Genome-wide analysis of the UDP-glucose dehydrogenase gene family in Arabidopsis, a key enzyme for matrix polysaccharides in cell walls

J Exp Bot. 2007;58(13):3609-21. doi: 10.1093/jxb/erm209.


Arabidopsis cell walls contain large amounts of pectins and hemicelluloses, which are predominantly synthesized via the common precursor UDP-glucuronic acid. The major enzyme for the formation of this nucleotide-sugar is UDP-glucose dehydrogenase, catalysing the irreversible oxidation of UDP-glucose into UDP-glucuronic acid. Four functional gene family members and one pseudogene are present in the Arabidopsis genome, and they show distinct tissue-specific expression patterns during plant development. The analyses of reporter gene lines indicate gene expression of UDP-glucose dehydrogenases in growing tissues. The biochemical characterization of the different isoforms shows equal affinities for the cofactor NAD(+) ( approximately 40 microM) but variable affinities for the substrate UDP-glucose (120-335 microM) and different catalytic constants, suggesting a regulatory role for the different isoforms in carbon partitioning between cell wall formation and sucrose synthesis as the second major UDP-glucose-consuming pathway. UDP-glucose dehydrogenase is feedback inhibited by UDP-xylose. The relatively (compared with a soybean UDP-glucose dehydrogenase) low affinity of the enzymes for the substrate UDP-glucose is paralleled by the weak inhibition of the enzymes by UDP-xylose. The four Arabidopsis UDP-glucose dehydrogenase isoforms oxidize only UDP-glucose as a substrate. Nucleotide-sugars, which are converted by similar enzymes in bacteria, are not accepted as substrates for the Arabidopsis enzymes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Arabidopsis / enzymology*
  • Arabidopsis / genetics*
  • Arabidopsis Proteins / genetics
  • Arabidopsis Proteins / metabolism
  • Cell Wall / metabolism*
  • Gene Expression Regulation, Plant
  • Genome, Plant
  • Multigene Family*
  • Phylogeny
  • Plants, Genetically Modified
  • Polysaccharides / metabolism*
  • Protein Isoforms
  • Uridine Diphosphate Glucose Dehydrogenase / genetics*
  • Uridine Diphosphate Glucose Dehydrogenase / metabolism*


  • Arabidopsis Proteins
  • Polysaccharides
  • Protein Isoforms
  • Uridine Diphosphate Glucose Dehydrogenase