title: Dissecting the role of G-protein signalling in primary metabolism in the wheat pathogen Stagonospora nodorum.
abstract: Mutants of the wheat pathogenic fungus Stagonospora nodorum lacking G-protein subunits display a variety of phenotypes including melanization defects, primary metabolic changes and a decreased ability to sporulate. To better understand the causes of these phenotypes, Stagonospora nodorum strains lacking a Gα, Gβ or Gγ subunit were compared to a wild-type strain using metabolomics. Agar plate growth at 22 °C revealed a number of fundamental metabolic changes and highlighted the influential role of these proteins in glucose utilization. A further characterization of the mutants was undertaken during prolonged storage at 4 °C, conditions known to induce sporulation in these sporulation-deficient signalling mutants. The abundance of several compounds positively correlated with the onset of sporulation including the dissacharide trehalose, the tryptophan degradation product tryptamine and the secondary metabolite alternariol; metabolites all previously associated with sporulation. Several other compounds decreased or were absent during sporulation. The levels of one such compound (Unknown_35.27_2194_319) decreased from being one of the more abundant compounds to absence during pycnidial maturation. This study has shed light on the role of G-protein subunits in primary metabolism during vegetative growth and exploited the cold-induced sporulation phenomenon in these mutants to identify some key metabolic changes that occur during asexual reproduction.
authors.affiliation: Metabolomics Australia, Murdoch University, Perth 6150, WA, Australia.|Separation Science and Metabolomics Laboratory, Murdoch University, Perth 6150, WA, Australia.
authors.forename: Joel P A
authors.initials: JPA
authors.lastname: Gummer
authors.affiliation: Metabolomics Australia, Murdoch University, Perth 6150, WA, Australia.|Separation Science and Metabolomics Laboratory, Murdoch University, Perth 6150, WA, Australia.
authors.forename: Robert D
authors.initials: RD
authors.lastname: Trengove
authors.affiliation: Australian Centre for Necrotrophic Fungal Pathogens, Department of Environment and Agriculture, Curtin University, Perth 6102, WA, Australia.
authors.forename: Richard P
authors.initials: RP
authors.lastname: Oliver
authors.affiliation: Division of Plant Sciences, Research School of Biology, Australian National University, ACT 0200, Australia.
authors.forename: Peter S
authors.initials: PS
authors.lastname: Solomon
mesh_terms: D001203:Ascomycota / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism*; D019204:GTP-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D010935:Plant Diseases / Q000382:microbiology*; D021122:Protein Subunits / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction; D013172:Spores, Fungal / Q000201:enzymology / Q000254:growth & development / Q000378:metabolism; D014199:Trehalose / Q000378:metabolism; D014908:Triticum / Q000382:microbiology*; D014364:Tryptophan / Q000378:metabolism
chemical_list: D005656:Fungal Proteins; D021122:Protein Subunits; D014364:Tryptophan; D014199:Trehalose; D019204:GTP-Binding Proteins