Effects of Increased Nitrogen Supply on the Lignification of Poplar Wood

Abstract

The short-term influence of adequate and high nitrogen fertilization on poplar lignification was investigated. The high nitrogen supply decreased lignin staining in the newly formed secondary xylem, indicating that lignin deposition was affected. Acetyl bromide determinations gave a 9-10% decrease in lignin content; however, Klason lignin content was unchanged. Thioacidolysis showed that elevated N supply affected lignin structure such that there was a reduced frequency of lignin units involved in beta-O-4 bonds, a reduced syringyl/guaiacyl ratio, an increased frequency of p-hydroxyphenyl lignin units, more guaiacyl units with free phenolic groups, and more p-hydroxybenzoic acid ester-linked to poplar lignins. These features suggest that lignins from poplars grown under high N bear structural similarities to lignins formed during early stages of wood development. The findings also indicate that a gravitational stimulus inducing the formation of tension wood and high N availability lead to similar and additive effects on lignin content and structure.

N-fertilization has different effects on the growth, carbon and nitrogen physiology, and wood properties of slow- and fast-growing Populus species

“…N-fertilization tended to reduce lignin contents in wood of both species (Fig. 6), which is consistent with previous studies (Novaes et al ., 2009; Pitre et al ., 2007 a , b ). Lower lignin contents in the wood of N-fertilized poplars are advantageous for bioethanol production (Studer et al ., 2011) and are probably associated with the formation of a G-layer that is almost devoid of lignin (Pitre et al, 2007 b ).…”

“…For instance, both the lignin contents and the composition of syringyl and guaiacyl monomers can influence the suitability of wood for bioethanol production (Studer et al ., 2011). N-fertilization can alter the lignin contents and composition (Pitre et al ., 2007 b ; Luo and Polle, 2009). The caloric value of wood, which is determined by its chemical composition (Zhou et al ., 2011), is also responsive to N addition (Luo and Polle, 2009).…”

Investigation of tension wood formation and 2,6-dichlorbenzonitrile application in short rotation coppice willow composition and enzymatic saccharification

“…The 26-day treatment, although long enough to influence glucose release yields, was a comparatively short portion of the 91 days of total growth. More prolonged or acute tension wood induction has been shown to produce high-glucan, low-lignin phenotypes [18,25,26]. …”

Different Routes for Conifer- and Sinapaldehyde and Higher Saccharification upon Deficiency in the Dehydrogenase CAD1

“…The ASL was measured spectrophotometrically as described previously (Dence, 1992). Lignin composition was determined by thioacidolysis (Lapierre et al, 1999), and the frequency of free-phenolic end groups in lignin was determined by thioacidolysis after exhaustive phenol methylation of the samples with diazomethane (Pitre et al, 2007). The determination of p-hydroxybenzoate esters and other phenolics linked to poplar lignins was by mild alkaline hydrolysis according to a previously published procedure (Lapierre et al, 1999).…”