skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Time course field analysis of COMT-downregulated switchgrass: Lignification, recalcitrance, and rust susceptibility

Journal Article · · BioEnergy Research
 [1];  [1];  [2];  [3];  [4];  [4];  [3];  [4];  [2];  [2];  [1]
  1. Univ. of Tennessee, Knoxville, TN (United States); Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
  2. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Samuel Roberts Noble Foundation, Ardmore, OK (United States)
  3. Univ. of Tennessee, Knoxville, TN (United States)
  4. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Univ. of North Texas, Denton, TX (United States)
+ Show Author Affiliations

Modifying plant cell walls by manipulating lignin biosynthesis can improve biofuel yields from lignocellulosic crops. For example, transgenic switchgrass lines with downregulated expression of caffeic acid O-methyltransferase, a lignin biosynthetic enzyme, produce up to 38% more ethanol than controls. The aim of the present study was to understand cell wall lignification over the second and third growing seasons of COMT-downregulated field-grown switchgrass. COMT gene expression, lignification, and cell wall recalcitrance were assayed for two independent transgenic lines at monthly intervals. Switchgrass rust (Puccinia emaculata) incidence was also tracked across the seasons. Trends in lignification over time differed between the 2 years. In 2012, sampling was initiated in mid-growing season on reproductive-stage plants and there was little variation in the lignin content of all lines (COMT-downregulated and control) over time. COMT-downregulated lines maintained 11-16% less lignin, 33-40% lower S/G (syringyl-to-guaiacyl) ratios, and 15-42% higher sugar release relative to controls for all time points. In 2013, sampling was initiated earlier in the season on elongation-stage plants and the lignin content of all lines steadily increased over time, while sugar release expectedly decreased. S/G ratios increased in non-transgenic control plants as biomass accumulated over the season, while remaining relatively stable across the season in the COMT-downregulated lines. Differences in cell wall chemistry between transgenic and non-transgenic lines were not apparent until plants transitioned to reproductive growth in mid-season, after which the cell walls of COMT-downregulated plants exhibited phenotypes consistent with what was observed in 2012. There were no differences in rust damage between transgenics and controls at any time point. Finally, these results provide relevant fundamental insights into the process of lignification in a maturing field-grown biofuel feedstock with downregulated lignin biosynthesis.

Research Organization:
National Renewable Energy Laboratory (NREL), Golden, CO (United States)
Sponsoring Organization:
USDOE Office of Science (SC), Biological and Environmental Research (BER)
Grant/Contract Number:
AC36-08GO28308
OSTI ID:
1334241
Report Number(s):
NREL/JA-5100-66619
Journal Information:
BioEnergy Research, Vol. 9, Issue 4; ISSN 1939-1234
Publisher:
SpringerCopyright Statement
Country of Publication:
United States
Language:
English
Citation Metrics:
Cited by: 10 works
Citation information provided by
Web of Science

References (50)

