title: Antimicrobial activity of potato aspartic proteases (StAPs) involves membrane permeabilization.
abstract: Solanum tuberosum aspartic proteases (StAPs) with antimicrobial activity are induced after abiotic and biotic stress. In this study the ability of StAPs to produce a direct antimicrobial effect was investigated. Viability assays demonstrated that StAPs are able to kill spores of Fusarium solani and Phytophthora infestans in a dose-dependent manner. Localization experiments with FITC-labelled StAPs proved that the proteins interact directly with the surface of spores and hyphae of F. solani and P. infestans. Moreover, incubation of spores and hyphae with StAPs resulted in membrane permeabilization, as shown by the uptake of the fluorescent dye SYTOX Green. It is concluded that the antimicrobial effect of StAPs against F. solani and P. infestans is caused by a direct interaction with the microbial surfaces followed by membrane permeabilization.
authors.affiliation: Instituto de Investigaciones Biológicas, Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Mar del Plata, CC 1247, Argentina.
authors.forename: Julieta R
authors.initials: JR
authors.lastname: Mendieta
authors.affiliation: Instituto de Investigaciones Biológicas, Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Mar del Plata, CC 1247, Argentina.
authors.forename: Mariana R
authors.initials: MR
authors.lastname: Pagano
authors.affiliation: Instituto de Investigaciones Biológicas, Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Mar del Plata, CC 1247, Argentina.
authors.forename: Fernando F
authors.initials: FF
authors.lastname: Muñoz
authors.affiliation: Instituto de Investigaciones Biológicas, Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Mar del Plata, CC 1247, Argentina.
authors.forename: Gustavo R
authors.initials: GR
authors.lastname: Daleo
authors.affiliation: Instituto de Investigaciones Biológicas, Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Mar del Plata, CC 1247, Argentina.
authors.forename: María G
authors.initials: MG
authors.lastname: Guevara
mesh_terms: D000935:Antifungal Agents / Q000494:pharmacology*; D016282:Aspartic Acid Endopeptidases / Q000494:pharmacology*; D002463:Cell Membrane Permeability; D004305:Dose-Response Relationship, Drug; D005670:Fusarium / Q000187:drug effects; D009994:Osmolar Concentration; D010838:Phytophthora / Q000187:drug effects; D010940:Plant Proteins / Q000494:pharmacology*; D017382:Reactive Oxygen Species; D011198:Solanum tuberosum / Q000201:enzymology*
chemical_list: D000935:Antifungal Agents; D010940:Plant Proteins; D017382:Reactive Oxygen Species; D016282:Aspartic Acid Endopeptidases