous growth. The function of DFR from C. hybrida has not been studied yet. The amino acid sequence of CaDFR is similar to tomato DFR. In our study, the overexpression of CaDFR in petunia
caused flower color alteration as expected. The DFR activities were varied consistent with the change of flower color. The lighter flower color is, the lower DFR activity it will be. The differential change in the same variety may be due to the number of integrated copies of the gene or by its integration position in the host genome. In transformant Lx-H26, the DFR activity was lower than control, so three copies of DFR integration would suppression of gene expression,