title: Diversification of the duplicated F3h genes in Triticeae.
abstract: The F3h gene encodes the flavonoid synthesis enzyme flavanone 3-hydroxylase. Unlike most plant genomes, the bread wheat (Triticum aestivum L.) B genome has two, rather than just one F3h copy. The paralogous F3h-B2 sequence was isolated by PCR and shown to be transcribed, but its predicted polypeptide differed from the typical F3H sequence at a number of the conserved residues associated with its putative substrate-binding sites. The F3h-B2 promoter region was highly divergent from that of F3h-B1, and the transcriptional profiles of the two genes were distinct. Among a panel of 95 Triticeae accessions, representing 24 species, an F3h-2 copy was only detected within those carrying a B, S, G, or an R genome. Analysis of the coding sequence divergence suggested that a small segmental duplication occurred early in the evolution of the Triticeae tribe. The duplicated F3h copy appears to have acquired a novel function in the progenitor of the closely related B, G, and S genomes, as well as in the R genome. In other Triticeae genomes, the F3h-2 paralog may have been lost following pseudogenization.
authors.forename: E K
authors.initials: EK
authors.lastname: Khlestkina
authors.forename: O B
authors.initials: OB
authors.lastname: Dobrovolskaya
authors.forename: I N
authors.initials: IN
authors.lastname: Leonova
authors.forename: E A
authors.initials: EA
authors.lastname: Salina
mesh_terms: D000595:Amino Acid Sequence; D001665:Binding Sites; D005075:Biological Evolution; D017124:Conserved Sequence; D020440:Gene Duplication; D020131:Genes, Duplicate; D017343:Genes, Plant; D018745:Genome, Plant; D006899:Mixed Function Oxygenases / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D006109:Poaceae / Q000235:genetics*; D014908:Triticum / Q000235:genetics
chemical_list: D006899:Mixed Function Oxygenases; C048797:flavanone 3-dioxygenase