| 1 | Author
| K. Stich, T. Eidenberger, F. W. Urst, G. Forkm | Requires cookie* | | Title
| Flavonol Synthase Activity and the Regulation of Flavonol and Anthocyanin Biosynthesis during Flower Development in Dianthus caryophyllus L. (Carnation)  | | | Abstract
| Flavonol synthase (FLS) was demonstrated in crude extracts from flower buds o f Dianthus caryophyllus (carnation). The enzyme catalyzed the conversion o f dihydrokaempferol and dihydroquercetin to kaempferol and quercetin, respectively. The reaction required 2-oxoglutarate, ferrous ion and ascorbate as co-factors and had a pH optimum at about 7.4. The demonstration o f FLS activity allowed comparative studies on flavonol and anthocyanin biosynthesis during bud and flower developm ent. Besides FLS the flavonoid enzymes chal cone synthase (CHS), flavanone 3-hydroxylase (FH T) and dihydroflavonol 4-reductase (D F R) were measured. D F R is specifically involved in anthocyanin synthesis, while CHS and FHT provide dihydroflavonol, the com m on substrate for both FLS and D F R . Maximum ex pression o f CHS, FHT and FLS activity was already observed in small buds, whereas D FR activity started to increase much later and reached its highest level in opened flowers. A sub stantial correlation was observed between the time courses o f FLS and D F R activity and the accumulation o f flavonols and anthocyanins, respectively. The com petition o f FLS and D F R for dihydroflavonols was found to be largely circumvented by different substrate specificities and by the sequential expression o f the two enzymes. Both flavonols and anthocyanins are obviously not, or only to some extent, subject to degradation. | | |
Reference
| Z. Naturforsch. 47c, 553 (1992); received February 17/April 21 1992 | | |
Published
| 1992 | | |
Keywords
| Anthocyanins, Flavonoid Enzymes, Flavonols, Flower D evelopm ent, Dianthus caryophyllus | | |
Similar Items
| Find | | DEBUG INFO
| | | | TEI-XML for
| default:Reihe_C/47/ZNC-1992-47c-0553.pdf | | | Identifier
| ZNC-1992-47c-0553 | | | Volume
| 47 | |
|