title: Analysis of a Modern Hybrid and an Ancient Sugarcane Implicates a Complex Interplay of Factors in Affecting Recalcitrance to Cellulosic Ethanol Production.
abstract: Abundant evidence exists to support a role for lignin as an important element in biomass recalcitrance. However, several independent studies have also shown that factors apart from lignin are also relevant and overall, the relative importance of different recalcitrance traits remains in dispute. In this study we used two genetically distant sugarcane genotypes, and performed a correlational study with the variation in anatomical parameters, cell wall composition, and recalcitrance factors between these genotypes. In addition we also tracked alterations in these characteristics in internodes at different stages of development. Significant differences in the development of the culm between the genotypes were associated with clear differential distributions of lignin content and composition that were not correlated with saccharification and fermentation yield. Given the strong influence of the environment on lignin content and composition, we hypothesized that sampling within a single plant could allow us to more easily interpret recalcitrance and changes in lignin biosynthesis than analysing variations between different genotypes with extensive changes in plant morphology and culm anatomy. The syringyl/guaiacyl (S/G) ratio was higher in the oldest internode of the modern genotype, but S/G ratio was not correlated with enzymatic hydrolysis yield nor fermentation efficiency. Curiously we observed a strong positive correlation between ferulate ester level and cellulose conversion efficiency. Together, these data support the hypothesis that biomass enzymatic hydrolysis recalcitrance is governed by a quantitative heritage rather than a single trait.
authors.affiliation: Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, Minas Gerais, Brazil.
authors.forename: Viviane
authors.initials: V
authors.lastname: Guzzo de Carli Poelking
authors.affiliation: Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, Minas Gerais, Brazil.
authors.forename: Andrea
authors.initials: A
authors.lastname: Giordano
authors.affiliation: Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, Minas Gerais, Brazil.
authors.forename: Maria Esther
authors.initials: ME
authors.lastname: Ricci-Silva
authors.affiliation: Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, Minas Gerais, Brazil.
authors.forename: Thomas Christopher
authors.initials: TC
authors.lastname: Rhys Williams
authors.affiliation: Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, Minas Gerais, Brazil.
authors.forename: Diego
authors.initials: D
authors.lastname: Alves Peçanha
authors.affiliation: Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, Minas Gerais, Brazil.
authors.forename: Marília
authors.initials: M
authors.lastname: Contin Ventrella
authors.affiliation: Biochemistry Department, and the Great Lakes Bioenergy Research Center, University of Wisconsin, Madison, Wisconsin, United States of America.
authors.forename: Jorge
authors.initials: J
authors.lastname: Rencoret
authors.affiliation: Biochemistry Department, and the Great Lakes Bioenergy Research Center, University of Wisconsin, Madison, Wisconsin, United States of America.
authors.forename: John
authors.initials: J
authors.lastname: Ralph
authors.affiliation: Departamento de Fitotecnia, Universidade Federal de Viçosa, Viçosa, Minas Gerais, Brazil.
authors.forename: Márcio Henrique
authors.initials: MH
authors.lastname: Pereira Barbosa
authors.affiliation: Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, Minas Gerais, Brazil.
authors.forename: Marcelo
authors.initials: M
authors.lastname: Loureiro
mesh_terms: D001709:Biotechnology / Q000379:methods*; D050260:Carbohydrate Metabolism; D002473:Cell Wall / Q000378:metabolism; D002482:Cellulose / Q000378:metabolism*; D004951:Esterification; D000431:Ethanol / Q000378:metabolism*; D005285:Fermentation; D005838:Genotype; D006824:Hybridization, Genetic; D006868:Hydrolysis; D008031:Lignin / Q000378:metabolism; D009682:Magnetic Resonance Spectroscopy; D018547:Plant Stems / Q000254:growth & development; D031786:Saccharum / Q000033:anatomy & histology / Q000235:genetics* / Q000254:growth & development; D014574:Uronic Acids / Q000378:metabolism; D014990:Xylans / Q000378:metabolism
chemical_list: D014574:Uronic Acids; D014990:Xylans; D000431:Ethanol; D002482:Cellulose; D008031:Lignin