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

  • 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+ (~40 µM) but variable affinities for the substrate UDP-glucose (120–335 µM) 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.

Download full text files

Export metadata

Author:Michaela Klinghammer, Raimund Tenhaken
Pubmed Id:
Parent Title (English):The journal of experimental botany
Publisher:Oxford Univ. Press
Place of publication:Oxford
Document Type:Article
Year of Completion:2007
Date of first Publication:2007/10/01
Publishing Institution:Universitätsbibliothek Johann Christian Senckenberg
Release Date:2008/10/01
Tag:UDP-glucose dehydrogenase; cell wall precursor; gene expression; hemicellulose; nucleotide-sugar
Page Number:13
First Page:3609
Last Page:3621
(c) 2007 The Author(s). This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License ( which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
Source:The Journal of Experimental Botany 2007 58(13):3609-3621; doi:10.1093/jxb/erm209
Institutes:Biowissenschaften / Biowissenschaften
Dewey Decimal Classification:5 Naturwissenschaften und Mathematik / 58 Pflanzen (Botanik) / 580 Pflanzen (Botanik)
Sammlungen:Sammlung Biologie / Sondersammelgebiets-Volltexte
Licence (German):License LogoCreative Commons - Namensnennung-Nicht kommerziell 2.0