title: Plant defensin AhPDF1.1 is not secreted in leaves but it accumulates in intracellular compartments.
abstract: • Apart from their antifungal role, plant defensins have recently been shown to be involved in abiotic stress tolerance or in inhibition of root growth when added in plant culture medium. We studied the subcellular localization of these proteins, which may account for these different roles. • Stable and transient expression of AhPDF1.1::GFP (green fluorescent protein) fusion proteins were analysed in yeast and plants. Functional tests established that the GFP tag did not alter the action of the defensin. Subcellular localization of AhPDF1.1 was characterized: by imaging AhPDF1.1::GFP together with organelle markers; and by immunolabelling AhPDF1.1 in Arabidopsis halleri and Arabidopsis thaliana leaves using a polyclonal serum. • All our independent approaches demonstrated that AhPDF1.1 is retained in intracellular compartments on the way to the lytic vacuole, instead of being addressed to the apoplasm. • These findings challenge the commonly accepted idea of secretion of defensins. The subcellular localization highlighted in this study could partly explain the dual role of plant defensins on plant cells and is of major importance to unravel the mechanisms of action of these proteins at the cellular level.
authors.affiliation: Laboratoire de Biochimie & Physiologie Moléculaire des Plantes, UMR Université Montpellier 2, CNRS, INRA, Montpellier SupAgro, 2 place Viala, F-34060 Montpellier Cedex 02, France.
authors.forename: Ronald J F J
authors.initials: RJFJ
authors.lastname: Oomen
authors.affiliation: Laboratoire de Biochimie & Physiologie Moléculaire des Plantes, UMR Université Montpellier 2, CNRS, INRA, Montpellier SupAgro, 2 place Viala, F-34060 Montpellier Cedex 02, France.
authors.forename: Emilie
authors.initials: E
authors.lastname: Séveno-Carpentier
authors.affiliation: Laboratoire de Biochimie & Physiologie Moléculaire des Plantes, UMR Université Montpellier 2, CNRS, INRA, Montpellier SupAgro, 2 place Viala, F-34060 Montpellier Cedex 02, France.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Ricodeau
authors.affiliation: Laboratoire de Biochimie & Physiologie Moléculaire des Plantes, UMR Université Montpellier 2, CNRS, INRA, Montpellier SupAgro, 2 place Viala, F-34060 Montpellier Cedex 02, France.
authors.forename: Caroline
authors.initials: C
authors.lastname: Bournaud
authors.affiliation: Laboratoire de Biochimie & Physiologie Moléculaire des Plantes, UMR Université Montpellier 2, CNRS, INRA, Montpellier SupAgro, 2 place Viala, F-34060 Montpellier Cedex 02, France.
authors.forename: Geneviève
authors.initials: G
authors.lastname: Conéjéro
authors.affiliation: Laboratoire de Biochimie & Physiologie Moléculaire des Plantes, UMR Université Montpellier 2, CNRS, INRA, Montpellier SupAgro, 2 place Viala, F-34060 Montpellier Cedex 02, France.
authors.forename: Nadine
authors.initials: N
authors.lastname: Paris
authors.affiliation: Laboratoire de Biochimie & Physiologie Moléculaire des Plantes, UMR Université Montpellier 2, CNRS, INRA, Montpellier SupAgro, 2 place Viala, F-34060 Montpellier Cedex 02, France.
authors.forename: Pierre
authors.initials: P
authors.lastname: Berthomieu
authors.affiliation: Laboratoire de Biochimie & Physiologie Moléculaire des Plantes, UMR Université Montpellier 2, CNRS, INRA, Montpellier SupAgro, 2 place Viala, F-34060 Montpellier Cedex 02, France.
authors.forename: Laurence
authors.initials: L
authors.lastname: Marquès
mesh_terms: D000222:Adaptation, Physiological / Q000187:drug effects; D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000187:drug effects / Q000378:metabolism* / Q000502:physiology; D029681:Arabidopsis Proteins / Q000737:chemistry / Q000378:metabolism*; D002451:Cell Compartmentation; D002473:Cell Wall / Q000187:drug effects / Q000378:metabolism; D048271:Chitosan / Q000494:pharmacology; D023082:Defensins / Q000737:chemistry / Q000378:metabolism*; D049452:Green Fluorescent Proteins / Q000378:metabolism; D007118:Immunoassay; D042541:Intracellular Space / Q000187:drug effects / Q000378:metabolism*; D008969:Molecular Sequence Data; D018515:Plant Leaves / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D021382:Protein Sorting Signals; D021381:Protein Transport / Q000187:drug effects; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000187:drug effects / Q000378:metabolism; D013329:Structure-Activity Relationship; D013347:Subcellular Fractions / Q000187:drug effects / Q000378:metabolism; D014026:Nicotiana / Q000187:drug effects / Q000378:metabolism; D014617:Vacuoles / Q000187:drug effects / Q000378:metabolism; D015032:Zinc / Q000633:toxicity; D021601:trans-Golgi Network / Q000187:drug effects / Q000378:metabolism
chemical_list: D029681:Arabidopsis Proteins; D023082:Defensins; D021382:Protein Sorting Signals; D011993:Recombinant Fusion Proteins; D049452:Green Fluorescent Proteins; D048271:Chitosan; D015032:Zinc