title: The targeting of starch binding domains from starch synthase III to the cell wall alters cell wall composition and properties.
abstract: Starch binding domains of starch synthase III from Arabidopsis thaliana (SBD123) binds preferentially to cell wall polysaccharides rather than to starch in vitro. Transgenic plants overexpressing SBD123 in the cell wall are larger than wild type. Cell wall components are altered in transgenic plants. Transgenic plants are more susceptible to digestion than wild type and present higher released glucose content. Our results suggest that the transgenic plants have an advantage for the production of bioethanol in terms of saccharification of essential substrates. The plant cell wall, which represents a major source of biomass for biofuel production, is composed of cellulose, hemicelluloses, pectins and lignin. A potential biotechnological target for improving the production of biofuels is the modification of plant cell walls. This modification is achieved via several strategies, including, among others, altering biosynthetic pathways and modifying the associations and structures of various cell wall components. In this study, we modified the cell wall of A. thaliana by targeting the starch-binding domains of A. thaliana starch synthase III to this structure. The resulting transgenic plants (E8-SDB123) showed an increased biomass, higher levels of both fermentable sugars and hydrolyzed cellulose and altered cell wall properties such as higher laxity and degradability, which are valuable characteristics for the second-generation biofuels industry. The increased biomass and degradability phenotype of E8-SBD123 plants could be explained by the putative cell-wall loosening effect of the in tandem starch binding domains. Based on these results, our approach represents a promising biotechnological tool for reducing of biomass recalcitrance and therefore, the need for pretreatments.
authors: Facultad de Ciencias Bioquímicas y Farmacéuticas, Centro de Estudios Fotosintéticos y Bioquímicos - Consejo Nacional de Investigaciones Científicas y Técnicas (CEFOBI - CONICET), Universidad Nacional de Rosario, Rosario, Santa Fe, Argentina.
authors: Mauricio J
authors: MJ
authors: Grisolia
authors: Facultad de Ciencias Bioquímicas y Farmacéuticas, Centro de Estudios Fotosintéticos y Bioquímicos - Consejo Nacional de Investigaciones Científicas y Técnicas (CEFOBI - CONICET), Universidad Nacional de Rosario, Rosario, Santa Fe, Argentina.
authors: Diego A
authors: DA
authors: Peralta
authors: Instituto de Investigaciones Biotecnológicas - Instituto Tecnológico de Chascomús (IIB-INTECH), Universidad Nacional de San Martin, Chascomús, Buenos Aires, Argentina.|Centro de Investigación y Desarrollo en Fermentaciones Industriales (CINDEFI), 50 y 115, 1900, La Plata, Buenos Aires, Argentina.
authors: Hugo A
authors: HA
authors: Valdez
authors: Facultad de Ciencias Bioquímicas y Farmacéuticas, Centro de Estudios Fotosintéticos y Bioquímicos - Consejo Nacional de Investigaciones Científicas y Técnicas (CEFOBI - CONICET), Universidad Nacional de Rosario, Rosario, Santa Fe, Argentina.
authors: Julieta
authors: J
authors: Barchiesi
authors: Facultad de Ciencias Bioquímicas y Farmacéuticas, Centro de Estudios Fotosintéticos y Bioquímicos - Consejo Nacional de Investigaciones Científicas y Técnicas (CEFOBI - CONICET), Universidad Nacional de Rosario, Rosario, Santa Fe, Argentina.|Instituto de Investigaciones Biotecnológicas - Instituto Tecnológico de Chascomús (IIB-INTECH), Universidad Nacional de San Martin, Chascomús, Buenos Aires, Argentina.
authors: Diego F
authors: DF
authors: Gomez-Casati
authors: Facultad de Ciencias Bioquímicas y Farmacéuticas, Centro de Estudios Fotosintéticos y Bioquímicos - Consejo Nacional de Investigaciones Científicas y Técnicas (CEFOBI - CONICET), Universidad Nacional de Rosario, Rosario, Santa Fe, Argentina. busi@cefobi-conicet.gov.ar.|Instituto de Investigaciones Biotecnológicas - Instituto Tecnológico de Chascomús (IIB-INTECH), Universidad Nacional de San Martin, Chascomús, Buenos Aires, Argentina. busi@cefobi-conicet.gov.ar.
authors: María V
authors: MV
authors: Busi
mesh_terms: D029681:Arabidopsis Proteins / Q000737:chemistry* / Q000378:metabolism; D001665:Binding Sites; D056804:Biofuels; D002473:Cell Wall / Q000737:chemistry / Q000378:metabolism*; D005632:Fructose / Q000096:biosynthesis; D005690:Galactose / Q000096:biosynthesis; D005947:Glucose / Q000096:biosynthesis; D005964:Glucosyltransferases / Q000737:chemistry* / Q000378:metabolism; D030821:Plants, Genetically Modified; D011134:Polysaccharides / Q000378:metabolism; D013213:Starch / Q000378:metabolism*
chemical_list: D029681:Arabidopsis Proteins; D056804:Biofuels; D011134:Polysaccharides; D005632:Fructose; D013213:Starch; D005964:Glucosyltransferases; C504530:starch synthase III, Arabidopsis; D005947:Glucose; D005690:Galactose
keywords: Cell extension; Cell wall; Cell wall digestibility; Fermentable sugars; Starch binding domains