title: Gene expression profiling of the nitrogen starvation stress response in the mycorrhizal ascomycete Tuber borchii.
abstract: The focus of this work is on the nitrogen starvation stress responses operating in a plant symbiotic fungus. A cDNA array profiling analysis was conducted on N-limited mycelia of the mycorrhizal ascomycete Tuber borchii. Fifty-one unique transcripts, out of 2062 redundant arrayed cDNAs, were differentially expressed by at least 1.5-fold in response to N deprivation. Only two N assimilation components-a nitrate transporter and a high-affinity ammonium transporter-were found among differentially expressed genes. All the other N status responsive genes code for as yet unidentified hypothetical proteins or components not directly involved in N assimilation or metabolism, especially carbohydrate binding proteins and oligosaccharide as well as lipid modifying enzymes. A subset of cDNA array data were confirmed and extended by Northern blot analysis, which showed that most of the latter components respond not only to nitrogen, but also to carbon source depletion.
authors.affiliation: Dipartimento di Biochimica e Biologia Molecolare, Università di Parma, Italy.
authors.forename: Barbara
authors.initials: B
authors.lastname: Montanini
authors.forename: Silvia
authors.initials: S
authors.lastname: Gabella
authors.forename: Simona
authors.initials: S
authors.lastname: Abbà
authors.forename: Martina
authors.initials: M
authors.lastname: Peter
authors.forename: Annegret
authors.initials: A
authors.lastname: Kohler
authors.forename: Paola
authors.initials: P
authors.lastname: Bonfante
authors.forename: Michel
authors.initials: M
authors.lastname: Chalot
authors.forename: Francis
authors.initials: F
authors.lastname: Martin
authors.forename: Simone
authors.initials: S
authors.lastname: Ottonello
mesh_terms: D000595:Amino Acid Sequence; D000596:Amino Acids / Q000378:metabolism; D001203:Ascomycota / Q000235:genetics* / Q000378:metabolism; D001483:Base Sequence; D050260:Carbohydrate Metabolism / Q000235:genetics; D005656:Fungal Proteins / Q000235:genetics*; D020869:Gene Expression Profiling; D015966:Gene Expression Regulation, Fungal; D050356:Lipid Metabolism / Q000235:genetics; D008969:Molecular Sequence Data; D009584:Nitrogen / Q000378:metabolism*; D020411:Oligonucleotide Array Sequence Analysis; D011401:Promoter Regions, Genetic / Q000235:genetics
chemical_list: D000596:Amino Acids; D005656:Fungal Proteins; D009584:Nitrogen