, Volume 247, Issue 4, pp 887–897 | Cite as

The effect of altered lignin composition on mechanical properties of CINNAMYL ALCOHOL DEHYDROGENASE (CAD) deficient poplars

  • Merve Özparpucu
  • Notburga Gierlinger
  • Ingo Burgert
  • Rebecca Van Acker
  • Ruben Vanholme
  • Wout Boerjan
  • Gilles Pilate
  • Annabelle Déjardin
  • Markus RüggebergEmail author
Original Article


Main conclusion

CAD-deficient poplars enabled studying the influence of altered lignin composition on mechanical properties. Severe alterations in lignin composition did not influence the mechanical properties.

Wood represents a hierarchical fiber-composite material with excellent mechanical properties. Despite its wide use and versatility, its mechanical behavior has not been entirely understood. It has especially been challenging to unravel the mechanical function of the cell wall matrix. Lignin engineering has been a useful tool to increase the knowledge on the mechanical function of lignin as it allows for modifications of lignin content and composition and the subsequent studying of the mechanical properties of these transgenics. Hereby, in most cases, both lignin composition and content are altered and the specific influence of lignin composition has hardly been revealed. Here, we have performed a comprehensive micromechanical, structural, and spectroscopic analysis on xylem strips of transgenic poplar plants, which are downregulated for cinnamyl alcohol dehydrogenase (CAD) by a hairpin-RNA-mediated silencing approach. All parameters were evaluated on the same samples. Raman microscopy revealed that the lignin of the hpCAD poplars was significantly enriched in aldehydes and reduced in the (relative) amount of G-units. FTIR spectra indicated pronounced changes in lignin composition, whereas lignin content was not significantly changed between WT and the hpCAD poplars. Microfibril angles were in the range of 18°–24° and were not significantly different between WT and transgenics. No significant changes were observed in mechanical properties, such as tensile stiffness, ultimate stress, and yield stress. The specific findings on hpCAD poplar allowed studying the specific influence of lignin composition on mechanics. It can be concluded that the changes in lignin composition in hpCAD poplars did not affect the micromechanical tensile properties.


Plant cell wall Cell wall mechanics Genetic modification Lignin composition 



This work was supported by Grants from the Agency for Innovation by Science and Technology (IWT) through the SBO project BIOLEUM (Grant no. 130039) and the SBO-FISH project ARBOREF (Grant no. 140894), and the European Framework Project MultiBioPro (project number: 311804). R. V. is indebted to the Research Foundation Flanders for a postdoctoral fellowship. N. G. acknowledges funding by the Austrian Science Fund (START-project SURFINPLANT Y-728-316) and the European community (ERC-consolidator grant SCATAPNUT 681885).

Compliance with ethical standards

Conflict of interest

The authors declare that they have no conflict of interest.

Supplementary material

425_2017_2828_MOESM1_ESM.pdf (419 kb)
Supplementary material 1 (PDF 419 kb)


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Copyright information

© Springer-Verlag GmbH Germany, part of Springer Nature 2017

Authors and Affiliations

  • Merve Özparpucu
    • 1
  • Notburga Gierlinger
    • 3
  • Ingo Burgert
    • 1
    • 2
  • Rebecca Van Acker
    • 4
    • 5
  • Ruben Vanholme
    • 4
    • 5
  • Wout Boerjan
    • 4
    • 5
  • Gilles Pilate
    • 6
  • Annabelle Déjardin
    • 6
  • Markus Rüggeberg
    • 1
    • 2
    Email author
  1. 1.Institute for Building Materials (IfB)ETH ZurichZurichSwitzerland
  2. 2.Laboratory of Applied Wood MaterialsEMPADübendorfSwitzerland
  3. 3.Institute for BiophysicsUniversity of Natural Resources and Life Sciences ViennaViennaAustria
  4. 4.Department of Plant Biotechnology and BioinformaticsGhent UniversityGhentBelgium
  5. 5.VIB Center for Plant Systems BiologyGhentBelgium
  6. 6.AGPF, INRAOrléansFrance

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