title: Differential expression of flavonoid 3'-hydroxylase during fruit development establishes the different B-ring hydroxylation patterns of flavonoids in Fragaria × ananassa and Fragaria vesca.
abstract: Flavonoid 3'-hydroxylase (F3'H) was studied for the first time in different Fragaria species. The cDNA clones isolated from unripe and ripe fruits of Fragaria x ananassa (garden strawberry) and Fragaria vesca (wild strawberry) showed high similarity (99% at the amino acid level) to the publically available F. vesca genome sequence and no significant differences could be identified between species and developmental stages of the fruits. In contrast, the genomic F3'H clones showed differences in the non-coding regions and 5'-flanking elements. The recombinant F3'Hs were functionally active and showed high specificity for naringenin, dihydrokaempferol, and kaempferol, whereas apigenin was only a minor substrate. During fruit development, a clear difference in the F3'H expression was observed between F. × ananassa and F. vesca. While a drastic decline of F3'H expression occurred during fruit ripening in F. × ananassa, F3'H in F. vesca was highly expressed in all stages. This was reflected by the anthocyanin composition, which showed a prevalence of pelargonidin in ripe fruits of F. × ananassa, whereas F. vesca had a high content of cyanidin. Screening of 17 berry species for their anthocyanin and flavonol composition showed that the prevalence of monohydroxylated anthocyanins makes garden strawberry unique among all other fruit species indicating that selection of bright red color during strawberry breeding, which consumers typically associate with freshness and ripeness, has selected phenotypes with a special biochemical background.
authors.affiliation: Technische Universität Wien, Institut für Verfahrenstechnik, Umwelttechnik und Technische Biowissenschaften, Getreidemarkt 9/1665, A-1060 Wien, Austria. Electronic address: jthill@mail.zserv.tuwien.ac.at.
authors.forename: Jana
authors.initials: J
authors.lastname: Thill
authors.forename: Silvija
authors.initials: S
authors.lastname: Miosic
authors.forename: Tek Prasad
authors.initials: TP
authors.lastname: Gotame
authors.forename: Maja
authors.initials: M
authors.lastname: Mikulic-Petkovsek
authors.forename: Christian
authors.initials: C
authors.lastname: Gosch
authors.forename: Robert
authors.initials: R
authors.lastname: Veberic
authors.forename: Anja
authors.initials: A
authors.lastname: Preuss
authors.forename: Wilfried
authors.initials: W
authors.lastname: Schwab
authors.forename: Franci
authors.initials: F
authors.lastname: Stampar
authors.forename: Karl
authors.initials: K
authors.lastname: Stich
authors.forename: Heidi
authors.initials: H
authors.lastname: Halbwirth
mesh_terms: D003577:Cytochrome P-450 Enzyme System / Q000235:genetics / Q000378:metabolism*; D005419:Flavonoids / Q000378:metabolism*; D031985:Fragaria / Q000201:enzymology* / Q000378:metabolism*; D005638:Fruit / Q000235:genetics / Q000378:metabolism*; D006900:Hydroxylation; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: D005419:Flavonoids; D010940:Plant Proteins; D003577:Cytochrome P-450 Enzyme System; C038888:flavonoid 3'-hydroxylase
keywords: Anthocyanins; Flavonoid 3′-hydroxylase (F3′H); Fruit color; Fruit ripening; Hydroxylation pattern; Pelargonidin; Strawberry (Fragaria sp.)