title: Permeabilization of fungal hyphae by the plant defensin NaD1 occurs through a cell wall-dependent process.
abstract: The antifungal activity of the plant defensin NaD1 involves specific interaction with the fungal cell wall, followed by permeabilization of the plasma membrane and entry of NaD1 into the cytoplasm. Prior to this study, the role of membrane permeabilization in the activity of NaD1, as well as the relevance of cell wall binding, had not been investigated. To address this, the permeabilization of Fusarium oxysporum f. sp. vasinfectum hyphae by NaD1 was investigated and compared with that by other antimicrobial peptides, including the cecropin-melittin hybrid peptide CP-29, the bovine peptide BMAP-28, and the human peptide LL-37, which are believed to act largely through membrane disruption. NaD1 appeared to permeabilize cells via a novel mechanism that required the presence of the fungal cell wall. NaD1 and Bac2A, a linear variant of the bovine peptide bactenecin, were able to enter the cytoplasm of treated hyphae, indicating that cell death is accelerated by interaction with intracellular targets.
authors.affiliation: Department of Biochemistry, La Trobe University, Melbourne, Victoria 3086, Australia.
authors.forename: Nicole L
authors.initials: NL
authors.lastname: van der Weerden
authors.forename: Robert E W
authors.initials: RE
authors.lastname: Hancock
authors.forename: Marilyn A
authors.initials: MA
authors.lastname: Anderson
mesh_terms: D000935:Antifungal Agents / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology; D002463:Cell Membrane Permeability / Q000187:drug effects; D002473:Cell Wall / Q000737:chemistry / Q000187:drug effects / Q000378:metabolism*; D023082:Defensins / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology; D005670:Fusarium / Q000737:chemistry / Q000187:drug effects / Q000378:metabolism*; D054884:Host-Pathogen Interactions; D025301:Hyphae / Q000737:chemistry / Q000187:drug effects / Q000378:metabolism*; D007700:Kinetics; D050296:Microbial Viability / Q000187:drug effects; D010935:Plant Diseases / Q000382:microbiology*; D010940:Plant Proteins / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology; D014026:Nicotiana / Q000737:chemistry / Q000378:metabolism
chemical_list: D000935:Antifungal Agents; D023082:Defensins; D010940:Plant Proteins