Grape marc extract causes early perception events, defence reactions and hypersensitive response in cultured tobacco cells

Razik Benouaret (1) , Eric Goujon (1) , Pascale Goupil (1)

1 PIAF - Laboratoire de Physique et Physiologie Intégratives de l'Arbre Fruitier et Forestier

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 Ca2+ 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.

Mots clés: Cell death; Grape marc; Hypersensitive reaction; Plant defence; Protease inhibitors; Tobacco BY-2

Domaines: Biologie végétale; Sciences de l'environnement

Razik Benouaret, Eric Goujon, Pascale Goupil. Grape marc extract causes early perception events, defence reactions and hypersensitive response in cultured tobacco cells. Plant Physiology and Biochemistry, 2014, 77, pp.84-89. ⟨10.1016/j.plaphy.2014.01.021⟩. ⟨hal-00981190⟩