title: Inducibility studies with the arbuscular mycorrhizal fungus Glomus mosseae 3-phosphoglycerate kinase (PGK) gene promoter.
abstract: Arbuscular mycorrhizal (AM) fungi are a multifaceted group of mutualistic symbionts that are common to terrestrial ecosystems. The role of AM fungi within processes related to carbon (C) dynamics of the plant-root-soil system are of global significance. An understanding of the C metabolism of AM fungi within the symbiotic and asymbiotic stages of their lifecycle is a necessary pre-requisite to understanding the mechanisms of C movement. This investigation studies the regulation of the Glomus mosseae (Gm) 3-phosphoglycerate kinase ( PGK) gene promoter by different C sources. The suitability of studying the GmPGK promoter (P(GmPGK)) within Saccharomyces cerevisiae was confirmed by complementation of a S. cerevisiae pgk (-) mutant with an expression vector carrying the P(GmPGK) driving the expression of the S. cerevisiae PGK gene. The inducibility of the P(GmPGK) to different C sources was studied by creating a P(GmPGK)-luciferase fusion, which was introduced into a S. cerevisiae expression vector and used to transform S. cerevisiae. The P(GmPGK)-luciferase fusion was tested for expression within S. cerevisiae by RT-PCR analysis and was shown to be expressing the luciferase gene. C upshift studies were completed to evaluate the inducibility of this promoter by different C sources. The sources raffinose, glycerol and glucose significantly induced the P(GmPGK), whereas the sources galactose, succinate and sucrose had the lowest transcriptional responses. Semi-quantitative RT-PCR was used to establish gene expression patterns of GmPGK during spore germination; and up-regulation of the GmPGK gene was observed.
authors.affiliation: Plant Science Division, Scottish Agricultural College, Kings Buildings, West Mains Road, Edinburgh, EH9 3JG, UK. L.Harrier@ed.sac.ac.uk
authors.forename: Lucy A
authors.initials: LA
authors.lastname: Harrier
authors.forename: Linda J
authors.initials: LJ
authors.lastname: Paterson
mesh_terms: D002244:Carbon / Q000378:metabolism; D004790:Enzyme Induction; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism; D005658:Fungi / Q000201:enzymology / Q000235:genetics*; D015966:Gene Expression Regulation, Fungal; D005816:Genetic Complementation Test; D008156:Luciferases / Q000235:genetics; D009154:Mutation; D010735:Phosphoglycerate Kinase / Q000235:genetics* / Q000378:metabolism; D011401:Promoter Regions, Genetic; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics; D013172:Spores, Fungal / Q000502:physiology; D014158:Transcription, Genetic
chemical_list: D005656:Fungal Proteins; D011993:Recombinant Fusion Proteins; D002244:Carbon; D008156:Luciferases; D010735:Phosphoglycerate Kinase