Isolation and characterization of a flavonoid 3'-hydroxylase cDNA clone corresponding to the Ht1 locus of Petunia hybrida

Plant J. 1999 Aug;19(4):441-51. doi: 10.1046/j.1365-313x.1999.00539.x.


We have isolated a cDNA clone that corresponds to the Ht1 locus of petunia which controls the hydroxylation of dihydrokaempferol to dihydroquercetin and of naringenin to eriodictyol by the action of flavonoid 3'-hydroxylase (F3'H). The cDNA encodes a 512 amino acid polypeptide with regions of similarity to petunia flavonoid 3',5'-hydroxylases (F3'5'H). Both F3'H and F3'5'H are cytochromes P450 and are key enzymes in the flavonoid pathway leading to the production of the coloured anthocyanins. The F3 'H transcript is most abundant in petals from flowers at an early stage of development and levels decline as the flower matures. Transcripts are also detected in the ovaries, sepals, peduncles, stems and anthers of the petunia plant. No or very reduced levels of transcripts are detected in ht1/ht1 lines. This is the first report of isolation of a F3 'H cDNA clone from any species.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Anthocyanins / metabolism
  • Base Sequence
  • Cloning, Molecular
  • Cytochrome P-450 Enzyme System / chemistry
  • Cytochrome P-450 Enzyme System / genetics*
  • Cytochrome P-450 Enzyme System / metabolism
  • Flavanones*
  • Flavonoids / metabolism
  • Gene Expression Regulation, Plant
  • Genes, Plant / genetics*
  • Genetic Complementation Test
  • Genetic Linkage / genetics
  • Hybridization, Genetic
  • Mixed Function Oxygenases / chemistry
  • Mixed Function Oxygenases / genetics*
  • Mixed Function Oxygenases / metabolism
  • Molecular Sequence Data
  • Mutation / genetics
  • Phylogeny
  • Plant Structures / enzymology
  • Plant Structures / genetics
  • RNA, Messenger / analysis
  • RNA, Messenger / genetics
  • Sequence Homology, Amino Acid
  • Solanaceae / enzymology
  • Solanaceae / genetics*
  • Yeasts / genetics


  • Anthocyanins
  • Flavanones
  • Flavonoids
  • RNA, Messenger
  • Cytochrome P-450 Enzyme System
  • Mixed Function Oxygenases
  • flavonoid 3'-hydroxylase
  • naringenin
  • eriodictyol

Associated data

  • GENBANK/AF155332