p-Hydroxybenzoyl-glucose is a zwitter donor for the biosynthesis of 7-polyacylated anthocyanin in Delphinium

Plant Cell. 2013 Oct;25(10):4150-65. doi: 10.1105/tpc.113.113167. Epub 2013 Oct 31.

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acyltransferases / genetics
  • Acyltransferases / metabolism*
  • Anthocyanins / biosynthesis*
  • Anthocyanins / chemistry
  • Cloning, Molecular
  • DNA, Complementary / genetics
  • Delphinium / chemistry*
  • Delphinium / enzymology
  • Delphinium / genetics
  • Flowers / chemistry
  • Flowers / enzymology
  • Glucose / chemistry*
  • Hydroxybenzoates / chemistry
  • Molecular Sequence Data
  • Plant Proteins / genetics
  • Plant Proteins / metabolism*

Substances

  • Anthocyanins
  • DNA, Complementary
  • Hydroxybenzoates
  • Plant Proteins
  • violdelphin
  • delphinidin-3-rutinoside
  • Acyltransferases
  • Glucose

Associated data

  • GENBANK/AB811444
  • GENBANK/AB811447
  • GENBANK/AB811448
  • GENBANK/AB811449
  • GENBANK/AB811450
  • GENBANK/AB819286
  • GENBANK/AB819287
  • GENBANK/AB819288
  • GENBANK/AB819289
  • GENBANK/AB844439
  • GENBANK/AB844440
  • GENBANK/AB844441