Variation in Cell Wall Composition among Forage Maize (Zea mays L.) Inbred Lines and Its Impact on Digestibility:  Analysis of Neutral Detergent Fiber Composition by Pyrolysis-Gas Chromatography-Mass Spectrometry

Abstract

Cell wall digestibility is an important determinant of forage quality, but the relationship between cell wall composition and digestibility is poorly understood. We analyzed the neutral detergent fiber (NDF) fraction of nine maize inbred lines and one brown midrib3 mutant with pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS). Among 29 pyrolysis fragments that were quantified, two carbohydrate-derived and six lignin-derived fragments showed statistically significant genetic variation. The pyrolysis products 4-vinyl phenol and 2,6-dimethoxy-4-vinyl phenol were negatively correlated with digestibility, whereas furfural and 3-(4-hydroxyphenyl)-3-oxopropanal showed a positive correlation with digestibility. Linear discriminant analysis of the pyrolysis data resulted in the resolution of groups of inbred lines with different digestibility properties based on their chemical composition. These analyses reveal that digestibility is governed by complex interactions between different cell wall compounds, but that several pyrolysis fragments can be used as markers to distinguish between maize lines with different digestibility.

Wood Based Lignin Reactions Important to the Biorefinery and Pulp and Paper Industries

“…It has been speculated that when guaiacyl type of lignin is present, a thinner cell wall is formed and it is easier to degrade. The same was found in a similar study by Fontaine et al (2003), and they sustained the hypothesis that a thinner cell wall contained more guaiacyl lignin than a thicker cell wall.…”

Extent of genotypic variation for maize cell wall bioconversion traits across environments and among hybrid combinations

“…As expected, among cell wall components, variation was highest for Lig and Lig/CW (CV G = 16 %), but also for DHS (CV G = 8 %). These observations reinforce the notion that natural diversity in the biochemical composition of the maize cell wall and its physical properties is primarily ascribed to variation in the balance, monomeric makeup and ultra-structure of non-cellulosic cell wall polymers (Fontaine et al 2003;Barriere et al 2008;Torres et al 2013Torres et al , 2015. In this context and concurrent with previous studies (Lorenzana et al 2010;Torres et al 2013Torres et al , 2015, correlation analyses confirm that the extent of enzymatic depolymerization (GluCon) of maize biomass is strongly, and negatively associated (r [ -0.75) to the concentration of cell wall phenolics (Lig, Lig/CW), and positively impacted (r = 0.85) by increments in the degree of substitution (DHS) of cell wall glucuronoarabinoxylans.…”

Genetic and genomic approaches for improving biofuel production from maize

“…Genetic variation for phenolic components in the grass cell wall and relationships with its degradability Genetic variation for lignin content, lignin monomeric composition and/or p-hydroxycinnamate contents has already been shown in previous investigations in maize (Dhillon et al 1990;Lundvall et al 1994;Méchin et al 2000;Fontaine et al 2003aFontaine et al , 2003bFrey et al 2004;Riboulet et al 2008). Complementarily, a comparison of lines done at Lusignan in 2006 illustrates nearly the greatest known variation for each cell wall related trait in early and medium early maize (Table 1).…”