title: Range of cell-wall alterations enhance saccharification in Brachypodium distachyon mutants.
abstract: Lignocellulosic plant biomass is an attractive feedstock for the production of sustainable biofuels, but the commercialization of such products is hampered by the high costs of processing this material into fermentable sugars (saccharification). One approach to lowering these costs is to produce crops with cell walls that are more susceptible to hydrolysis to reduce preprocessing and enzyme inputs. To deepen our understanding of the molecular genetic basis of lignocellulose recalcitrance, we have screened a mutagenized population of the model grass Brachypodium distachyon for improved saccharification with an industrial polysaccharide-degrading enzyme mixture. From an initial screen of 2,400 M2 plants, we selected 12 lines that showed heritable improvements in saccharification, mostly with no significant reduction in plant size or stem strength. Characterization of these putative mutants revealed a variety of alterations in cell-wall components. We have mapped the underlying genetic lesions responsible for increased saccharification using a deep sequencing approach, and here we report the mapping of one of the causal mutations to a narrow region in chromosome 2. The most likely candidate gene in this region encodes a GT61 glycosyltransferase, which has been implicated in arabinoxylan substitution. Our work shows that forward genetic screening provides a powerful route to identify factors that impact on lignocellulose digestibility, with implications for improving feedstock for cellulosic biofuel production.
authors.affiliation: Centre for Novel Agricultural Products, Department of Biology, University of York, Heslington, York YO10 5DD, United Kingdom;
authors.forename: Poppy E
authors.initials: PE
authors.lastname: Marriott
authors.affiliation: Institut National de la Recherche Agronomique and AgroParisTech, Institut Jean-Pierre Bourgin, Unité Mixte de Recherche 1318, Équipes de Recherche Labellisées Centre National de la Recherche Scientifique 3559, Saclay Plant Sciences, RD10, F-78026 Versailles, France; and.
authors.forename: Richard
authors.initials: R
authors.lastname: Sibout
authors.affiliation: Institut National de la Recherche Agronomique and AgroParisTech, Institut Jean-Pierre Bourgin, Unité Mixte de Recherche 1318, Équipes de Recherche Labellisées Centre National de la Recherche Scientifique 3559, Saclay Plant Sciences, RD10, F-78026 Versailles, France; and.
authors.forename: Catherine
authors.initials: C
authors.lastname: Lapierre
authors.affiliation: Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, DK-1871 Copenhagen, Denmark.
authors.forename: Jonatan U
authors.initials: JU
authors.lastname: Fangel
authors.affiliation: Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, DK-1871 Copenhagen, Denmark.
authors.forename: William G T
authors.initials: WG
authors.lastname: Willats
authors.affiliation: Institut National de la Recherche Agronomique and AgroParisTech, Institut Jean-Pierre Bourgin, Unité Mixte de Recherche 1318, Équipes de Recherche Labellisées Centre National de la Recherche Scientifique 3559, Saclay Plant Sciences, RD10, F-78026 Versailles, France; and.
authors.forename: Herman
authors.initials: H
authors.lastname: Hofte
authors.affiliation: Centre for Novel Agricultural Products, Department of Biology, University of York, Heslington, York YO10 5DD, United Kingdom;
authors.forename: Leonardo D
authors.initials: LD
authors.lastname: Gómez
authors.affiliation: Centre for Novel Agricultural Products, Department of Biology, University of York, Heslington, York YO10 5DD, United Kingdom; sjmm1@york.ac.uk.
authors.forename: Simon J
authors.initials: SJ
authors.lastname: McQueen-Mason
mesh_terms: D056804:Biofuels; D018533:Biomass; D058431:Brachypodium / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism*; D050260:Carbohydrate Metabolism; D002473:Cell Wall / Q000378:metabolism*; D002482:Cellulose / Q000378:metabolism; D002874:Chromosome Mapping; D032461:Chromosomes, Plant / Q000235:genetics; D016695:Glycosyltransferases / Q000235:genetics / Q000378:metabolism; D008031:Lignin / Q000378:metabolism; D009005:Monosaccharides / Q000378:metabolism; D009154:Mutation; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D018547:Plant Stems / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D011134:Polysaccharides / Q000378:metabolism; D025341:Principal Component Analysis; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D056804:Biofuels; D009005:Monosaccharides; D010940:Plant Proteins; D011134:Polysaccharides; C036909:lignocellulose; D002482:Cellulose; D008031:Lignin; D016695:Glycosyltransferases
keywords: feruloylation; lignin; lignocellulosic biofuel; matrix polysaccharides