Proteinaceous and oligosaccharidic elicitors induce different calcium signatures in the nucleus of tobacco cells.
We previously reported elevated cytosolic calcium levels in tobacco cells in response to elicitors [D. Lecourieux, C. Mazars, N. Pauly, R. Ranjeva, A. Pugin, Analysis and effects of cytosolic free calcium elevations in response to elicitors in Nicotiana plumbaginifolia cells, Plant Cell 14 (2002) 2627-2641]. These data suggested that in response to elicitors, Ca2+, as a second messenger, was involved in both systemic acquired resistance (RSA) and/or hypersensitive response (HR) depending on calcium signature. Here, we used transformed tobacco cells with apoaequorin expressed in the nucleus to monitor changes in free nuclear calcium concentrations ([Ca2+](nuc)) in response to elicitors. Two types of elicitors are compared: proteins leading to necrosis including four elicitins and harpin, and non-necrotic elicitors including flagellin (flg22) and two oligosaccharidic elicitors, namely the oligogalacturonides (OGs) and the beta-1,3-glucan laminarin. Our data indicate that the proteinaceous elicitors induced a pronounced and sustainable [Ca2+](nuc) elevation, relative to the small effects of oligosaccharidic elicitors. This [Ca2+](nuc) elevation, which seems insufficient to induce cell death, is unlikely to result directly from the diffusion of calcium from the cytosol. The [Ca2+](nuc) rise depends on free cytosolic calcium, IP3, and active oxygen species (AOS) but is independent of nitric oxide.
Lecourieux
David
D
UMR INRA 1088/CNRS 5184/Université de Bourgogne, Plante-Microbe-Environnement, 17 rue de Sully, BP 86510, 21065 Dijon cedex, France.
Lamotte
Olivier
O
Bourque
Stéphane
S
Wendehenne
David
D
Mazars
Christian
C
Ranjeva
Raoul
R
Pugin
Alain
A
D020013:Calcium Signaling / Q000235:genetics / Q000502:physiology*; D002467:Cell Nucleus / Q000235:genetics / Q000378:metabolism*; D002478:Cells, Cultured; D018390:Gene Targeting; D050506:Mutant Chimeric Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D009844:Oligosaccharides / Q000378:metabolism / Q000502:physiology*; D010766:Phosphorylation; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D014026:Nicotiana / Q000166:cytology / Q000235:genetics / Q000378:metabolism*
D050506:Mutant Chimeric Proteins; D009844:Oligosaccharides; D010940:Plant Proteins