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

Title: Downregulation of GAUT12 in Populus deltoides by RNA silencing results in reduced recalcitrance, increased growth and reduced xylan and pectin in a woody biofuel feedstock

Abstract

The inherent recalcitrance of woody bioenergy feedstocks is a major challenge for their use as a source of second-generation biofuel. Secondary cell walls that constitute the majority of hardwood biomass are rich in cellulose, xylan, and lignin. The interactions among these polymers prevent facile accessibility and deconstruction by enzymes and chemicals. Plant biomass that can with minimal pretreatment be degraded into sugars is required to produce renewable biofuels in a cost-effective manner. The following are the results: GAUT12/IRX8 is a putative glycosyltransferase proposed to be involved in secondary cell wall glucuronoxylan and/or pectin biosynthesis based on concomitant reductions of both xylan and the pectin homogalacturonan (HG) in Arabidopsis irx8 mutants. Two GAUT12 homologs exist in Populus trichocarpa, PtGAUT12.1 and PtGAUT12.2. Knockdown expression of both genes simultaneously has been shown to reduce xylan content in Populus wood. We tested the proposition that RNA interference (RNAi) downregulation of GAUT12.1 alone would lead to increased sugar release in Populus wood, that is, reduced recalcitrance, based on the hypothesis that GAUT12 synthesizes a wall structure required for deposition of xylan and that cell walls with less xylan and/or modified cell wall architecture would have reduced recalcitrance. Using an RNAi approach, we generated 11 Populusmore » deltoides transgenic lines with 50 to 67% reduced PdGAUT12.1 transcript expression compared to wild type (WT) and vector controls. Ten of the eleven RNAi lines yielded 4 to 8% greater glucose release upon enzymatic saccharification than the controls. The PdGAUT12.1 knockdown (PdGAUT12.1-KD) lines also displayed 12 to 52% and 12 to 44% increased plant height and radial stem diameter, respectively, compared to the controls. Knockdown of PdGAUT12.1 resulted in a 25 to 47% reduction in galacturonic acid and 17 to 30% reduction in xylose without affecting total lignin content, revealing that in Populus wood as in Arabidopsis, GAUT12 affects both pectin and xylan formation. Finally, analyses of the sugars present in sequential cell wall extracts revealed a reduction of glucuronoxylan and pectic HG and rhamnogalacturonan in extracts from PdGAUT12.1-KD lines.« less

Authors:
 [1];  [1];  [1];  [2];  [3];  [3];  [1];  [4];  [1];  [1];  [1];  [5];  [5];  [5];  [5];  [6];  [5];  [5];  [1];  [1]
  1. Univ. of Georgia, Athens, GA (United States); Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
  2. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
  3. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); ArborGen Inc., Ridgeville, SC (United States)
  4. Univ. of Georgia, Athens, GA (United States). Dept. of Plant Biology
  5. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); National Renewable Energy Lab. (NREL), Golden, CO (United States)
  6. Univ. of Georgia, Athens, GA (United States)
Publication Date:
Research Org.:
National Renewable Energy Lab. (NREL), Golden, CO (United States); Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Biological and Environmental Research (BER) (SC-23)
OSTI Identifier:
1220619
Alternate Identifier(s):
OSTI ID: 1265706
Report Number(s):
NREL/JA-2700-62639
Journal ID: ISSN 1754-6834
Grant/Contract Number:  
PS02-06ER64304; FG02-93ER20097; AC05-00OR22725
Resource Type:
Journal Article: Accepted Manuscript
Journal Name:
Biotechnology for Biofuels
Additional Journal Information:
Journal Volume: 8; Journal ID: ISSN 1754-6834
Publisher:
BioMed Central
Country of Publication:
United States
Language:
English
Subject:
09 BIOMASS FUELS; 59 BASIC BIOLOGICAL SCIENCES; biofuels; growth; pectin; Populus; saccharification; secondary cell wall; xylan; wood development

