title: Glycosyltransferase efficiently controls phenylpropanoid pathway.
abstract: BACKGROUND
  In a previous study, anthocyanin levels in potato plants were increased by manipulating genes connected with the flavonoid biosynthesis pathway. However, starch content and tuber yield were dramatically reduced in the transgenic plants, which over-expressed dihydroflavonol reductase (DFR).
  
  
  RESULTS
  Transgenic plants over-expressing dihydroflavonol reductase (DFR) were subsequently transformed with the cDNA coding for the glycosyltransferase (UGT) of Solanum sogarandinum in order to obtain plants with a high anthocyanin content without reducing tuber yield and quality. Based on enzyme studies, the recombinant UGT is a 7-O-glycosyltransferase whose natural substrates include both anthocyanidins and flavonols such as kaempferol and quercetin. In the super-transformed plants, tuber production was much higher than in the original transgenic plants bearing only the transgene coding for DFR, and was almost the same as in the control plants. The anthocyanin level was lower than in the initial plants, but still higher than in the control plants. Unexpectedly, the super-transformed plants also produced large amounts of kaempferol, chlorogenic acid, isochlorogenic acid, sinapic acid and proanthocyanins.
  
  
  CONCLUSIONS
  In plants over-expressing both the transgene for DFR and the transgene for UGT, the synthesis of phenolic acids was diverted away from the anthocyanin branch. This represents a novel approach to manipulating phenolic acids synthesis in plants.
authors.affiliation: Faculty of Biotechnology, Wroclaw University, Przybyszewskiego 63/77, 51-148 Wroclaw, Poland. anna.aksamit@interia.pl
authors.forename: Anna
authors.initials: A
authors.lastname: Aksamit-Stachurska
authors.forename: Alina
authors.initials: A
authors.lastname: Korobczak-Sosna
authors.forename: Anna
authors.initials: A
authors.lastname: Kulma
authors.forename: Jan
authors.initials: J
authors.lastname: Szopa
mesh_terms: D000429:Alcohol Oxidoreductases / Q000235:genetics / Q000378:metabolism*; D000872:Anthocyanins / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant / Q000502:physiology; D024861:Genetic Enhancement / Q000379:methods*; D016695:Glycosyltransferases / Q000235:genetics / Q000378:metabolism*; D010666:Phenylpropionates / Q000378:metabolism*; D030821:Plants, Genetically Modified / Q000502:physiology*; D015398:Signal Transduction / Q000502:physiology; D032322:Solanum / Q000502:physiology*
chemical_list: D000872:Anthocyanins; D010666:Phenylpropionates; D000429:Alcohol Oxidoreductases; C056570:dihydroflavanol 4-reductase; D016695:Glycosyltransferases