Gene expression profiling of the nitrogen starvation stress response in the mycorrhizal ascomycete Tuber borchii.
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.
Montanini
Barbara
B
Dipartimento di Biochimica e Biologia Molecolare, Università di Parma, Italy.
Gabella
Silvia
S
Abbà
Simona
S
Peter
Martina
M
Kohler
Annegret
A
Bonfante
Paola
P
Chalot
Michel
M
Martin
Francis
F
Ottonello
Simone
S
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
D000596:Amino Acids; D005656:Fungal Proteins; D009584:Nitrogen