Relationship between Flower Development, Anthocyanin Accumulation and Activity o f Enzymes Involved in Flavonoid Biosynthesis in Matthiola incana R. Br

The activity of five enzymes concerning anthocyanin biosynthesis as well as the anthocyanin accumulation were studied during the development of buds and flowers of Matthiola incana. The investigations included the first three enzymes in the anthocyanin pathway, chalcone synthase, chalcone isomerase and flavanone 3-hydroxylase, and the flavonoid-modifying enzymes, flavonoid 3'-hydroxylase and flavonoid 3-O-glucosyltransferase. The bud and flower development was subdivided into eight stages with respect to morphological criteria. On a fresh weight basis, a substantial correlation between anthocyanin content and the activities of all of the five enzymes were found in the various developmental stages. Furthermore, the anthocyanins formed are obviously not or only less subject to degradation. Although all maxima of activity proved to be in buds, clear differences were observed between the five enzymes with regard to increase and stage of maximum activity. The isolation of other enzymes involved in flavonoid biosynthesis is likely to be most successful in the bud stages.