Biosynthesis and regulation of betalains in red beet

Abstract

The red beet (Beta vulgaris) gets its distinctive color from betalains, one of the major plant pigment groups. Betalain-bearing plants appeared among plants of the families Caryophyllales, of which red beet is one of the main crops. Betalain pigments are classi fi ed into two groups-red betacyanin and yellow betaxanthin- and they all contain two atoms of nitrogen, unlike the other major plant pigments, the anthocyanins and fl avonoids. Whereas the biosynthetic pathways of anthocyanins and fl avonoids are reasonably well known, those of the betalains remain unclear. However, several important genes encoding the enzymes involved in betalain biosynthesis have now been identi fi ed. In this section, several distinctive enzymes of betalain biosynthesis are described and the unsolved reaction steps of the proposed pathway are discussed.