title: Phylogenetic, genomic organization and expression analysis of hydrophobin genes in the ectomycorrhizal basidiomycete Laccaria bicolor.
abstract: Hydrophobins are morphogenetic, small secreted hydrophobic fungal proteins produced in response to changing development and environmental conditions. These proteins are important in the interaction between certain fungi and their hosts. In mutualistic ectomycorrhizal fungi several hydrophobins form a subclass of mycorrhizal-induced small secreted proteins that are likely to be critical in the formation of the symbiotic interface with host root cells. In this study, two genomes of the ectomycorrhizal basidiomycete Laccaria bicolor strains S238N-H82 (from North America) and 81306 (from Europe) were surveyed to construct a comprehensive genome-wide inventory of hydrophobins and to explore their characteristics and roles during host colonization. The S238N-H82 L. bicolor hydrophobin gene family is composed of 12 genes while the 81306 strain encodes nine hydrophobins, all corresponding to class I hydrophobins. The three extra hydrophobin genes encoded by the S238N-H82 genome likely arose via gene duplication and are bordered by transposon rich regions. Expression profiles of the hydrophobin genes of L. bicolor varied greatly depending on life stage (e.g. free living mycelium vs. root colonization) and on the host root environment. We conclude from this study that the complex diversity and range of expression profiles of the Laccaria hydrophobin multi-gene family have likely been a selective advantage for this mutualist in colonizing a wide range of host plants.
authors.affiliation: INRA, UMR 1136 INRA - University Henri Poincaré, Interactions Arbres/Microorganismes, INRA-Nancy, 54280 Champenoux, France. jm.plett@nancy.inra.fr
authors.forename: Jonathan M
authors.initials: JM
authors.lastname: Plett
authors.forename: Julien
authors.initials: J
authors.lastname: Gibon
authors.forename: Annegret
authors.initials: A
authors.lastname: Kohler
authors.forename: Kecia
authors.initials: K
authors.lastname: Duffy
authors.forename: Patrik J
authors.initials: PJ
authors.lastname: Hoegger
authors.forename: Rajesh
authors.initials: R
authors.lastname: Velagapudi
authors.forename: James
authors.initials: J
authors.lastname: Han
authors.forename: Ursula
authors.initials: U
authors.lastname: Kües
authors.forename: Igor V
authors.initials: IV
authors.lastname: Grigoriev
authors.forename: Francis
authors.initials: F
authors.lastname: Martin
mesh_terms: D000595:Amino Acid Sequence; D005656:Fungal Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental; D015966:Gene Expression Regulation, Fungal; D016681:Genome, Fungal; D055399:Laccaria / Q000145:classification* / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D008969:Molecular Sequence Data; D005810:Multigene Family; D038821:Mycorrhizae / Q000145:classification* / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D010802:Phylogeny; D016415:Sequence Alignment
chemical_list: D005656:Fungal Proteins