Plant Physiol. Journal of Pharmacology and Experimental Therapeutics
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH
QUICK SEARCH:   [advanced]


     

Plant Physiology Preview
Published on April 22, 2009; 10.1104/pp.109.137059

This Article
Right arrow Full Text (Plant Physiology Preview (PDF))
Right arrow Supplemental Data
Right arrow All Versions of this Article:
150/2/621    most recent
pp.109.137059v1
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in Web of Science
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via CrossRef
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Stewart, J. J.
Right arrow Articles by Mansfield, S. D.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Stewart, J. J.
Right arrow Articles by Mansfield, S. D.
Agricola
Right arrow Articles by Stewart, J. J.
Right arrow Articles by Mansfield, S. D.

Received February 17, 2009
Accepted April 20, 2009

The Effects on Lignin Structure of Over-Expression of Ferulate 5-Hydroxylase in Hybrid Poplar

Jaclyn J. Stewart , Takuya Akiyama , Clint C. Chapple , John Ralph , and Shawn D. Mansfield *

Department of Wood Science, University of British Columbia, Vancouver, BC, Canada; Department of Biochemistry, and Great Lakes Bioenergy Research Center, University of Wisconsin, Madison, Wisconsin, USA.; Department of Biochemistry, Purdue University, West Lafayette, Indiana, USA

* Corresponding author; email: shawnman{at}interchange.ubc.ca.

Poplar lignins with exceedingly high syringyl monomer levels are produced by over-expression of the ferulate 5-hydroxlase (F5H) gene driven by a cinnamate 4-hydroxylase (C4H) promoter. Compositional data derived from both standard degradative methods and NMR analyses of the entire lignin component (as well as isolated lignin fraction) indicated that the C4H::F5H transgenic lignin was comprised of as much as 97.5% syringyl units (derived from sinapyl alcohol), the remainder being guaiacyl units (derived from coniferyl alcohol); the syringyl level in the wild-type control was 68%. The resultant transgenic lignins are more linear, and display a lower degree of polymerization. Although the crucial {beta}-ether content is similar, the distribution of other inter-unit linkages in the lignin polymer is markedly different, with higher resinol ({beta}–{beta}) and spirodienone ({beta}–1) contents, but with virtually no phenylcoumarans ({beta}–5, which can only be formed from guaiacyl units). p-Hydroxybenzoates, acylating the {gamma}-positions of lignin sidechains, were reduced by over 50%, suggesting consequent impacts on related pathways. A model depicting the putative structure of the transgenic lignin resulting from the over-expression of F5H is presented. The altered structural features in the transgenic lignin polymer, as revealed here, support the contention that there are significant opportunities to improve biomass utilization by exploiting the malleability of plant lignification processes.






HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH
ASPB Publications PLANT PHYSIOLOGY® THE PLANT CELL
Copyright © 2009 by the American Society of Plant Biologists