title: p-Hydroxybenzoyl-glucose is a zwitter donor for the biosynthesis of 7-polyacylated anthocyanin in Delphinium.
abstract: The blue color of delphinium (Delphinium grandiflorum) flowers is produced by two 7-polyacylated anthocyanins, violdelphin and cyanodelphin. Violdelphin is derived from the chromophore delphinidin that has been modified at the 7-position by Glc and p-hydroxybenzoic acid (pHBA) molecules. Modification of violdelphin by linear conjugation of Glc and pHBA molecules to a Glc moiety at the 7-position produces cyanodelphin. We recently showed that anthocyanin 7-O-glucosylation in delphinium is catalyzed by the acyl-Glc-dependent anthocyanin glucosyltransferase (AAGT). Here, we sought to answer the question of which enzyme activities are necessary for catalyzing the transfer of Glc and pHBA moieties to 7-glucosylated anthocyanin. We found that these transfers were catalyzed by enzymes that use p-hydroxybenzoyl-Glc (pHBG) as a bifunctional acyl and glucosyl donor. In addition, we determined that violdelphin is synthesized via step-by-step enzymatic reactions catalyzed by two enzymes that use pHBG as an acyl or glucosyl donor. We also isolated a cDNA encoding a protein that has the potential for p-hydroxybenzoylation activity and two AAGT cDNAs that encode a protein capable of adding Glc to delphinidin 3-O-rutinoside-7-O-(6-O-[p-hydroxybenzoyl]-glucoside) to form violdelphin.
authors.affiliation: Department of Biotechnology and Life Science, Faculty of Engineering, Tokyo University of Agriculture and Technology, Koganei, Tokyo 184-8588, Japan.
authors.forename: Yuzo
authors.initials: Y
authors.lastname: Nishizaki
authors.forename: Motoki
authors.initials: M
authors.lastname: Yasunaga
authors.forename: Emi
authors.initials: E
authors.lastname: Okamoto
authors.forename: Mitsutoshi
authors.initials: M
authors.lastname: Okamoto
authors.forename: Yukio
authors.initials: Y
authors.lastname: Hirose
authors.forename: Masaatsu
authors.initials: M
authors.lastname: Yamaguchi
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Ozeki
authors.forename: Nobuhiro
authors.initials: N
authors.lastname: Sasaki
mesh_terms: D000217:Acyltransferases / Q000235:genetics / Q000378:metabolism*; D000872:Anthocyanins / Q000096:biosynthesis* / Q000737:chemistry; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics; D031882:Delphinium / Q000737:chemistry* / Q000201:enzymology / Q000235:genetics; D035264:Flowers / Q000737:chemistry / Q000201:enzymology; D005947:Glucose / Q000737:chemistry*; D062385:Hydroxybenzoates / Q000737:chemistry; D008969:Molecular Sequence Data; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: D000872:Anthocyanins; D018076:DNA, Complementary; D062385:Hydroxybenzoates; D010940:Plant Proteins; C088344:violdelphin; C010705:delphinidin-3-rutinoside; D000217:Acyltransferases; D005947:Glucose