Abstract
Two types of red pigment, anthocyanins and betacyanins, never occur together in the same plants. Although anthocyanins are widely distributed in higher plants, betacyanins are characteristic constituents of most species of Caryophyllales.
We have cloned cDNAs of DOPA dioxygenase (DOD) which is known as a key enzyme in betalain biosynthesis from red cell cultures of Phytolacca americana. Phytolacca DOD (PaDOD) had a conserved motif found in DODs of betacyanin synthesizing plants. Expression patterns of PaDOD in cell cultures and in various organs of Phytolacca plants were investigated by semi-quantitative RT-PCR. In red cell cultures, the highest expression of PaDOD was observed just before betacyanin accumulation. In Phytolacca plants, the transcripts of PaDOD were found not only in betalain-containing cells but also in green or white cells. Further studies on the function of DOD in Phytolacca plants are in progress.
