title: The genome of Xylona heveae provides a window into fungal endophytism.
abstract: Xylona heveae has only been isolated as an endophyte of rubber trees. In an effort to understand the genetic basis of endophytism, we compared the genome contents of X. heveae and 36 other Ascomycota with diverse lifestyles and nutritional modes. We focused on genes that are known to be important in the host-fungus interaction interface and that presumably have a role in determining the lifestyle of a fungus. We used phylogenomic data to infer the higher-level phylogenetic position of the Xylonomycetes, and mined ITS sequences to explore its taxonomic and ecological diversity. The X. heveae genome contains a low number of enzymes needed for plant cell wall degradation, suggesting that Xylona is a highly adapted specialist and likely dependent on its host for survival. The reduced repertoire of carbohydrate active enzymes could reflect an adaptation to intercellulary growth and to the avoidance of the host's immune system, suggesting that Xylona has a strictly endophytic lifestyle. Phylogenomic data resolved the position of Xylonomycetes as sister to Lecanoromycetes and Eurotiomycetes and placed the beetle-endosymbiont Symbiotaphrina as a member of this class. ITS data revealed that Trinosporium is also part of the Xylonomycetes, extending the taxonomic and ecological diversity of this group.
authors.affiliation: Clark University, Biology Department, 950 Main Street, Worcester, MA 01610, USA. Electronic address: rgazis@clarku.edu.
authors.forename: Romina
authors.initials: R
authors.lastname: Gazis
authors.affiliation: US Department of Energy Joint Genome Institute, 2800 Mitchell Drive, Walnut Creek, CA 94598, USA.
authors.forename: Alan
authors.initials: A
authors.lastname: Kuo
authors.affiliation: US Department of Energy Joint Genome Institute, 2800 Mitchell Drive, Walnut Creek, CA 94598, USA.
authors.forename: Robert
authors.initials: R
authors.lastname: Riley
authors.affiliation: US Department of Energy Joint Genome Institute, 2800 Mitchell Drive, Walnut Creek, CA 94598, USA.
authors.forename: Kurt
authors.initials: K
authors.lastname: LaButti
authors.affiliation: US Department of Energy Joint Genome Institute, 2800 Mitchell Drive, Walnut Creek, CA 94598, USA.
authors.forename: Anna
authors.initials: A
authors.lastname: Lipzen
authors.affiliation: US Department of Energy Joint Genome Institute, 2800 Mitchell Drive, Walnut Creek, CA 94598, USA.
authors.forename: Junyan
authors.initials: J
authors.lastname: Lin
authors.affiliation: US Department of Energy Joint Genome Institute, 2800 Mitchell Drive, Walnut Creek, CA 94598, USA.
authors.forename: Mojgan
authors.initials: M
authors.lastname: Amirebrahimi
authors.affiliation: Oregon State University, Department of Botany and Plant Pathology, Corvallis, OR 97331, USA; Los Alamos National Laboratory, Bioscience Division, Los Alamos, NM, USA.
authors.forename: Cedar N
authors.initials: CN
authors.lastname: Hesse
authors.affiliation: Oregon State University, Department of Botany and Plant Pathology, Corvallis, OR 97331, USA.
authors.forename: Joseph W
authors.initials: JW
authors.lastname: Spatafora
authors.affiliation: Aix-Marseille Université, CNRS, UMR 7257, Marseille, France; Aix-Marseille Université, Architecture et Fonction des Macromolécules Biologiques, 13288 Marseille cedex 9, France; King Abdulaziz University, Department of Biological Sciences, Jeddah 21589, Saudi Arabia.
authors.forename: Bernard
authors.initials: B
authors.lastname: Henrissat
authors.affiliation: Aix-Marseille Université, CNRS, UMR 7257, Marseille, France.
authors.forename: Matthieu
authors.initials: M
authors.lastname: Hainaut
authors.affiliation: US Department of Energy Joint Genome Institute, 2800 Mitchell Drive, Walnut Creek, CA 94598, USA.
authors.forename: Igor V
authors.initials: IV
authors.lastname: Grigoriev
authors.affiliation: Clark University, Biology Department, 950 Main Street, Worcester, MA 01610, USA.
authors.forename: David S
authors.initials: DS
authors.lastname: Hibbett
mesh_terms: D001203:Ascomycota / Q000145:classification / Q000235:genetics* / Q000502:physiology; D004271:DNA, Fungal / Q000235:genetics; D021903:DNA, Ribosomal Spacer / Q000235:genetics; D060026:Endophytes / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification / Q000502:physiology; D016681:Genome, Fungal; D028482:Hevea / Q000382:microbiology*; D008969:Molecular Sequence Data; D010802:Phylogeny
chemical_list: D004271:DNA, Fungal; D021903:DNA, Ribosomal Spacer
keywords: CAZymes; Glycoside hydrolases; Horizontally transmitted endophytes; Sapwood endophytes; Symbiotaphrina; Trinosporium