Structural Alterations of Lignins in Transgenic Poplars with Depressed Cinnamyl Alcohol Dehydrogenase or Caffeic Acid O-Methyltransferase Activity Have an Opposite Impact on the Efficiency of Industrial Kraft Pulping1
| Autor: | Michel Petit-Conil, Javier Romero, Lise Jouanin, Wout Boerjan, Valérie Ferret, Jean-Charles Leplé, Brigitte Pollet, Catherine Lapierre, Gilles Pilate, Véronique De Nadai, Gabriel Toval |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 1999 |
| Předmět: |
0106 biological sciences
Physiology Cinnamyl-alcohol dehydrogenase Ether Plant Science macromolecular substances 01 natural sciences Syringaldehyde complex mixtures 03 medical and health sciences chemistry.chemical_compound Caffeate O-methyltransferase Genetics Caffeic acid Lignin 030304 developmental biology 0303 health sciences Chemistry fungi technology industry and agriculture Xylem food and beverages Kraft process Biochemistry 010606 plant biology & botany Research Article |
| Popis: | We evaluated lignin profiles and pulping performances of 2-year-old transgenic poplar (Populus tremula × Populus alba) lines severely altered in the expression of caffeic acid/5-hydroxyferulic acidO-methyltransferase (COMT) or cinnamyl alcohol dehydrogenase (CAD). Transgenic poplars with CAD orCOMT antisense constructs showed growth similar to control trees. CAD down-regulated poplars displayed a red coloration mainly in the outer xylem. A 90% lower COMT activity did not change lignin content but dramatically increased the frequency of guaiacyl units and resistant biphenyl linkages in lignin. This alteration severely lowered the efficiency of kraft pulping. The Klason lignin level of CAD-transformed poplars was slightly lower than that of the control. Whereas CAD down-regulation did not change the frequency of labile ether bonds or guaiacyl units in lignin, it increased the proportion of syringaldehyde and diarylpropane structures and, more importantly with regard to kraft pulping, of free phenolic groups in lignin. In the most depressed line, ASCAD21, a substantially higher content in free phenolic units facilitated lignin solubilization and fragmentation during kraft pulping. These results point the way to genetic modification of lignin structure to improve wood quality for the pulp industry. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|