title: The small GTPase BcCdc42 affects nuclear division, germination and virulence of the gray mold fungus Botrytis cinerea.
abstract: The small GTPase Cdc42 plays a central role in various processes in eukaryotic cells including growth, differentiation and cytoskeleton organization. Whereas it is essential in the yeast Saccharomyces cerevisiae, its role in filamentous fungi differs, due to the complementing, partly overlapping function of Rac. We analyzed the role of the Cdc42 homologue in the necrotrophic, broad host range pathogen Botrytis cinerea. Deletion mutants of bccdc42 showed various growth abnormalities; the mutants had reduced growth rate and hyphal branching, they produced fewer conidia, which were enlarged and misshapen and had germination defects. Additionally, the mutants were impaired in sclerotia development. Cytological studies indicate that at least part of this phenotype could be attributed to disturbed control of nuclear division: conidia and hyphae of the mutant showed twofold higher nucleus/cytoplasm ratio compared to wild type cells. Apart from these effects on vegetative growth and differentiation, Δbccdc42 strains were attenuated in penetration and colonization of host tissue, confirming that BcCdc42 - though being not essential like in yeast - is involved in important developmental processes in B. cinerea.
authors.affiliation: Institut fuer Biologie und Biotechnologie der Pflanzen, Westfaelische Wilhelms-Universitaet Muenster, Hindenburgplatz 55, D-48149 Muenster, Germany.
authors.forename: Leonie
authors.initials: L
authors.lastname: Kokkelink
authors.forename: Anna
authors.initials: A
authors.lastname: Minz
authors.forename: Muhamad
authors.initials: M
authors.lastname: Al-Masri
authors.forename: Sabine
authors.initials: S
authors.lastname: Giesbert
authors.forename: Radwan
authors.initials: R
authors.lastname: Barakat
authors.forename: Amir
authors.initials: A
authors.lastname: Sharon
authors.forename: Paul
authors.initials: P
authors.lastname: Tudzynski
mesh_terms: D020171:Botrytis / Q000166:cytology / Q000254:growth & development / Q000472:pathogenicity / Q000502:physiology*; D048750:Cell Nucleus Division; D017353:Gene Deletion; D025301:Hyphae / Q000254:growth & development; D027805:Phaseolus / Q000382:microbiology; D010935:Plant Diseases / Q000382:microbiology; D013172:Spores, Fungal / Q000166:cytology; D014774:Virulence; D020764:cdc42 GTP-Binding Protein / Q000235:genetics / Q000378:metabolism*
chemical_list: D020764:cdc42 GTP-Binding Protein