Planta

, Volume 220, Issue 4, pp 609–620

Biophysical consequences of remodeling the neutral side chains of rhamnogalacturonan I in tubers of transgenic potatoes

  • Peter Ulvskov
  • Helle Wium
  • David Bruce
  • Bodil Jørgensen
  • Karsten Bruun Qvist
  • Michael Skjøt
  • David Hepworth
  • Bernhard Borkhardt
  • Susanne Oxenbøll Sørensen
Original Article

DOI: 10.1007/s00425-004-1373-8

Cite this article as:
Ulvskov, P., Wium, H., Bruce, D. et al. Planta (2005) 220: 609. doi:10.1007/s00425-004-1373-8

Abstract

Two lines of transgenic potato (Solanum tuberosum L.) plants modified in their cell wall structure were characterized and compared to wild type with regard to biomechanical properties in order to assign functional roles to the particular cell wall polysaccharides that were targeted by the genetic changes. The targeted polymer was rhamnogalacturonan I (RG-I), a complex pectic polysaccharide comprised of mainly neutral oligosaccharide side chains attached to a backbone of alternating rhamnosyl and galacturonosyl units. Tuber rhamnogalacturonan I molecules from the two transformed lines are reduced in linear galactans and branched arabinans, respectively. The transformed tuber tissues were found to be more brittle when subjected to uniaxial compression and the side-chain truncation was found to be correlated with the physical properties of the tissue. Interpretation of the force–deflection curves was aided by a mathematical model that describes the contribution of the cellulose microfibrils, and the results lead to the proposition that the pectic matrix plays a role in transmitting stresses to the load-bearing cellulose microfibrils and that even small changes to the rheological properties of the matrix have consequences for the biophysical properties of the wall.

Keywords

Cell wall rheologyMathematical modelingPectinRhamnogalacturonanSolanumTransgenic potato

Abbreviations

RG-I (II)

Rhamnogalacturonan I (II)

T13.1

Transformant with truncated galactan side chains of RG-I

T7.2

Transformant with truncated arabinan side chains of RG-I

WT

Wild type

Copyright information

© Springer-Verlag 2004

Authors and Affiliations

  • Peter Ulvskov
    • 1
  • Helle Wium
    • 2
  • David Bruce
    • 3
  • Bodil Jørgensen
    • 1
  • Karsten Bruun Qvist
    • 2
  • Michael Skjøt
    • 1
  • David Hepworth
    • 3
  • Bernhard Borkhardt
    • 1
  • Susanne Oxenbøll Sørensen
    • 4
  1. 1.Biotechnology GroupDanish Institute of Agricultural SciencesFrederiksberg CDenmark
  2. 2.Department of Dairy and Food Science and Centre for Advanced Food StudiesThe Royal Veterinary and Agricultural UniversityFrederiksberg CDenmark
  3. 3.Biophysics GroupSilsoe Research InstituteBedfordUK
  4. 4.Plant Biochemistry Laboratory, Department of Plant BiologyRoyal Veterinary & Agricultural UniversityFrederiksberg CDenmark