Citation Formats

Biswal, Ajaya K., Hao, Zhangying, Pattathil, Sivakumar, Yang, Xiaohan, Winkeler, Kim, Collins, Cassandra, Mohanty, Sushree S., Richardson, Elizabeth A., Gelineo-Albersheim, Ivana, Hunt, Kimberly, Ryno, David, Sykes, Robert W., Turner, Geoffrey B., Ziebell, Angela, Gjersing, Erica, Lukowitz, Wolfgang, Davis, Mark F., Decker, Stephen R., Hahn, Michael G., and Mohnen, Debra. Downregulation of GAUT12 in Populus deltoides by RNA silencing results in reduced recalcitrance, increased growth and reduced xylan and pectin in a woody biofuel feedstock. United States: N. p., 2015. Web. doi:10.1186/s13068-015-0218-y.
Biswal, Ajaya K., Hao, Zhangying, Pattathil, Sivakumar, Yang, Xiaohan, Winkeler, Kim, Collins, Cassandra, Mohanty, Sushree S., Richardson, Elizabeth A., Gelineo-Albersheim, Ivana, Hunt, Kimberly, Ryno, David, Sykes, Robert W., Turner, Geoffrey B., Ziebell, Angela, Gjersing, Erica, Lukowitz, Wolfgang, Davis, Mark F., Decker, Stephen R., Hahn, Michael G., & Mohnen, Debra. Downregulation of GAUT12 in Populus deltoides by RNA silencing results in reduced recalcitrance, increased growth and reduced xylan and pectin in a woody biofuel feedstock. United States. doi:10.1186/s13068-015-0218-y.
Biswal, Ajaya K., Hao, Zhangying, Pattathil, Sivakumar, Yang, Xiaohan, Winkeler, Kim, Collins, Cassandra, Mohanty, Sushree S., Richardson, Elizabeth A., Gelineo-Albersheim, Ivana, Hunt, Kimberly, Ryno, David, Sykes, Robert W., Turner, Geoffrey B., Ziebell, Angela, Gjersing, Erica, Lukowitz, Wolfgang, Davis, Mark F., Decker, Stephen R., Hahn, Michael G., and Mohnen, Debra. Thu . "Downregulation of GAUT12 in Populus deltoides by RNA silencing results in reduced recalcitrance, increased growth and reduced xylan and pectin in a woody biofuel feedstock". United States. doi:10.1186/s13068-015-0218-y. https://www.osti.gov/servlets/purl/1220619.
@article{osti_1220619,
title = {Downregulation of GAUT12 in Populus deltoides by RNA silencing results in reduced recalcitrance, increased growth and reduced xylan and pectin in a woody biofuel feedstock},
author = {Biswal, Ajaya K. and Hao, Zhangying and Pattathil, Sivakumar and Yang, Xiaohan and Winkeler, Kim and Collins, Cassandra and Mohanty, Sushree S. and Richardson, Elizabeth A. and Gelineo-Albersheim, Ivana and Hunt, Kimberly and Ryno, David and Sykes, Robert W. and Turner, Geoffrey B. and Ziebell, Angela and Gjersing, Erica and Lukowitz, Wolfgang and Davis, Mark F. and Decker, Stephen R. and Hahn, Michael G. and Mohnen, Debra},
abstractNote = {The inherent recalcitrance of woody bioenergy feedstocks is a major challenge for their use as a source of second-generation biofuel. Secondary cell walls that constitute the majority of hardwood biomass are rich in cellulose, xylan, and lignin. The interactions among these polymers prevent facile accessibility and deconstruction by enzymes and chemicals. Plant biomass that can with minimal pretreatment be degraded into sugars is required to produce renewable biofuels in a cost-effective manner. The following are the results: GAUT12/IRX8 is a putative glycosyltransferase proposed to be involved in secondary cell wall glucuronoxylan and/or pectin biosynthesis based on concomitant reductions of both xylan and the pectin homogalacturonan (HG) in Arabidopsis irx8 mutants. Two GAUT12 homologs exist in Populus trichocarpa, PtGAUT12.1 and PtGAUT12.2. Knockdown expression of both genes simultaneously has been shown to reduce xylan content in Populus wood. We tested the proposition that RNA interference (RNAi) downregulation of GAUT12.1 alone would lead to increased sugar release in Populus wood, that is, reduced recalcitrance, based on the hypothesis that GAUT12 synthesizes a wall structure required for deposition of xylan and that cell walls with less xylan and/or modified cell wall architecture would have reduced recalcitrance. Using an RNAi approach, we generated 11 Populus deltoides transgenic lines with 50 to 67% reduced PdGAUT12.1 transcript expression compared to wild type (WT) and vector controls. Ten of the eleven RNAi lines yielded 4 to 8% greater glucose release upon enzymatic saccharification than the controls. The PdGAUT12.1 knockdown (PdGAUT12.1-KD) lines also displayed 12 to 52% and 12 to 44% increased plant height and radial stem diameter, respectively, compared to the controls. Knockdown of PdGAUT12.1 resulted in a 25 to 47% reduction in galacturonic acid and 17 to 30% reduction in xylose without affecting total lignin content, revealing that in Populus wood as in Arabidopsis, GAUT12 affects both pectin and xylan formation. Finally, analyses of the sugars present in sequential cell wall extracts revealed a reduction of glucuronoxylan and pectic HG and rhamnogalacturonan in extracts from PdGAUT12.1-KD lines.},
doi = {10.1186/s13068-015-0218-y},
journal = {Biotechnology for Biofuels},
number = ,
volume = 8,
place = {United States},
year = {Thu Mar 12 00:00:00 EDT 2015},
month = {Thu Mar 12 00:00:00 EDT 2015}
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record

