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 DODA (Dopa-dioxygenase) and PAP (Phytolacca americana polyphenol oxidase) which might be involved in betacyanin biosynthesis from Phytolacca americana. Phytolacca DODA cDNA showed high degree of homology (approximately 70%) with DODAs from other Caryophyllales, and had a conserved motif found in DODAs of betacyanin synthesizing plants. PAP showed very high degree of homology (95%) with known PAP1. Spatial and temporal expression of DODA and PAP in various organs of Phytolacca plants has been investigated by semi-quantitative RT-PCR. Accumulation of DODA transcripts has been found not only in betalain-containing cells but in green or white cells. Close correlation between betacyanin accumulation and expression of PAP was observed.
