title: Are grapevine stomata involved in the elicitor-induced protection against downy mildew?
abstract: Stomata, natural pores bordered by guard cells, regulate transpiration and gas exchanges between plant leaves and the atmosphere. These natural openings also constitute a way of penetration for microorganisms. In plants, the perception of potentially pathogenic microorganisms or elicitors of defense reactions induces a cascade of events, including H(2)O(2) production, that allows the activation of defense genes, leading to defense reactions. Similar signaling events occur in guard cells in response to the perception of abscisic acid (ABA), leading to stomatal closure. Moreover, few elicitors were reported to induce stomatal closure in Arabidopsis and Vicia faba leaves. Because responses to ABA and elicitors share common signaling events, it led us to question whether stomatal movements and H(2)O(2) production in guard cells could play a key role in elicitor-induced protection against pathogens that use stomata for infection. This study was performed using the grapevine-Plasmopara viticola pathosystem. Using epidermal peels, we showed that, as for ABA, the elicitor-induced stomatal closure is mediated by reactive oxygen species (ROS) production in guard cells. In plants, we observed that the protection against downy mildew induced by some elicitors is probably not due only to effects on stomatal movements or to a guard-cell-specific activation of ROS production.
authors: Unité Mixte de Recherche INRA 1088/CNRS 5184/ Université de Bourgogne Plante-Microbe-Environnement, 17 rue Sully, BP 86510, 21065 Dijon cedex, France.
authors: Mathilde
authors: M
authors: Allègre
authors: Marie-Claire
authors: MC
authors: Héloir
authors: Sophie
authors: S
authors: Trouvelot
authors: Xavier
authors: X
authors: Daire
authors: Alain
authors: A
authors: Pugin
authors: D
authors: D
authors: Wendehenne
authors: Marielle
authors: M
authors: Adrian
mesh_terms: D000040:Abscisic Acid / Q000494:pharmacology; D006861:Hydrogen Peroxide / Q000378:metabolism; D007113:Immunity, Innate; D008027:Light; D009868:Oomycetes / Q000502:physiology*; D018515:Plant Leaves / Q000378:metabolism / Q000382:microbiology; D054046:Plant Stomata / Q000382:microbiology / Q000502:physiology* / Q000528:radiation effects; D017382:Reactive Oxygen Species / Q000378:metabolism; D027843:Vitis / Q000382:microbiology* / Q000528:radiation effects
chemical_list: D017382:Reactive Oxygen Species; D000040:Abscisic Acid; D006861:Hydrogen Peroxide