Plant Molecular Biology

, Volume 57, Issue 2, pp 285–301

Characterisation and expression of the pathway from UDP-glucose to UDP-xylose in differentiating tobacco tissue

  • Laurence V. Bindschedler
  • Edward Wheatley
  • Elaine Gay
  • Jim Cole
  • Amanda Cottage
  • G. Paul Bolwell
Article

DOI: 10.1007/s11103-004-7795-7

Cite this article as:
Bindschedler, L.V., Wheatley, E., Gay, E. et al. Plant Mol Biol (2005) 57: 285. doi:10.1007/s11103-004-7795-7

Abstract

The pathway from UDP-glucose to UDP-xylose has been characterised in differentiating tobacco tissue. A xylogenic suspension cell culture of tobacco has been used as a source for the purification of the enzymes responsible for the oxidation of UDP-glucose to UDP-glucuronic acid and its subsequent decarboxylation to UDP-xylose. Protein purification and transcriptional studies show that two possible candidates can contribute to the first reaction. Most of the enzyme activity in the cultured cells could be accounted for by a protein with an Mr of 43 kDa which had dual specificity for UDP-glucose and ethanol. The cognate cDNA, with similarity to alcohol dehydrogenases (NtADH2) was expressed in E. coli to confirm the dual specificity. A second UDP-glucose dehydrogenase, corresponding to the monospecific form, ubiquitous amongst plants and animals, could not be purified from the tobacco cell cultures. However, two cDNAs were cloned with high similarity to the family of UDP-glucose dehydrogenases. Transcripts of both types of dehydrogenase showed highest expression in tissues undergoing secondary wall synthesis. The UDP-glucuronate decarboxylase was purified as polypeptides of Mr 87 and 40 kDa. Peptide fingerprinting of the latter polypeptide identified it as a form of UDP-glucuronate decarboxylase and functionality was established by expressing the cognate cDNA in E. coli. Expression of 40 kDa polypeptide and its corresponding mRNA was also found to be highest in tissues associated with secondary wall formation.

Keywords

hemicellulose UDP-glucose dehydrogenase UDP-glucuronate decarboxylase UDP-xylose tobacco xylan xylogenesis 

Abbreviations

ADH

alcohol dehydrogenase

Mr

apparent molecular mass

Nt

Nicotiana tabacum

UDPGlc

UDP-glucose

UDPGIcA

UDP-glucuronic acid

UDPGlcADCX

UDP-glucuronate decarboxylase

UDP

glucose dehydrogenase

UDP

uridine diphosphate

UDPXyl

UDP-xylose

UXS

UDP-xylose synthase

Copyright information

© Springer 2005

Authors and Affiliations

  • Laurence V. Bindschedler
    • 1
  • Edward Wheatley
    • 1
    • 3
  • Elaine Gay
    • 1
  • Jim Cole
    • 2
  • Amanda Cottage
    • 2
  • G. Paul Bolwell
    • 1
  1. 1.School of Biological Sciences, Royal HollowayUniversity of LondonEghamUK
  2. 2.Advanced Technologies (Cambridge) Ltd.CambridgeUK
  3. 3.National Institute for Medical ResearchLondonUK