title: Fungal variegatic acid and extracellular polysaccharides promote the site-specific generation of reactive oxygen species.
abstract: This study aims to clarify the role of variegatic acid (VA) in fungal attack by Serpula lacrymans, and also the generation and scavenging of reactive oxygen species (ROS) by the fungus. VA promotes a mediated Fenton reaction to generated ROS after oxalate solubilizes oxidized forms of iron. The fungal extracellular matrix (ECM) β-glucan scavenged ROS, and we propose this as a mechanism to protect the fungal hyphae while ROS generation is promoted to deconstruct the lignocellulose cell wall. A relatively high pH (4.4) also favored Fe(III) transfer from oxalate to VA as opposed to a lower pH (2.2) conditions, suggesting a pH-dependent Fe(III) transfer to VA employed by S. lacrymans. This permits ROS generation within the higher pH of the cell wall, while limiting ROS production near the fungal hyphae, while β-glucan from the fungal ECM scavenges ROS in the more acidic environments surrounding the fungal hyphae.
authors.affiliation: MOE Key Laboratory of Wooden Material Science and Application, Beijing Forestry University, Beijing, China.|Department of Sustainable Biomaterials, Virginia Tech, Blacksburg, VA, USA.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Zhu
authors.affiliation: Edward Via Virginia College of Osteopathic Medicine, Blacksburg, VA, USA.
authors.forename: James
authors.initials: J
authors.lastname: Mahaney
authors.affiliation: Center for Agriculture, Food and the Environment, 319 Stockbridge Hall, University of Massachusetts, Amherst, MA, USA.
authors.forename: Jody
authors.initials: J
authors.lastname: Jellison
authors.affiliation: MOE Key Laboratory of Wooden Material Science and Application, Beijing Forestry University, Beijing, China. caoj@bjfu.edu.cn.
authors.forename: Jinzhen
authors.initials: J
authors.lastname: Cao
authors.affiliation: Department of Pharmaceutical Microbiology at the Hans Knöll Institute, Friedrich-Schiller-Universität Jena, Jena, Germany.
authors.forename: Julia
authors.initials: J
authors.lastname: Gressler
authors.affiliation: Department of Pharmaceutical Microbiology at the Hans Knöll Institute, Friedrich-Schiller-Universität Jena, Jena, Germany.
authors.forename: Dirk
authors.initials: D
authors.lastname: Hoffmeister
authors.affiliation: Department of Sustainable Biomaterials, Virginia Tech, Blacksburg, VA, USA. Barry.Goodell@gmail.com.
authors.forename: Barry
authors.initials: B
authors.lastname: Goodell
mesh_terms: D001487:Basidiomycota / Q000378:metabolism*; D002264:Carboxylic Acids / Q000737:chemistry*; D002473:Cell Wall / Q000378:metabolism; D005290:Ferric Compounds / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D007501:Iron / Q000737:chemistry; D007783:Lactones / Q000737:chemistry*; D008031:Lignin / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism*; D047071:beta-Glucans / Q000378:metabolism*
chemical_list: D002264:Carboxylic Acids; D005290:Ferric Compounds; D007783:Lactones; D017382:Reactive Oxygen Species; D047071:beta-Glucans; C036909:lignocellulose; D008031:Lignin; D007501:Iron; C492654:pulvinic acid
keywords: Fe(III) reduction; Fungal extracellular matrix; Fungal sheath; Radical scavengers; Reactive oxygen species; Serpula lacrymans; Variegatic acid; β-Glucan