Histolocalisation de substances phénoliques intervenant lors d'interactions plante-pathogène chez le tournesol et la vigne

Abstract

Summary: Some phenolic compounds were studied histochemically before and after infection during two kinds of interactions: Helianthus resinosus/Sclerotinia sclerotiorum and Vitis spp./Plasmopara viticola. H. resinosus is a wild sunflower species chosen for its high tolerance to S. sclerotiorum. For grapevine, three species of different susceptibilities were analysed. Microscopical observations after marking of cross-sections by different coloured or fluorescent probes showed presence of phenolic compounds pre-existent to infection in resistant species (hydroxycinnamic and gallic derivatives). After infection occured accumulation of different phenolic compounds, (caffeic derivatives and flavonoids) more rapidly in resistant species which certainly avoid parasite extension. © 1997, Taylor & Francis Group, LLC.