Cellulosic Biofuels journal June 2009
Feedstocks for Lignocellulosic Biofuels journal August 2010
Managing and enhancing switchgrass as a bioenergy feedstock journal November 2008
Ethanol yields and cell wall properties in divergently bred switchgrass genotypes journal October 2011
Genetic manipulation of lignin reduces recalcitrance and improves ethanol production from switchgrass journal February 2011
Functional characterization of the switchgrass (Panicum virgatum) R2R3-MYB transcription factor PvMYB4 for improvement of lignocellulosic feedstocks journal October 2011
Enhanced characteristics of genetically modified switchgrass (Panicum virgatum L.) for high biofuel production journal January 2013
Silencing of 4-coumarate:coenzyme A ligase in switchgrass leads to reduced lignin content and improved fermentable sugar yields for biofuel production journal July 2011
Downregulation of Cinnamyl-Alcohol Dehydrogenase in Switchgrass by RNA Silencing Results in Enhanced Glucose Release after Cellulase Treatment journal January 2011
Cell-wall carbohydrates and their modification as a resource for biofuels journal May 2008
Abiotic and Biotic Stresses and Changes in the Lignin Content and Composition in Plants journal April 2010
The role of the secondary cell wall in plant resistance to pathogens journal August 2014
Investigating plant cell wall components that affect biomass recalcitrance in poplar and switchgrass journal January 2013
Biomass pretreatment: Fundamentals toward application journal November 2011
Methods for Pretreatment of Lignocellulosic Biomass for Efficient Hydrolysis and Biofuel Production
  • Kumar, Parveen; Barrett, Diane M.; Delwiche, Michael J.
  • Industrial & Engineering Chemistry Research, Vol. 48, Issue 8, p. 3713-3729 https://doi.org/10.1021/ie801542g
journal April 2009
Altered lignin biosynthesis using biotechnology to improve lignocellulosic biofuel feedstocks journal July 2014
Genetic manipulation of lignocellulosic biomass for bioenergy journal December 2015
Developmental Control of Lignification in Stems of Lowland Switchgrass Variety Alamo and the Effects on Saccharification Efficiency journal October 2009
Standardization of Switchgrass Sample Collection for Cell Wall and Biomass Trait Analysis journal January 2013
How Do Lignin Composition, Structure, and Cross-Linking Affect Degradability? A Review of Cell Wall Model Studies journal January 2005
Relationship of growth cessation with the formation of diferulate cross-links and p -coumaroylated lignins in tall fescue leaf blades journal September 2002
Maize stem tissues: ferulate deposition in developing internode cell walls journal July 2003
Lignin Deposition and Associated Changes in Anatomy, Enzyme Activity, Gene Expression, and Ruminal Degradability in Stems of Tall Fescue at Different Developmental Stages journal September 2002
Maize Stem Tissues journal January 2006
Chemical composition and response to dilute-acid pretreatment and enzymatic saccharification of alfalfa, reed canarygrass, and switchgrass journal October 2006
Two-year field analysis of reduced recalcitrance transgenic switchgrass journal April 2014
Describing and Quantifying Growth Stages of Perennial Forage Grasses journal January 1991
High-Throughput Screening of Plant Cell-Wall Composition Using Pyrolysis Molecular Beam Mass Spectroscopy book January 2009
Reducing the Effect of Variable Starch Levels in Biomass Recalcitrance Screening book January 2012
ORIGINAL RESEARCH: Lignocellulose recalcitrance screening by integrated high-throughput hydrothermal pretreatment and enzymatic saccharification journal April 2010
New routes for lignin biosynthesis defined by biochemical characterization of recombinant ferulate 5-hydroxylase, a multifunctional cytochrome P450-dependent monooxygenase journal August 1999
Structure-Function Analyses of a Caffeic Acid O -Methyltransferase from Perennial Ryegrass Reveal the Molecular Basis for Substrate Preference journal December 2010
Coniferyl aldehyde 5-hydroxylation and methylation direct syringyl lignin biosynthesis in angiosperms journal August 1999
Downregulation of Caffeic Acid 3- O -Methyltransferase and Caffeoyl CoA 3- O -Methyltransferase in Transgenic Alfalfa: Impacts on Lignin Structure and Implications for the Biosynthesis of G and S Lignin journal January 2001
Genetic background impacts soluble and cell wall-bound aromatics in brown midrib mutants of sorghum journal September 2008
The brown midrib3 (bm3) mutation in maize occurs in the gene encoding caffeic acid O-methyltransferase. journal April 1995
Gene expression profiling and silencing reveal that monolignol biosynthesis plays a critical role in penetration defence in wheat against powdery mildew invasion journal January 2009
Cell Wall Metabolism in Response to Abiotic Stress journal February 2015
Can genetic engineering of lignin deposition be accomplished without an unacceptable yield penalty? journal April 2013
Field Evaluation of Transgenic Switchgrass Plants Overexpressing PvMYB4 for Reduced Biomass Recalcitrance journal January 2015
RNA interference suppression of lignin biosynthesis increases fermentable sugar yields for biofuel production from field-grown sugarcane journal April 2013
Genetic and molecular basis of grass cell-wall degradability. I. Lignin–cell wall matrix interactions journal May 2004
Hydroxycinnamates in lignification journal August 2009
Monitoring switchgrass composition to optimize harvesting periods for bioenergy and value-added products journal September 2013
Development of switchgrass (Panicum virgatum) as a bioenergy feedstock in the United States journal June 2005
Biomass Yield and Biofuel Quality of Switchgrass Harvested in Fall or Spring journal January 2006
Effects of altered lignin biosynthesis on phenylpropanoid metabolism and plant stress journal November 2013
Altering the Cell Wall and Its Impact on Plant Disease: From Forage to Bioenergy journal August 2014
Characterization of the Rust Fungus, Puccinia emaculata, and Evaluation of Genetic Variability for Rust Resistance in Switchgrass Populations journal October 2012
First Report of Rust on Switchgrass ( Panicum virgatum ) Caused by Puccinia emaculata in Tennessee journal December 2008

Cited By (5)

Study of traits and recalcitrance reduction of field-grown COMT down-regulated switchgrass journal January 2017
Development and use of a switchgrass (Panicum virgatum L.) transformation pipeline by the BioEnergy Science Center to evaluate plants for reduced cell wall recalcitrance journal December 2017
Low Lignin Mutants and Reduction of Lignin Content in Grasses for Increased Utilisation of Lignocellulose journal May 2019
Effects of field-grown transgenic switchgrass carbon inputs on soil organic carbon cycling journal January 2019
Simultaneous Downregulation of MTHFR and COMT in Switchgrass Affects Plant Performance and Induces Lesion-Mimic Cell Death journal June 2017

Figures / Tables (9)

Fig. 1(p. 23)figure Fig. 1
Fig. 2(p. 24)figure Fig. 2
Fig. 3(p. 25)figure Fig. 3
Fig. 4(p. 27)figure Fig. 4
Fig. 5(p. 29)figure Fig. 5
Table 1(p. 31)table Table 1
Fig. 1(p. 32)figure Fig. 1
Table 1(p. 34)table Table 1
Table 2(p. 35)table Table 2

Similar Records

Silencing Folylpolyglutamate Synthetase1 (FPGS1) in Switchgrass (Panicum virgatum L.) Improves Lignocellulosic Biofuel Production
Journal Article · Fri Jun 19 00:00:00 EDT 2020 · Frontiers in Plant Science · OSTI ID:1334241
+15 more
Hybridization of downregulated-COMT transgenic switchgrass lines with field-selected switchgrass for improved biomass traits
Journal Article · Thu Jan 21 00:00:00 EST 2016 · Euphytica · OSTI ID:1334241
+8 more
Simultaneous Downregulation of MTHFR and COMT in Switchgrass Affects Plant Performance and Induces Lesion-Mimic Cell Death
Journal Article · Tue Jun 20 00:00:00 EDT 2017 · Frontiers in Plant Science · OSTI ID:1334241
+4 more

Related Subjects

09 BIOMASS FUELS
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
biomass
caffeic acid O-methyltransferase (COMT)
lignin
lignocellulosic biofuel
switchgrass