Antioxidant potential of fungi and seedlings during mycorrhizal induction
Conference Paper
Overview
Overview
abstract
Mycorrhizal associations implicate a chemical recognizing process being the establishment of the
symbiosis triggered by signals produced by both partners. We evaluated the establishment of mycorrhizal
symbiosis between two ectomycorrhizal (ECM) fungi species, Paxillus involutus and Pisolithus arhizus,
and two different symbionts, Pinus pinaster and Castanea sativa. ln a first step, we monitored the growth
of the two ECM species in the presence and absence of the symbiont P. pinaster. Then we evaluated the
antioxidant properties of fungi and seedlings, in response to the symbiotic process, under different
contact periods. After, we tested the mycorrhization process between the two fungi species and C.
sativa seedlings, assessing the production of tocopherols and sugars produced by both partners during
the earlier steps of symbiosis. The antioxidant properties were assessed through four in vitro assays:
Folin-Ciocalteu assay (total phenolics), Ferricyanide/Prussian blue assay, 2,2-diphenyl-1-picrylhydrazyl
(DPPH) radical scavenging activity and Beta-carotene/linoleate system assay. Tocopherols and sugars were
analysed by HPLC-fluorescence and HPLC-RI, respectively. ECM fungi grew less in the presence of P.
pinaster, with P. arhizus being less affected (in growth) and thus being more adapted to this association.
Regarding the mechanisms of oxidative stress in ectomycorrhizal associations, t he response of the
fungi and plants to the contact with the host is somehow specific, revealing different forms of mutual
recognition. Considering bioactive compounds production, P. involutus revea led a maximal value of
phenolics after 6h in co-culture with P. pinaster and P. arhizus revealed increased contents of sugars and tocopherols when in contact with C. sativa.
