Red xylem and higher lignin extractability by down-regulating a cinnamyl alcohol dehydrogenase in poplar

Cinnamyl alcohol dehydrogenase (CAD) catalyzes the last step in the biosynthesis of the lignin precursors, the monolignols. We have down-regulated CAD in transgenic poplar (Populus tremula X Populus alba) by both antisense and co-suppression strategies. Several antisense and sense CAD transgenic pop...

Full description

Saved in:
Bibliographic Details
Published in:Plant physiology (Bethesda) 1996-12, Vol.112 (4), p.1479-1490
Main Authors: Marie Baucher, Chabbert, Brigitte, Pilate, Gilles, Van Doorsselaere, Jan, Marie-Thérèse Tollier, Michel Petit-Conil, Daniel Cornu, Bernard Monties, Van Montagu, Marc, Inzé, Dirk, Lise Jouanin, Boerjan, Wout
Format: Article
Language:English
Subjects:
acidificacion
acidification
actividad enzimatica
activite enzymatique
adn
Agronomy. Soil science and plant productions
alcohol dehydrogenase
alcohol deshidrogenasa
Alcohols
alcool deshydrogenase
Aldehydes
alkali treatment
Alkalies
biochemical pathways
Biological and medical sciences
biosintesis
biosynthese
biosynthesis
bois
cell walls
chemical composition
color
Colors
colour
composicion quimica
composition chimique
couleur
Dehydrogenases
dna
elaboracion de pulpa
enzymic activity
Fundamental and applied biological sciences. Psychology
Gene Regulation and Molecular Genetics
genetic transformation
Genetics and breeding of economic plants
hibridos
hybride
hybrids
Lignin
ligninas
lignine
lignins
madera
pared celular
paroi cellulaire
plantas transgenicas
plante transgenique
Plants
populus
Pulping
reduction en pate
traitement aux alcalis
transcripcion
transcription
transformacion genetica
transformation genetique
Transgenic plants
tratamiento alcalino
Varietal selection. Specialized plant breeding, plant breeding aims
via bioquimica del metabolismo
voie biochimique du metabolisme
wood
xilema
Xylem
xyleme
Yield, quality, earliness, varia
Citations: Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Cinnamyl alcohol dehydrogenase (CAD) catalyzes the last step in the biosynthesis of the lignin precursors, the monolignols. We have down-regulated CAD in transgenic poplar (Populus tremula X Populus alba) by both antisense and co-suppression strategies. Several antisense and sense CAD transgenic poplars had an approximately 70% reduced CAD activity that was associated with a red coloration of the xylem tissue. Neither the lignin amount nor the lignin monomeric composition (syringyl/guaiacyl) were significantly modified. However, phloroglucinol-HCl staining was different in the down-regulated CAD plants, suggesting changes in the number of aldehyde units in the lignin. Furthermore, the reactivity of the cell wall toward alkali treatment was altered: a lower amount of lignin was found in the insoluble, saponified residue and more lignin could be precipitated from the soluble alkali fraction. Moreover, large amounts of phenolic compounds, vanillin and especially syringaldehyde, were detected in the soluble alkali fraction of the CAD down-regulated poplars. Alkaline pulping experiments on 3-month-old trees showed a reduction of the kappa number without affecting the degree of cellulose degradation. These results indicate that reducing the CAD activity in trees might be a valuable strategy to optimize certain processes of the wood industry, especially those of the pulp and paper industry.
ISSN:0032-0889
1532-2548
DOI:10.1104/pp.112.4.1479