title: Induction of defence mechanisms in grapevine leaves by emodin- and anthraquinone-rich plant extracts and their conferred resistance to downy mildew.
abstract: The ability of two plant extracts, Rheum palmatum root extract (RPRE) and Frangula alnus bark extract (FABE), to protect Vitis vinifera leaves from Plasmopara viticola infection was evaluated. These natural products are toxic to the pathogen and induce defence reactions in a susceptible cultivar of V. vinifera (V. vinifera cv. Chasselas), including stilbenic phytoalexin accumulation, enhanced peroxidase (EC 1.11.1.7) activity, and a hypersensitive reaction. Inhibition of the first stage of biotrophic hyphal development of P. Viticola by the two plant extracts was observed. HPLC-DAD-MS analysis showed that these two natural extracts contain many phenolic compounds belonging to the anthraquinone family, such as rhein, frangulin A, emodin, aloe-emodin, chrysophanol, and physcion. Emodin alone is able to impair P. viticola development and to stimulate viniferins and the accumulation of pterostilbene.
authors.affiliation: Swiss Federal Research Station Agroscope Changins-Wädenswil, Route de Duillier, P.O. Box 1012, CH-1260 Nyon, Switzerland. sophie.godard@acw.admin.ch
authors.forename: Sophie
authors.initials: S
authors.lastname: Godard
authors.forename: Ivan
authors.initials: I
authors.lastname: Slacanin
authors.forename: Olivier
authors.initials: O
authors.lastname: Viret
authors.forename: Katia
authors.initials: K
authors.lastname: Gindro
mesh_terms: D000880:Anthraquinones / Q000737:chemistry*; D002845:Chromatography / Q000379:methods; D002851:Chromatography, High Pressure Liquid; D004642:Emodin / Q000737:chemistry* / Q000494:pharmacology; D013058:Mass Spectrometry / Q000379:methods; D008954:Models, Biological; D010544:Peroxidases / Q000378:metabolism; D018515:Plant Leaves / Q000378:metabolism*; D018521:Plant Physiological Phenomena; D018517:Plant Roots / Q000378:metabolism*; D017382:Reactive Oxygen Species; D000077185:Resveratrol; D012997:Solvents / Q000737:chemistry; D013267:Stilbenes / Q000737:chemistry / Q000494:pharmacology; D013997:Time Factors
chemical_list: D000880:Anthraquinones; D017382:Reactive Oxygen Species; D012997:Solvents; D013267:Stilbenes; C107773:pterostilbene; D010544:Peroxidases; D004642:Emodin; D000077185:Resveratrol