title: The myosin motor domain-containing chitin synthase PdChsVII is required for development, cell wall integrity and virulence in the citrus postharvest pathogen Penicillium digitatum.
abstract: Chitin is an essential component of the fungal cell wall and a potential target in the development of new antifungal compounds, due to its presence in fungi and not in plants or vertebrates. Chitin synthase genes (chs) constitute a complex family in filamentous fungi and are involved in fungal development, morphogenesis, pathogenesis and virulence. In this study, additional chs genes in the citrus postharvest pathogen Penicillium digitatum have been identified. Comparative analyses included each PdChs in each one of the classes I to VII previously established, and support the grouping of these into three divisions. Disruption of the gene coding PdChsVII, which contains a short version of a myosin motor domain, has been achieved by using Agrobacterium tumefaciens-mediated transformation and revealed its role in the life cycle of the fungus. Disruption strains were viable but showed reduced growth and conidia production. Moreover, Pdchs mutants developed morphological defects as balloon-like enlarged cells and increased chitin content, indicative of an altered cell wall structure. Gene disruption also increased susceptibility to antifungal compounds such as calcofluor white (CFW), sodium dodecyl sulfate (SDS), hydroxide peroxide (H2O2) and commercial fungicides, but significantly no change was observed in the sensitivity to antifungal peptides. The PdchsVII mutants were able to infect citrus fruit and produced tissue maceration, although had reduced virulence and most importantly were greatly impaired in the production of visible mycelium and conidia on the fruit.
authors.affiliation: Food Science Department, Instituto de Agroquímica y Tecnología de Alimentos (IATA), Consejo Superior de Investigaciones Científicas (CSIC), Avda Agustín Escardino 7, 46980 Paterna, Valencia, Spain. Electronic address: mgandia@iata.csic.es.
authors.forename: Mónica
authors.initials: M
authors.lastname: Gandía
authors.affiliation: Food Science Department, Instituto de Agroquímica y Tecnología de Alimentos (IATA), Consejo Superior de Investigaciones Científicas (CSIC), Avda Agustín Escardino 7, 46980 Paterna, Valencia, Spain.
authors.forename: Eleonora
authors.initials: E
authors.lastname: Harries
authors.affiliation: Food Science Department, Instituto de Agroquímica y Tecnología de Alimentos (IATA), Consejo Superior de Investigaciones Científicas (CSIC), Avda Agustín Escardino 7, 46980 Paterna, Valencia, Spain.
authors.forename: Jose F
authors.initials: JF
authors.lastname: Marcos
mesh_terms: D000935:Antifungal Agents / Q000494:pharmacology; D001557:Benzenesulfonates / Q000494:pharmacology; D002473:Cell Wall / Q000378:metabolism; D002687:Chitin Synthase / Q000235:genetics / Q000378:metabolism*; D002957:Citrus / Q000382:microbiology*; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism*; D005659:Fungicides, Industrial / Q000494:pharmacology; D006861:Hydrogen Peroxide / Q000494:pharmacology; D009154:Mutation; D009218:Myosins / Q000235:genetics*; D010407:Penicillium / Q000187:drug effects / Q000472:pathogenicity / Q000502:physiology*; D010802:Phylogeny; D010935:Plant Diseases / Q000382:microbiology; D017434:Protein Structure, Tertiary; D012967:Sodium Dodecyl Sulfate / Q000494:pharmacology; D014774:Virulence
chemical_list: D000935:Antifungal Agents; D001557:Benzenesulfonates; D005656:Fungal Proteins; D005659:Fungicides, Industrial; D012967:Sodium Dodecyl Sulfate; C007061:C.I. Fluorescent Brightening Agent 28; D006861:Hydrogen Peroxide; D002687:Chitin Synthase; D009218:Myosins
keywords: Cell wall; Chitin synthase; Citrus; Penicillium digitatum; Postharvest pathology