title: Production of an engineered killer peptide in Nicotiana benthamiana by using a potato virus X expression system.
abstract: The decapeptide killer peptide (KP) derived from the sequence of a single-chain, anti-idiotypic antibody acting as a functional internal image of a microbicidal, broad-spectrum yeast killer toxin (KT) was shown to exert a strong microbicidal activity against human pathogens. With the aim to exploit this peptide to confer resistance to plant pathogens, we assayed its antimicrobial activity against a broad spectrum of phytopathogenic bacteria and fungi. Synthetic KP exhibited antimicrobial activity in vitro towards Pseudomonas syringae, Erwinia carotovora, Botrytis cinerea, and Fusarium oxysporum. KP was also expressed in plants by using a Potato virus X (PVX)-derived vector as a fusion to the viral coat protein, yielding chimeric virus particles (CVPs) displaying the heterologous peptide. Purified CVPs showed enhanced antimicrobial activity against the above-mentioned plant pathogens and human pathogens such as Staphylococcus aureus and Candida albicans. Moreover, in vivo assays designed to challenge KP-expressing plants (as CVPs) with Pseudomonas syringae pv. tabaci showed enhanced resistance to bacterial attack. The results indicate that the PVX-based display system is a high-yield, rapid, and efficient method to produce and evaluate antimicrobial peptides in plants, representing a milestone for the large-scale production of high-added-value peptides through molecular farming. Moreover, KP is a promising molecule to be stably engineered in plants to confer broad-spectrum resistance to phytopathogens.
authors.affiliation: ENEA, UTS Biotecnologie, Sezione Genetica e Genomica Vegetale, C.R. Casaccia, P.O. Box 2400, I-00100 Rome, Italy.
authors.forename: Marcello
authors.initials: M
authors.lastname: Donini
authors.forename: Chiara
authors.initials: C
authors.lastname: Lico
authors.forename: Selene
authors.initials: S
authors.lastname: Baschieri
authors.forename: Stefania
authors.initials: S
authors.lastname: Conti
authors.forename: Walter
authors.initials: W
authors.lastname: Magliani
authors.forename: Luciano
authors.initials: L
authors.lastname: Polonelli
authors.forename: Eugenio
authors.initials: E
authors.lastname: Benvenuto
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D000935:Antifungal Agents / Q000494:pharmacology; D001709:Biotechnology / Q000379:methods; D036022:Capsid Proteins / Q000235:genetics / Q000378:metabolism; D055646:Killer Factors, Yeast; D008826:Microbial Sensitivity Tests; D010455:Peptides / Q000138:chemical synthesis / Q000235:genetics / Q000378:metabolism* / Q000494:pharmacology; D010935:Plant Diseases / Q000382:microbiology; D018515:Plant Leaves / Q000382:microbiology; D030821:Plants, Genetically Modified; D017863:Potexvirus / Q000235:genetics* / Q000378:metabolism; D015202:Protein Engineering / Q000379:methods; D011506:Proteins / Q000138:chemical synthesis / Q000235:genetics / Q000378:metabolism* / Q000494:pharmacology; D044224:Pseudomonas syringae / Q000187:drug effects / Q000472:pathogenicity; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D014026:Nicotiana / Q000235:genetics* / Q000378:metabolism / Q000382:microbiology; D014771:Virion / Q000378:metabolism
chemical_list: D000900:Anti-Bacterial Agents; D000935:Antifungal Agents; D036022:Capsid Proteins; D055646:Killer Factors, Yeast; D010455:Peptides; D011506:Proteins; D011993:Recombinant Fusion Proteins