title: A Mutant of the Bck1 Homolog from Cryphonectria parasitica Resulted in Sectorization with an Impaired Pathogenicity.
abstract: CpBck1, an ortholog of the cell-wall integrity mitogen-activated protein kinase kinase kinase of Saccharomyces cerevisiae, was cloned and characterized from the chestnut blight fungus Cryphonectria parasitica. The CpBck1-null mutant displayed cell wall integrity-related phenotypic changes such as abnormal cell morphology and wall formation and hypersensitivity to cell wall-disrupting agents. In addition, the mutant showed severely retarded growth without any sign of normal development, such as hyphal differentiation, conidiation, or pigmentation. As the culture proceeded, the mutant colony showed sporadic sectorization. Once sectored, the sectored phenotype of robust mycelial growth without differentiation was stably inherited. Compared with the wild type, both the parental CpBck1-null mutant and the sectored progeny exhibited marked impaired virulence. The present study revealed that a mutation in a signaling pathway component related to cell-wall integrity resulted in sporadic sectorization and these sectored phenotypes were stably inherited, suggesting that this signal transduction pathway is implicated in adaptive genetic changes for sectorization.
authors.affiliation: 1 Department of Bio-Environmental Chemistry, Institute of Life Science and Natural Resources, Wonkwang University, Iksan, Chonbuk 570-749, Korea;
authors.forename: Jung-Mi
authors.initials: JM
authors.lastname: Kim
authors.affiliation: 2 Institute for Molecular Biology and Genetics, Center for Fungal Pathogenesis, Department of Bioactive Material Sciences, Chonbuk National University, Jeonju, Chonbuk 561-756, Korea; and.
authors.forename: Joong-Gi
authors.initials: JG
authors.lastname: Lee
authors.affiliation: 2 Institute for Molecular Biology and Genetics, Center for Fungal Pathogenesis, Department of Bioactive Material Sciences, Chonbuk National University, Jeonju, Chonbuk 561-756, Korea; and.
authors.forename: Suk-Hyun
authors.initials: SH
authors.lastname: Yun
authors.affiliation: 2 Institute for Molecular Biology and Genetics, Center for Fungal Pathogenesis, Department of Bioactive Material Sciences, Chonbuk National University, Jeonju, Chonbuk 561-756, Korea; and.
authors.forename: Kum-Kang
authors.initials: KK
authors.lastname: So
authors.affiliation: 2 Institute for Molecular Biology and Genetics, Center for Fungal Pathogenesis, Department of Bioactive Material Sciences, Chonbuk National University, Jeonju, Chonbuk 561-756, Korea; and.
authors.forename: Yo-Han
authors.initials: YH
authors.lastname: Ko
authors.affiliation: 3 Department of Agricultural Biotechnology, Seoul National University, Seoul 151-921, Korea.
authors.forename: Young Ho
authors.initials: YH
authors.lastname: Kim
authors.affiliation: 2 Institute for Molecular Biology and Genetics, Center for Fungal Pathogenesis, Department of Bioactive Material Sciences, Chonbuk National University, Jeonju, Chonbuk 561-756, Korea; and.
authors.forename: Seung-Moon
authors.initials: SM
authors.lastname: Park
authors.affiliation: 2 Institute for Molecular Biology and Genetics, Center for Fungal Pathogenesis, Department of Bioactive Material Sciences, Chonbuk National University, Jeonju, Chonbuk 561-756, Korea; and.
authors.forename: Dae-Hyuk
authors.initials: DH
authors.lastname: Kim
mesh_terms: D001203:Ascomycota / Q000235:genetics* / Q000472:pathogenicity / Q000648:ultrastructure; D002473:Cell Wall / Q000378:metabolism; D031256:Eleocharis / Q000276:immunology / Q000382:microbiology*; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism; D015966:Gene Expression Regulation, Fungal; D025301:Hyphae; D020930:MAP Kinase Kinase Kinases / Q000235:genetics* / Q000378:metabolism; D010641:Phenotype; D024301:Plant Bark / Q000276:immunology / Q000382:microbiology; D010935:Plant Diseases / Q000276:immunology / Q000382:microbiology*; D017422:Sequence Analysis, DNA; D017384:Sequence Deletion; D015398:Signal Transduction; D014774:Virulence
chemical_list: D005656:Fungal Proteins; D020930:MAP Kinase Kinase Kinases