title: Increased chitin biosynthesis contributes to the resistance of Penicillium polonicum against the antifungal protein PgAFP.
abstract: Antifungal proteins from molds have been proposed as a valuable tool against unwanted molds, but the resistance of some fungi limits their use. Resistance to antimicrobial peptides has been suggested to be due to lack of interaction with the mold or to a successful response. The antifungal protein PgAFP produced by Penicillium chrysogenum inhibits the growth of various ascomycetes, but not Penicillium polonicum. To study the basis for resistance to this antifungal protein, localization of PgAFP and metabolic, structural, and morphological changes were investigated in P. polonicum. PgAFP bound the outer layer of P. polonicum but not regenerated chitin, suggesting an interaction with specific molecules. Comparative two-dimensional gel electrophoresis (2D-PAGE) and comparative quantitative proteomics revealed changes in the relative abundance of several proteins from ribosome, spliceosome, metabolic, and biosynthesis of secondary metabolite pathways. The proteome changes and an altered permeability reveal an active reaction of P. polonicum to PgAFP. The successful response of the resistant mold seems to be based on the higher abundance of protein Rho GTPase Rho1 that would lead to the increased chitin deposition via cell wall integrity (CWI) signaling pathway. Thus, combined treatment with chitinases could provide a complementary means to combat resistance to antifungal proteins.
authors.affiliation: Food Hygiene and Safety, Institute of Meat Products, University of Extremadura, Cáceres, Spain.
authors.forename: Josué
authors.initials: J
authors.lastname: Delgado
authors.affiliation: Department of Biology, Maynooth University, Maynooth, Co., Kildare, Ireland.
authors.forename: Rebecca A
authors.initials: RA
authors.lastname: Owens
authors.affiliation: Department of Biology, Maynooth University, Maynooth, Co., Kildare, Ireland.
authors.forename: Sean
authors.initials: S
authors.lastname: Doyle
authors.affiliation: Food Hygiene and Safety, Institute of Meat Products, University of Extremadura, Cáceres, Spain. masensio@unex.es.
authors.forename: Miguel A
authors.initials: MA
authors.lastname: Asensio
authors.affiliation: Food Hygiene and Safety, Institute of Meat Products, University of Extremadura, Cáceres, Spain.
authors.forename: Félix
authors.initials: F
authors.lastname: Núñez
mesh_terms: D000935:Antifungal Agents / Q000378:metabolism*; D023181:Antimicrobial Cationic Peptides / Q000378:metabolism*; D002473:Cell Wall / Q000378:metabolism; D002686:Chitin / Q000096:biosynthesis*; D025141:Drug Resistance, Fungal; D005658:Fungi; D010407:Penicillium / Q000737:chemistry / Q000187:drug effects* / Q000378:metabolism*; D020543:Proteome / Q000032:analysis; D040901:Proteomics; D015398:Signal Transduction; D020741:rho GTP-Binding Proteins / Q000378:metabolism
chemical_list: D000935:Antifungal Agents; D023181:Antimicrobial Cationic Peptides; D020543:Proteome; D002686:Chitin; D020741:rho GTP-Binding Proteins
keywords: Antifungal proteins; Cell wall integrity pathway; Chitin; Penicillium polonicum; Proteomics; Resistance