title: Cell wall targeted in planta iron accumulation enhances biomass conversion and seed iron concentration in Arabidopsis and rice.
abstract: Conversion of nongrain biomass into liquid fuel is a sustainable approach to energy demands as global population increases. Previously, we showed that iron can act as a catalyst to enhance the degradation of lignocellulosic biomass for biofuel production. However, direct addition of iron catalysts to biomass pretreatment is diffusion-limited, would increase the cost and complexity of biorefinery unit operations and may have deleterious environmental impacts. Here, we show a new strategy for in planta accumulation of iron throughout the volume of the cell wall where iron acts as a catalyst in the deconstruction of lignocellulosic biomass. We engineered CBM-IBP fusion polypeptides composed of a carbohydrate-binding module family 11 (CBM11) and an iron-binding peptide (IBP) for secretion into Arabidopsis and rice cell walls. CBM-IBP transformed Arabidopsis and rice plants show significant increases in iron accumulation and biomass conversion compared to respective controls. Further, CBM-IBP rice shows a 35% increase in seed iron concentration and a 40% increase in seed yield in greenhouse experiments. CBM-IBP rice potentially could be used to address iron deficiency, the most common and widespread nutritional disorder according to the World Health Organization.
authors.affiliation: Center for Direct Catalytic Conversion Of Biomass to Biofuels (C3Bio), Purdue University, West Lafayette, IN, USA.|Department of Horticulture, Purdue University, West Lafayette, IN, USA.|Department of Biological Sciences, Purdue University, West Lafayette, IN, USA.
authors.forename: Haibing
authors.initials: H
authors.lastname: Yang
authors.affiliation: Biosciences Center, National Renewable Energy Laboratory, Golden, CO, USA.
authors.forename: Hui
authors.initials: H
authors.lastname: Wei
authors.affiliation: Center for Direct Catalytic Conversion Of Biomass to Biofuels (C3Bio), Purdue University, West Lafayette, IN, USA.|Department of Horticulture, Purdue University, West Lafayette, IN, USA.
authors.forename: Guojie
authors.initials: G
authors.lastname: Ma
authors.affiliation: Center for Direct Catalytic Conversion Of Biomass to Biofuels (C3Bio), Purdue University, West Lafayette, IN, USA.|Department of Biological Sciences, Purdue University, West Lafayette, IN, USA.
authors.forename: Mauricio S
authors.initials: MS
authors.lastname: Antunes
authors.affiliation: X-ray Science Division, Advanced Photon Source, Argonne National Laboratory, Argonne, IL, USA.
authors.forename: Stefan
authors.initials: S
authors.lastname: Vogt
authors.affiliation: Center for Direct Catalytic Conversion Of Biomass to Biofuels (C3Bio), Purdue University, West Lafayette, IN, USA.|Department of Horticulture, Purdue University, West Lafayette, IN, USA.
authors.forename: Joseph
authors.initials: J
authors.lastname: Cox
authors.affiliation: Department of Horticulture, Purdue University, West Lafayette, IN, USA.
authors.forename: Xiao
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Center for Direct Catalytic Conversion Of Biomass to Biofuels (C3Bio), Purdue University, West Lafayette, IN, USA.|Department of Horticulture, Purdue University, West Lafayette, IN, USA.
authors.forename: Xiping
authors.initials: X
authors.lastname: Liu
authors.affiliation: National Bioenergy Center, National Renewable Energy Laboratory, Golden, CO, USA.
authors.forename: Lintao
authors.initials: L
authors.lastname: Bu
authors.affiliation: X-ray Science Division, Advanced Photon Source, Argonne National Laboratory, Argonne, IL, USA.
authors.forename: S Charlotte
authors.initials: SC
authors.lastname: Gleber
authors.affiliation: Department of Biological Sciences, Purdue University, West Lafayette, IN, USA.|Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN, USA.
authors.forename: Nicholas C
authors.initials: NC
authors.lastname: Carpita
authors.affiliation: Department of Bioengineering, Northeastern University, Boston, MA, USA.|Department of Chemistry and Chemical Biology, Northeastern University, Boston, MA, USA.
authors.forename: Lee
authors.initials: L
authors.lastname: Makowski
authors.affiliation: Biosciences Center, National Renewable Energy Laboratory, Golden, CO, USA.
authors.forename: Michael E
authors.initials: ME
authors.lastname: Himmel
authors.affiliation: X-ray Science Division, Advanced Photon Source, Argonne National Laboratory, Argonne, IL, USA.
authors.forename: Melvin P
authors.initials: MP
authors.lastname: Tucker
authors.affiliation: Center for Direct Catalytic Conversion Of Biomass to Biofuels (C3Bio), Purdue University, West Lafayette, IN, USA.|Department of Biological Sciences, Purdue University, West Lafayette, IN, USA.
authors.forename: Maureen C
authors.initials: MC
authors.lastname: McCann
authors.affiliation: Center for Direct Catalytic Conversion Of Biomass to Biofuels (C3Bio), Purdue University, West Lafayette, IN, USA. asmurphy@umd.edu.|Department of Horticulture, Purdue University, West Lafayette, IN, USA. asmurphy@umd.edu.|Department of Plant Science and Landscape Architecture, University of Maryland, College Park, MD, USA. asmurphy@umd.edu.
authors.forename: Angus S
authors.initials: AS
authors.lastname: Murphy
authors.affiliation: Center for Direct Catalytic Conversion Of Biomass to Biofuels (C3Bio), Purdue University, West Lafayette, IN, USA.|Department of Horticulture, Purdue University, West Lafayette, IN, USA.|Department of Plant Science and Landscape Architecture, University of Maryland, College Park, MD, USA.|Department of Environmental Science and Technology, University of Maryland, College Park, MD, USA.
authors.forename: Wendy A
authors.initials: WA
authors.lastname: Peer
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism*; D056804:Biofuels; D018533:Biomass; D002473:Cell Wall / Q000235:genetics / Q000378:metabolism*; D007501:Iron / Q000378:metabolism*; D012275:Oryza / Q000235:genetics / Q000378:metabolism*; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D012639:Seeds / Q000378:metabolism*
chemical_list: D056804:Biofuels; D010940:Plant Proteins; D007501:Iron
keywords: biofuel; carbohydrate-binding module; cell wall; iron concentration; iron-binding peptide; secretion