Biochemistry and molecular biology of the late-stage of biosynthesis of anthocyanin: lessons from Perilla frutescens as a model plant.

Although substantial progress has been made on the molecular genetics of anthocyanin biosynthesis, the biochemistry of some components, such as anthocyanidin synthase, are not fully understood. To explore anthocyanin formation in more detail, and in particular, the late-stage of the biosynthetic pathway, Perilla frutescens (Labiatae) was chosen as a model plant. Two chemo-varietal forms exist in P. frutescens, the pigmented red form and, in striking contrast, the non-pigmented green form, which contains only a trace amount of anthocyanin in the leaves and stems. Using this plant, we investigated the biochemical characteristics of anthocyanidin synthase and two anthocyanin glycosyltransferases, and in addtion we used this plant to investigate the expression and regulation of flavonoid biosynthesis genes. P. frutescens represents a good model plant for investigating anthocyanin biosynthesis. Further exploitation of this model system will require the establishment of a suitable transformation system for P. frutescens. Future work will be directed towards further characterization of the chemo-varietal forms and investigating their evolution from the ancestral form. Contents I. Introduction 9 II. Biosynthetic enzymes and their genes 11 III. Regulation of gene expression and regulatory genes 19 IV. Conclusions and future prospects 21 References 21.