title: Role of the modification in root exudation induced by arbuscular mycorrhizal colonization on the intraradical growth of Phytophthora nicotianae in tomato.
abstract: We studied the role of modification in root exudation induced by colonization with Glomus intraradices and Glomus mosseae in the growth of Phytophthora nicotianae in tomato roots. Plants were grown in a compartmentalized plant growth system and were either inoculated with the AM fungi or received exudates from mycorrhizal plants, with the corresponding controls. Three weeks after planting, the plants were inoculated or not with P. nicotianae growing from an adjacent compartment. At harvest, P. nicotianae biomass was significantly reduced in roots colonized with G. intraradices or G. mosseae in comparison to non-colonized roots. Conversely, pathogen biomass was similar in non-colonized roots supplied with exudates collected from mycorrhizal or non-mycorrhizal roots, or with water. We cannot rule out that a mycorrhiza-mediated modification in root exudation may take place, but our results did not support that a change in pathogen chemotactic responses to host root exudates may be involved in the inhibition of P. nicotianae.
authors.affiliation: Institut de recherche en biologie végétale, Université de Montréal & Jardin botanique de Montréal, 4101 East Sherbrooke Street, Montreal, QC, H1X 2B2, Canada.
authors.forename: L
authors.initials: L
authors.lastname: Lioussanne
authors.affiliation: Bio-P2 Research Unit, Department of Chemical Engineering, École Polytechnique de Montréal, P.O. Box 6079, Centre-ville Station, Montreal, QC, H3C 3A7, Canada.
authors.forename: M
authors.initials: M
authors.lastname: Jolicoeur
authors.affiliation: Institut de recherche en biologie végétale, Université de Montréal & Jardin botanique de Montréal, 4101 East Sherbrooke Street, Montreal, QC, H1X 2B2, Canada. marc.st-arnaud@umontreal.ca.
authors.forename: M
authors.initials: M
authors.lastname: St-Arnaud
mesh_terms: D000898:Antibiosis; D055137:Glomeromycota / Q000254:growth & development*; D018551:Solanum lycopersicum / Q000382:microbiology* / Q000502:physiology; D038821:Mycorrhizae / Q000254:growth & development*; D010838:Phytophthora / Q000254:growth & development*; D018517:Plant Roots / Q000382:microbiology* / Q000502:physiology