title: Global gene expression during nitrogen starvation in the rice blast fungus, Magnaporthe grisea.
abstract: Efficient regulation of nitrogen metabolism likely plays a role in the ability of fungi to exploit ecological niches. To learn about regulation of nitrogen metabolism in the rice blast pathogen Magnaporthe grisea, we undertook a genome-wide analysis of gene expression under nitrogen-limiting conditions. Five hundred and twenty genes showed increased transcript levels at 12 and 48 h after shifting the fungus to media lacking nitrate as a nitrogen source. Thirty-nine of these genes have putative functions in amino acid metabolism and uptake, and include the global nitrogen regulator in M. grisea, NUT1. Evaluation of seven nitrogen starvation-induced genes revealed that all were expressed during rice infection. Targeted gene replacement on one such gene, the vacuolar serine protease, SPM1, resulted in decreased sporulation and appressorial development as well as a greatly attenuated ability to cause disease. Data are discussed in the context of nitrogen metabolism under starvation conditions, as well as conditions potentially encountered during invasive growth in planta.
authors.affiliation: North Carolina State University, Center for Integrated Fungal Research, Raleigh, USA.
authors.forename: N M
authors.initials: NM
authors.lastname: Donofrio
authors.forename: Y
authors.initials: Y
authors.lastname: Oh
authors.forename: R
authors.initials: R
authors.lastname: Lundy
authors.forename: H
authors.initials: H
authors.lastname: Pan
authors.forename: D E
authors.initials: DE
authors.lastname: Brown
authors.forename: J S
authors.initials: JS
authors.lastname: Jeong
authors.forename: S
authors.initials: S
authors.lastname: Coughlan
authors.forename: T K
authors.initials: TK
authors.lastname: Mitchell
authors.forename: R A
authors.initials: RA
authors.lastname: Dean
mesh_terms: D000596:Amino Acids / Q000378:metabolism; D001665:Binding Sites; D001692:Biological Transport / Q000235:genetics; D004268:DNA-Binding Proteins / Q000235:genetics; D050980:GATA Transcription Factors / Q000378:metabolism; D015870:Gene Expression; D015966:Gene Expression Regulation, Fungal; D005800:Genes, Fungal; D020082:Magnaporthe / Q000235:genetics* / Q000472:pathogenicity; D009584:Nitrogen / Q000378:metabolism*; D020411:Oligonucleotide Array Sequence Analysis; D012275:Oryza / Q000378:metabolism / Q000382:microbiology*; D010935:Plant Diseases / Q000382:microbiology*; D011401:Promoter Regions, Genetic; D012697:Serine Endopeptidases / Q000235:genetics
chemical_list: D000596:Amino Acids; D004268:DNA-Binding Proteins; D050980:GATA Transcription Factors; D012697:Serine Endopeptidases; D009584:Nitrogen