title: BcSAK1, a stress-activated mitogen-activated protein kinase, is involved in vegetative differentiation and pathogenicity in Botrytis cinerea.
abstract: The gene bcsak1, encoding a mitogen-activated protein kinase (MAPK) of Botrytis cinerea, was cloned and characterized. The protein has high homology to the yeast Hog1 and to corresponding MAPKs from filamentous fungi, but it shows unique functional features. The protein is phosphorylated under osmotic stress, specific fungicides, and oxidative stress mediated by H(2)O(2) and menadione. Northern blot analyses indicate that only a subset of typical oxidative stress response genes is regulated by BcSAK1. In contrast to most other fungal systems, Deltabcsak1 mutants are significantly impaired in vegetative and pathogenic development: they are blocked in conidia formation, show increased sclerotial development, and are unable to penetrate unwounded plant tissue. These data indicate that in B. cinerea the stress-activated MAPK cascade is involved in essential differentiation programs.
authors.affiliation: Institut für Botanik, Westf. Wilhelms-Universität, Schlossgarten 3, D-48149 Münster, Germany.
authors.forename: Nadja
authors.initials: N
authors.lastname: Segmüller
authors.forename: Ursula
authors.initials: U
authors.lastname: Ellendorf
authors.forename: Bettina
authors.initials: B
authors.lastname: Tudzynski
authors.forename: Paul
authors.initials: P
authors.lastname: Tudzynski
mesh_terms: D000933:Antifibrinolytic Agents / Q000494:pharmacology; D015152:Blotting, Northern; D020171:Botrytis / Q000254:growth & development* / Q000472:pathogenicity*; D002454:Cell Differentiation; D003001:Cloning, Molecular; D015966:Gene Expression Regulation, Fungal; D005816:Genetic Complementation Test; D006861:Hydrogen Peroxide / Q000494:pharmacology; D048055:Mitogen-Activated Protein Kinase 8 / Q000235:genetics / Q000378:metabolism*; D009997:Osmotic Pressure; D016877:Oxidants / Q000494:pharmacology; D018384:Oxidative Stress; D010766:Phosphorylation / Q000187:drug effects; D010802:Phylogeny; D014774:Virulence / Q000187:drug effects; D024483:Vitamin K 3 / Q000494:pharmacology
chemical_list: D000933:Antifibrinolytic Agents; D016877:Oxidants; D024483:Vitamin K 3; D006861:Hydrogen Peroxide; D048055:Mitogen-Activated Protein Kinase 8