Ultrastructure and Mechanical Properties of Populus Wood with Reduced Lignin Content Caused by Transgenic Down-Regulation of Cinnamate 4-Hydroxylase
2010 (English)In: Biomacromolecules, ISSN 1525-7797, E-ISSN 1526-4602, Vol. 11, no 9, 2359-2365 p.Article in journal (Refereed) Published
Several key enzymes in lignin biosynthesis of Populus have been down-regulated by transgenie approaches to investigate their role in wood lignification and to explore their potential for lignin modification. Cinnamate 4-hydroxylase is an enzyme in the early phenylpropanoid pathway that has not yet been functionally analyzed in Populus. This study shows that down-regulation of cinnamate 4-hydroxylase reduced Klason lignin content by 30% with no significant change in syringyl to guaiacyl ratio. The lignin reduction resulted in ultrastructural differences of the wood and a 10% decrease in wood density. Mechanical properties investigated by tensile tests and dynamic mechanical analysis showed a decrease in stiffness, which could be explained by the lower density. The study demonstrates that a large modification in lignin content only has minor influences on tensile properties of wood in its axial direction and highlights the usefulness of wood modified beyond its natural variation by transgene technology in exploring the impact of wood biopolymer composition and ultrastructure on its material properties.
Place, publisher, year, edition, pages
2010. Vol. 11, no 9, 2359-2365 p.
Axial direction, Cinnamate 4-hydroxylase, Down-regulation, Guaiacyl, Key enzymes, Klason lignin, Lignin biosynthesis, Lignin contents, Lignin modifications, Lower density, Material property, Natural variation, Phenylpropanoid pathways, Populus, Tensile tests, Transgene, Transgenic approaches, Transgenics, Wood density, Biochemistry, Density (specific gravity), Dynamic analysis, Dynamic mechanical analysis, Enzymes, Lignin, Plants (botany), Stiffness, Tensile testing, Wood
IdentifiersURN: urn:nbn:se:kth:diva-26700DOI: 10.1021/bm100487eISI: 000281629600023ScopusID: 2-s2.0-77956536493OAI: oai:DiVA.org:kth-26700DiVA: diva2:372928
QC 201011292010-11-292010-11-262011-04-20Bibliographically approved