Genetic control of chalcone-flavanone isomerase activity inCallistephus chinensis

✍ Scribed by B. Kuhn; G. Forkmann; W. Seyffert

• Publisher: Springer-Verlag
• Year: 1978
• Tongue: English
• Weight: 453 KB
• Volume: 138
• Category: Article
• ISSN: 0032-0935
• DOI: 10.1007/bf00386811

✦ Synopsis

A mutant blocked in anthocyanin synthesis leads to an accumulation of 4,2',4',6'-tetrahydroxychalcone-2'-glucoside (isosalipurposide) in blossoms of Callistephus chinensis (L.) Nees, whereas in genotypes with the wild-type allele, higher oxidized flavonoids and anthocyanins are synthesized. Measurements of chalcone-flavanone isomerase activity of 18 lines of Callistephus chinensis showed a clear correlation between accumulation of chalcone in the recessive genotypes (ch ch) and deficiency of this enzyme activity. Both the chemogenetic and the enzymologic evidence lead to the following conclusions: 1. The first product of the synthesis of the flavonoid skeleton should be tetrahydroxychalcone.-2. The chalconeflavanone isomerase catalyzes the formation of flavanone from chalcone in a stereospecific way and therewith furnishes the substrate for the further reactions in the flavonoid biosynthesis.