Citation Metrics:
Cited by: 27 works
Citation information provided by
Web of Science

Save / Share:

Works referenced in this record:

Feedstocks for Lignocellulosic Biofuels
journal, August 2010

  • Somerville, Cris; Youngs, Heather; Taylor, Caroline
  • Science, Vol. 329, Issue 5993, p. 790-792
  • DOI: 10.1126/science.1189268

Xylooligomers are strong inhibitors of cellulose hydrolysis by enzymes
journal, December 2010


A Comprehensive Toolkit of Plant Cell Wall Glycan-Directed Monoclonal Antibodies
journal, April 2010

  • Pattathil, S.; Avci, U.; Baldwin, D.
  • Plant Physiology, Vol. 153, Issue 2, p. 514-525
  • DOI: 10.1104/pp.109.151985

Engineering of plants with improved properties as biofuels feedstocks by vessel-specific complementation of xylan biosynthesis mutants
journal, January 2012

  • Petersen, Pia Damm; Lau, Jane; Ebert, Berit
  • Biotechnology for Biofuels, Vol. 5, Issue 1, Article No. 84
  • DOI: 10.1186/1754-6834-5-84

Biomass Recalcitrance: Engineering Plants and Enzymes for Biofuels Production
journal, February 2007

  • Himmel, M. E.; Ding, S.-Y.; Johnson, D. K.
  • Science, Vol. 315, Issue 5813, p. 804-807
  • DOI: 10.1126/science.1137016

Recent progress in consolidated bioprocessing
journal, June 2012

  • Olson, Daniel G.; McBride, John E.; Joe Shaw, A.
  • Current Opinion in Biotechnology, Vol. 23, Issue 3, p. 396-405
  • DOI: 10.1016/j.copbio.2011.11.026

A simple and rapid method for the permethylation of carbohydrates
journal, August 1984


Floral dip: a simplified method for Agrobacterium-mediated transformation of Arabidopsis thaliana
journal, December 1998


Functional identification of an Arabidopsis pectin biosynthetic homogalacturonan galacturonosyltransferase
journal, March 2006

  • Sterling, J. D.; Atmodjo, M. A.; Inwood, S. E.
  • Proceedings of the National Academy of Sciences, Vol. 103, Issue 13, p. 5236-5241
  • DOI: 10.1073/pnas.0600120103