title: Germling fusion via conidial anastomosis tubes in the grey mould Botrytis cinerea requires NADPH oxidase activity.
abstract: In many filamentous ascomycete species, the early steps of colony development include fusion between germinating vegetative spores (conidial germlings). Often these fusion events are mediated by specialized hyphal structures, so-called conidial anastomosis tubes (CATs). Here, we show that germling fusion in the grey mould Botrytis cinerea is mediated by hyphal structures possessing the typical features of CATs. Formation of these structures is delayed when spores are germinating on complex media compared to growth on poor substrates. Fusion frequency is also influenced by the growth conditions of the precultures from which spores were obtained. During germination on hydrophobic plant surfaces, which induce pathogenic development, CAT formation is significantly suppressed. Screening of existing B. cinerea gene knockout mutants identified strains lacking the NADPH oxidase BcNoxA or the potential Nox regulator BcNoxR as fusion deficient, suggesting a potential role of reactive oxygen species (ROS) signalling in CAT formation and fusion.
authors.affiliation: Institut für Genetik, Technische Universität Braunschweig, Spielmannstraße 7, 38106 Braunschweig, Germany.
authors.forename: M Gabriela
authors.initials: MG
authors.lastname: Roca
authors.forename: Martin
authors.initials: M
authors.lastname: Weichert
authors.forename: Ulrike
authors.initials: U
authors.lastname: Siegmund
authors.forename: Paul
authors.initials: P
authors.lastname: Tudzynski
authors.forename: André
authors.initials: A
authors.lastname: Fleissner
mesh_terms: D020171:Botrytis / Q000166:cytology / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development*; D055786:Gene Knockout Techniques; D025301:Hyphae / Q000166:cytology / Q000201:enzymology / Q000254:growth & development; D008853:Microscopy; D019255:NADPH Oxidases / Q000235:genetics / Q000378:metabolism*; D013172:Spores, Fungal / Q000166:cytology / Q000201:enzymology* / Q000254:growth & development*
chemical_list: D019255:NADPH Oxidases