title: Calcium signatures and signaling in cytosol and organelles of tobacco cells induced by plant defense elicitors.
abstract: Calcium signatures induced by two elicitors of plant defense reactions, namely cryptogein and oligogalacturonides, were monitored at the subcellular level, using apoaequorin-transformed Nicotiana tabacum var Xanthi cells, in which the apoaequorin calcium sensor was targeted either to cytosol, mitochondria or chloroplasts. Our study showed that both elicitors induced specific Ca(2+) signatures in each compartment, with the most striking difference relying on duration. Common properties also emerged from the analysis of Ca(2+) signatures: both elicitors induced a biphasic cytosolic [Ca(2+)] elevation together with a single mitochondrial [Ca(2+)] elevation concomitant with the first cytosolic [Ca(2+)] peak. In addition, both elicitors induced a chloroplastic [Ca(2+)] elevation peaking later in comparison to cytosolic [Ca(2+)] elevation. In cryptogein-treated cells, pharmacological studies indicated that IP(3) should play an important role in Ca(2+) signaling contrarily to cADPR or nitric oxide, which have limited or no effect on [Ca(2+)] variations. Our data also showed that, depending on [Ca(2+)] fluxes at the plasma membrane, cryptogein triggered a mitochondrial respiration increase and affected excess energy dissipation mechanisms in chloroplasts. Altogether the results indicate that cryptogein profoundly impacted cell functions at many levels, including organelles.
authors.affiliation: INRA, UMR Pôle Mécanisme et Gestion des Interactions Plantes-microorganismes - ERL CNRS, Dijon, France.
authors.forename: Hamid
authors.initials: H
authors.lastname: Manzoor
authors.forename: Annick
authors.initials: A
authors.lastname: Chiltz
authors.forename: Siham
authors.initials: S
authors.lastname: Madani
authors.forename: Parul
authors.initials: P
authors.lastname: Vatsa
authors.forename: Benoît
authors.initials: B
authors.lastname: Schoefs
authors.forename: Alain
authors.initials: A
authors.lastname: Pugin
authors.forename: Angela
authors.initials: A
authors.lastname: Garcia-Brugger
mesh_terms: D017920:Antiporters / Q000737:chemistry; D002118:Calcium / Q000737:chemistry*; D020013:Calcium Signaling / Q000187:drug effects*; D027682:Cation Transport Proteins / Q000737:chemistry; D002462:Cell Membrane / Q000737:chemistry; D002734:Chlorophyll / Q000737:chemistry; D002736:Chloroplasts / Q000737:chemistry / Q000187:drug effects; D003600:Cytosol / Q000737:chemistry*; D005453:Fluorescence; D005656:Fungal Proteins / Q000494:pharmacology; D008928:Mitochondria / Q000737:chemistry / Q000187:drug effects; D010100:Oxygen / Q000737:chemistry; D010838:Phytophthora / Q000737:chemistry; D059828:Plant Cells / Q000737:chemistry / Q000187:drug effects*; D013997:Time Factors; D014026:Nicotiana / Q000737:chemistry* / Q000166:cytology / Q000187:drug effects
chemical_list: D017920:Antiporters; D027682:Cation Transport Proteins; D005656:Fungal Proteins; C027614:calcium-hydrogen antiporters; C061032:cryptogein protein, Phytophthora cryptogea; D002734:Chlorophyll; D010100:Oxygen; D002118:Calcium