Cloning and expression of flavonol synthase from Petunia hybrida

Abstract

Flavonols are important co‐pigments in flower colour and are also essential for pollen tube growth. In petunia, flavonol synthesis is controlled by the Fl locus. Flavonol synthase (FLS) belongs to the 2‐oxoglutarate‐dependent dioxygenase family. Dioxygenase gene fragments were amplified by PCR on cDNA made from FlFl and flfl flowers using degenerate primers designed from conserved dioxygenase sequences. A petunia petal cDNA library was screened for clones that hybridized more strongly to the Fl PCR products than the fl PCR products. A full‐length cDNA clone identified by this screening exhibited FLS activity when expressed in yeast. FLS gene expression is developmentally regulated during flower development. Antisense expression of an FLS cDNA clone in petunia markedly reduced flavonol synthesis in petals. RFLP mapping showed that the FLS gene is linked to Fl, suggesting that Fl is the structural gene for FLS.

Metabolomic and genetic analyses of flavonol synthesis in Arabidopsis thaliana support the in vivo involvement of leucoanthocyanidin dioxygenase

“…DihydroXavonol precursors, usually channelled to Xavonols, are converted by DFR to build anthocyanidins. A similar eVect was observed previously by antisense expression of a petunia FLS cDNA in petunia and tobacco, which markedly reduced Xavonol synthesis in petals and concurrently intensiWed red Xower pigmentation (Holton et al 1993). In the regulatory A. thaliana mutant pfg1 pfg2 pfg3, accumulation of Xavonols is blocked while the accumulation of anthocyanins is increased (Stracke et al 2007).…”

“…FLS activity was subsequently detected in Xower tissues of Matthiola incana (Spribille and Forkmann 1984), Petunia hybrida (Forkmann et al 1986) and Dianthus caryophyllus (Forkmann 1991). The Wrst FLS cDNA was cloned from P. hybrida and identiWed by functional expression in yeast (Holton et al 1993). Transformation of petunia or tobacco with antisense FLS intensiWed red Xower pigmentation (Holton et al 1993).…”

“…The Wrst FLS cDNA was cloned from P. hybrida and identiWed by functional expression in yeast (Holton et al 1993). Transformation of petunia or tobacco with antisense FLS intensiWed red Xower pigmentation (Holton et al 1993). Further FLS cDNAs were isolated from Arabidopsis thaliana (Pelletier et al 1997;Wisman et al 1998), Eustoma grandiXorum, Solanum tuberosum (van Eldik et al 1997), Malus domestica and Matthiola incana (database submissions AF119095 and AF001391).…”

Comprehensive analyses of anthocyanin and related compounds to understand flower color change in ion-beam mutants of cyclamen (Cyclamen spp.) and carnation (Dianthus caryophyllus)

“…reported by Holton et al (1993) and Davies et al (2003); inhibition of avonol synthase by introduction of the antisense transgene construct caused deeper color change of petunia flowers. A decrease in the metabolism of dihydro avonol into avonols probably causes activation of metabolism into anthocyanin, resulting in the increased anthocyanin concentration and formation of colored tissue.…”

Flower color modification of Petunia hybrida commercial varieties by metabolic engineering

“…The cDNAs encoding petunia F3Ј,5ЈH (Holton et al 1993a), FLS (Holton et al 1993b), F3ЈH (Brugliera et al 1999), anthocyanidin 3-glucoside rhamnosyltransferase (3RT, Brugliera et al 1994), anthocyanidin 3-rutinoside acyltransferase (AR-AT, Brugliera and Koes, unpublished results), and flavanone 3-hydroxylase (F3H, unpublished results) were kindly provided by Florigene Ltd. Rose DFR and FLS cDNAs and torenia flavone synthase (FNS) cDNA were described previously (Tanaka et al 1995;Tanaka et al 2003;Akashi et al 1999, respectively).…”