title: The Arabidopsis peptide kiss of death is an inducer of programmed cell death.
abstract: Programmed cell death (PCD) has a key role in defence and development of all multicellular organisms. In plants, there is a large gap in our knowledge of the molecular machinery involved at the various stages of PCD, especially the early steps. Here, we identify kiss of death (KOD) encoding a 25-amino-acid peptide that activates a PCD pathway in Arabidopsis thaliana. Two mutant alleles of KOD exhibited a reduced PCD of the suspensor, a single file of cells that support embryo development, and a reduced PCD of root hairs after a 55°C heat shock. KOD expression was found to be inducible by biotic and abiotic stresses. Furthermore, KOD expression was sufficient to cause death in leaves or seedlings and to activate caspase-like activities. In addition, KOD-induced PCD required light in leaves and was repressed by the PCD-suppressor genes AtBax inhibitor 1 and p35. KOD expression resulted in depolarization of the mitochondrial membrane, placing KOD above mitochondria dysfunction, an early step in plant PCD. A KOD∷GFP fusion, however, localized in the cytosol of cells and not mitochondria.
authors.affiliation: Laboratoire Génome et Développement des Plantes, CNRS-UMR 5096, Université de Perpignan, Perpignan, France.
authors.forename: Robert
authors.initials: R
authors.lastname: Blanvillain
authors.forename: Bennett
authors.initials: B
authors.lastname: Young
authors.forename: Yao-min
authors.initials: YM
authors.lastname: Cai
authors.forename: Valérie
authors.initials: V
authors.lastname: Hecht
authors.forename: Fabrice
authors.initials: F
authors.lastname: Varoquaux
authors.forename: Valérie
authors.initials: V
authors.lastname: Delorme
authors.forename: Jean-Marc
authors.initials: JM
authors.lastname: Lancelin
authors.forename: Michel
authors.initials: M
authors.lastname: Delseny
authors.forename: Patrick
authors.initials: P
authors.lastname: Gallois
mesh_terms: D017209:Apoptosis; D017360:Arabidopsis / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D006358:Hot Temperature; D053078:Membrane Potential, Mitochondrial; D051336:Mitochondrial Membranes / Q000502:physiology; D050505:Mutant Proteins / Q000235:genetics / Q000378:metabolism; D010455:Peptides / Q000235:genetics / Q000378:metabolism*; D018515:Plant Leaves / Q000378:metabolism; D036226:Seedlings / Q000378:metabolism
chemical_list: D029681:Arabidopsis Proteins; D050505:Mutant Proteins; D010455:Peptides