title: Sugar transporters in the black truffle Tuber melanosporum: from gene prediction to functional characterization.
abstract: In a natural forest ecosystem, ectomycorrhiza formation is a way for soil fungi to obtain carbohydrates from their host plants. However, our knowledge of sugar transporters in ectomycorrhizal ascomycetous fungi is limited. To bridge this gap we used data obtained from the sequenced genome of the ectomycorrhizal fungus Tuber melanosporum Vittad. to search for sugar transporters. Twenty-three potential hexose transporters were found, and three of them (Tmelhxt1, Tmel2281 and Tmel131), differentially expressed during the fungus life cycle, were investigated. The heterologous expression of Tmelhxt1 and Tmel2281 in an hxt-null Saccharomyces cerevisiae strain restores the growth in glucose and fructose. The functional characterization and expression profiles of Tmelhxt1 and Tmel2281 in the symbiotic phase suggest that they are high affinity hexose transporters at the plant-fungus interface. On the contrary, Tmel131 is preferentially expressed in the fruiting body and its inability to restore the S. cerevisiae mutant strain growth led us to hypothesize that it could be involved in the transport of alternative carbon sources important for a hypothetical saprophytic strategy for the complete maturation of the carpophore.
authors.affiliation: DISB Department of Biomolecular Sciences, University of Urbino Carlo Bo, 61029 Urbino, Italy. Electronic address: paola.ceccaroli@uniurb.it.
authors.forename: Paola
authors.initials: P
authors.lastname: Ceccaroli
authors.affiliation: DISB Department of Biomolecular Sciences, University of Urbino Carlo Bo, 61029 Urbino, Italy. Electronic address: roberta.saltarelli@uniurb.it.
authors.forename: Roberta
authors.initials: R
authors.lastname: Saltarelli
authors.affiliation: DISB Department of Biomolecular Sciences, University of Urbino Carlo Bo, 61029 Urbino, Italy. Electronic address: emanuela.polidori@uniurb.it.
authors.forename: Emanuela
authors.initials: E
authors.lastname: Polidori
authors.affiliation: DISB Department of Biomolecular Sciences, University of Urbino Carlo Bo, 61029 Urbino, Italy. Electronic address: elena.barbieri@uniurb.it.
authors.forename: Elena
authors.initials: E
authors.lastname: Barbieri
authors.affiliation: DISB Department of Biomolecular Sciences, University of Urbino Carlo Bo, 61029 Urbino, Italy. Electronic address: michele.guescini@uniurb.it.
authors.forename: Michele
authors.initials: M
authors.lastname: Guescini
authors.affiliation: DISTEVA Department of Earth, Life and Environmental Sciences, University of Urbino Carlo Bo, 61029 Urbino, Italy. Electronic address: caterina.ciacci@uniurb.it.
authors.forename: Caterina
authors.initials: C
authors.lastname: Ciacci
authors.affiliation: DISB Department of Biomolecular Sciences, University of Urbino Carlo Bo, 61029 Urbino, Italy. Electronic address: vilberto.stocchi@uniurb.it.
authors.forename: Vilberto
authors.initials: V
authors.lastname: Stocchi
mesh_terms: D001203:Ascomycota / Q000235:genetics* / Q000378:metabolism*; D001692:Biological Transport; D050260:Carbohydrate Metabolism; D003001:Cloning, Molecular; D019295:Computational Biology; D003470:Culture Media / Q000737:chemistry; D005632:Fructose / Q000378:metabolism; D015870:Gene Expression; D005947:Glucose / Q000378:metabolism; D026901:Membrane Transport Proteins / Q000235:genetics* / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000254:growth & development / Q000378:metabolism
chemical_list: D003470:Culture Media; D026901:Membrane Transport Proteins; D005632:Fructose; D005947:Glucose
keywords: Ascomycetes; Ectomycorrhiza; Fungi; Sugar transporters; Tuber melanosporum