Signaling via the G protein alpha subunit FGA2 is necessary for pathogenesis in Fusarium oxysporum.
Cloning and disruption of fga1, the gene encoding the G protein alpha subunit FGA1 in phytopathogenic fungus Fusarium oxysporum, has been reported previously, and the fga1 disruptants showed altered colony morphology, increased heat resistance, reduced conidiation and pathogenicity. To further evaluate the role of G protein signaling in this fungus, cloning of fga2, which encodes the second Galpha protein FGA2, was performed by PCR methods. The deduced primary structure of FGA2 (355 amino acid residues) showed high identity with other Galpha proteins, which belong to class III of fungal Galpha proteins. Disruption of fga2 led to higher heat resistance, similar to the fga1 disruptants, but pathogenicity was completely lost, unlike the fga1 disruptants. Alteration of colony morphology and conidiation, which was observed in the fga1 disruptants, was not observed in the fga2 disruptants. The fga1/fga2 double disruptants showed phenotypic alterations similar to the fga1 or fga2 single disruptants, but increase of heat resistance was much more pronounced than in each single disruptant.
Jain
Sona
S
Faculty of Agriculture, Ehime University, Matsuyama, 790-8566, Japan.
Akiyama
Kouichi
K
Takata
Renkichi
R
Ohguchi
Tomizo
T
D000595:Amino Acid Sequence; D003001:Cloning, Molecular; D018553:Cucumis sativus / Q000382:microbiology*; D005670:Fusarium / Q000235:genetics / Q000254:growth & development / Q000472:pathogenicity* / Q000502:physiology; D044385:GTP-Binding Protein alpha Subunits / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D017353:Gene Deletion; D015966:Gene Expression Regulation, Fungal; D008969:Molecular Sequence Data; D010641:Phenotype; D010935:Plant Diseases / Q000382:microbiology; D018515:Plant Leaves / Q000382:microbiology; D015398:Signal Transduction
D044385:GTP-Binding Protein alpha Subunits