title: Grape marc extract causes early perception events, defence reactions and hypersensitive response in cultured tobacco cells.
abstract: Grape marc extract (GME) showed elicitor activity on suspension-cultured cells of tobacco. The BY-2 cells reacted to GME (0.25% and 0.125%) with a long-sustained pH rise in their growth medium. Using EGTA or LaCl3, we showed that extracellular alkalinization depended on Ca(2+) mobilization. The tobacco BY-2 cells challenged with GME promoted cell death and the upregulation of defence-related genes such as PR3, PAL and CCoAOMT. Cell death rate was quantified using an experimental calibrated Evans Blue assay. The GME-induced cell death was dose-dependent and occurred in 24 h. Longer exposure increased the extent of tobacco cell death. To investigate a potential hypersensitive reaction, we tested the effect of various inhibitors of protein synthesis (cycloheximide) and proteases (aprotinin, pepstatin and E-64) on GME-induced cell death. All these chemicals reduced GME-induced cell death rate in 30 min. Overall, our findings indicate that GME elicits early perception events, defence reactions and cell death requiring protein synthesis and proteases.
authors.affiliation: Clermont Université, Université Blaise Pascal, UMR INRA 547 PIAF, 24 avenue des Landais, BP 10448, 63000 Clermont-Ferrand, France.
authors.forename: R
authors.initials: R
authors.lastname: Benouaret
authors.affiliation: Clermont Université, Université Blaise Pascal, UMR INRA 547 PIAF, 24 avenue des Landais, BP 10448, 63000 Clermont-Ferrand, France.
authors.forename: E
authors.initials: E
authors.lastname: Goujon
authors.affiliation: Clermont Université, Université Blaise Pascal, UMR INRA 547 PIAF, 24 avenue des Landais, BP 10448, 63000 Clermont-Ferrand, France. Electronic address: Pascale.GOUPIL@univ-bpclermont.fr.
authors.forename: P
authors.initials: P
authors.lastname: Goupil
mesh_terms: D007611:Aprotinin / Q000494:pharmacology; D016923:Cell Death; D002478:Cells, Cultured; D003513:Cycloheximide / Q000494:pharmacology; D060467:Disease Resistance / Q000235:genetics; D017343:Genes, Plant; D006863:Hydrogen-Ion Concentration; D007930:Leucine / Q000031:analogs & derivatives / Q000494:pharmacology; D010436:Pepstatins / Q000494:pharmacology; D010447:Peptide Hydrolases / Q000378:metabolism; D010935:Plant Diseases; D010936:Plant Extracts / Q000494:pharmacology*; D010940:Plant Proteins / Q000378:metabolism; D014026:Nicotiana / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism; D015854:Up-Regulation; D027843:Vitis
chemical_list: D010436:Pepstatins; D010936:Plant Extracts; D010940:Plant Proteins; D007611:Aprotinin; D003513:Cycloheximide; D010447:Peptide Hydrolases; D007930:Leucine; C024974:E 64; C031375:pepstatin
keywords: Cell death; Grape marc; Hypersensitive reaction; Plant defence; Protease inhibitors; Tobacco BY-2