A Transcript Profiling Approach Reveals an Epicatechin-Specific Glucosyltransferase Expressed in the Seed Coat of Medicago Truncatula

Proc Natl Acad Sci U S A. 2008 Sep 16;105(37):14210-5. doi: 10.1073/pnas.0805954105. Epub 2008 Sep 4.

Abstract

Expression of the Arabidopsis TRANSPARENT TESTA 2 (TT2) MYB family transcription factor leads to massive accumulation of proanthocyanidins (PAs) in hairy roots of Medicago truncatula. Microarray analysis showed that TT2 induces genes for flavonoid/PA biosynthesis, transcription factors, and a large number of genes of unknown function. A second microarray dataset identified genes that were preferentially expressed in the M. truncatula seed coat. Comparison of the two datasets defines target genes for steps that are yet unidentified in PA biosynthesis and accumulation. Of these genes, a glycosyltransferase, UGT72L1, was active specifically toward the PA precursor (-)-epicatechin, and its expression pattern in developing seeds correlated with the presence of epicatechin glucoside and accumulation of PAs. UGT72L1 may be involved in the production of epicatechin 3'-O-glucoside in the seed coat as a key step in PA biosynthesis or its regulation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anthocyanins / biosynthesis
  • Catechin / metabolism*
  • Flavonols / biosynthesis
  • Gene Expression Profiling
  • Gene Expression Regulation, Plant*
  • Glucosides / biosynthesis
  • Glucosyltransferases / genetics
  • Glucosyltransferases / metabolism*
  • Medicago truncatula / enzymology*
  • Medicago truncatula / genetics*
  • Molecular Sequence Data
  • Phenotype
  • Plant Roots / enzymology
  • Seeds / anatomy & histology
  • Seeds / enzymology*
  • Seeds / genetics
  • Substrate Specificity
  • Transcription, Genetic / genetics*
  • Up-Regulation

Substances

  • Anthocyanins
  • Flavonols
  • Glucosides
  • Catechin
  • Glucosyltransferases

Associated data

  • GENBANK/EU434684