Fig. 3.

Betalain pathway with comparision of analogous structures pigmented with anthocyanin or betalain. The six left panels are representative flowers, fruits and roots, with the far left panels pigmented with anthocyanins and the right with betalains. Upper left, Petunia flower; upper right, cactus flower; middle left, blueberries; middle right, malabar spinach berries; lower left, radish roots; lower right, beet roots. The betalain pathway is shown on the right, with the enzymatic steps regulated by BvMYB1 indicated with arrows. The condensation of betalamic acid with cyclo-DOPA to produce red betalains, or amine compounds to produce yellow betalains is spontaneous. Betalains are trafficked to the vacuole by unknown means. Note that betacyanins are usually modified, often by glycosylation on the cyclo-DOPA moiety (not shown).