title: Involvement of the Fusarium graminearum cerato-platanin proteins in fungal growth and plant infection.
abstract: The genome of Fusarium graminearum, a necrotrophic fungal pathogen causing Fusarium head blight (FHB) disease of wheat, barley and other cereal grains, contains five genes putatively encoding for proteins with a cerato-platanin domain. Cerato-platanins are small secreted cysteine-rich proteins possibly localized in the fungal cell walls and also contributing to the virulence. Two of these F. graminearum proteins (FgCPP1 and FgCPP2) belong to the class of SnodProt proteins which exhibit phytotoxic activity in the fungal pathogens Botrytis cinerea and Magnaporthe grisea. In order to verify their contribution during plant infection and fungal growth, single and double gene knock-out mutants were produced and no reduction in symptoms severity was observed compared to the wild type strain on both soybean and wheat spikes. Histological analysis performed by fluorescence microscopy on wheat spikelets infected with mutants constitutively expressing the dsRed confirmed that FgCPPs do not contribute to fungal virulence. In particular, the formation of compound appressoria on wheat paleas was unchanged. Looking for other functions of these proteins, the double mutant was characterized by in vitro experiments. The mutant was inhibited by salt and H2O2stress similarly to wild type. Though no growth difference was observed on glucose, the mutant grew better than wild type on carboxymethyl cellulose. Additionally, the mutant's mycelium was more affected by treatments with chitinase and β-1,3-glucanase, thus indicating that FgCPPs could protect fungal cell wall polysaccharides from enzymatic degradation.
authors.affiliation: Dipartimento del Territorio e Sistemi Agro-Forestali (TESAF), Research Group in Plant Pathology, Università degli Studi di Padova, Viale dell'Università 16, 35020, Legnaro, Italy.
authors.forename: Alessandra
authors.initials: A
authors.lastname: Quarantin
authors.affiliation: Biocenter Klein Flottbek, Molecular Phytopathology and Genetics, University of Hamburg, Hamburg, Germany.
authors.forename: Anika
authors.initials: A
authors.lastname: Glasenapp
authors.affiliation: Biocenter Klein Flottbek, Molecular Phytopathology and Genetics, University of Hamburg, Hamburg, Germany.
authors.forename: Wilhelm
authors.initials: W
authors.lastname: Schäfer
authors.affiliation: Dipartimento del Territorio e Sistemi Agro-Forestali (TESAF), Research Group in Plant Pathology, Università degli Studi di Padova, Viale dell'Università 16, 35020, Legnaro, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Favaron
authors.affiliation: Dipartimento del Territorio e Sistemi Agro-Forestali (TESAF), Research Group in Plant Pathology, Università degli Studi di Padova, Viale dell'Università 16, 35020, Legnaro, Italy. Electronic address: luca.sella@unipd.it.
authors.forename: Luca
authors.initials: L
authors.lastname: Sella
mesh_terms: D003198:Computer Simulation; D002523:Edible Grain / Q000382:microbiology; D005656:Fungal Proteins / Q000145:classification / Q000235:genetics / Q000502:physiology*; D005670:Fusarium / Q000235:genetics / Q000472:pathogenicity* / Q000502:physiology; D015870:Gene Expression; D055786:Gene Knockout Techniques; D005800:Genes, Fungal; D010802:Phylogeny; D010935:Plant Diseases / Q000382:microbiology*; D013025:Glycine max / Q000382:microbiology; D014908:Triticum / Q000382:microbiology; D014774:Virulence / Q000235:genetics / Q000502:physiology
chemical_list: D005656:Fungal Proteins
keywords: Cerato-platanin; Fungal cell wall polysaccharides; Fusarium graminearum; Gene disruption; SnodProt; Virulence