Figure 6.

The specificity of the Pg DODA gene is demonstrated by biolistic complementation of the betalain pathway in the white petals of P. grandiflora plants deficient in DODA. A pNco DODA expression vector containing full-length Pg DODA driven by a CaMV promoter has been used with pDsRed2 vector as a positive control. A, Yellow spots revealed after biolistic transformation of a white petal from a plant with yellow genetic background. B, Close-up of a cell accumulating betaxanthins in its vacuole. C, The same cell displaying the DsRed2 fluorescent protein modified to an orange one by the fluorescence of the betaxanthins. D, Violet spots revealed in a white petal from a plant with a violet genetic background. E, Close-up of a cell accumulating betacyanins. F, The same cell displaying the DsRed2 fluorescent protein. The red fluorescence hue from DsRed2 was slightly modified by filtration through yellow betaxanthin or violet betacyanin pigments (allowing for color differences between C and F). Bars = 200 μm in A and D and 20 μm in B, C, E, and F.