Antioxidants in Pinus pinaster roots and mycorrhizal fungi during the early steps of symbiosis

Ectomycorrhizal symbiosis between fungi mycelia and the roots of some plants could have important effects in the levels of antioxidants of both partners. In the present work, the effects of co-culture period in the antioxidant properties and antioxidants (phenolics, tocopherols and sugars) production during early steps of in vitro mycorrhization (Pinus pinaster-Pisolithus arhizus and Pinus pinaster-Paxillus involutus) were evaluated. The studied parameters were determined in each culture element (root, mycelium and medium) in order to understand the response of each partner to the symbiotic association. R arhizus proved to be more compatible with P. pinaster than P. involutus, since the antioxidant activity in the latter species increased from 48 to 72 h, while P. arhizus antioxidant properties decreased at the same period (indicative of less oxidative stress). Despite P. involutus proved to be less suitable to be included in forestation programs using mycorrhization processes, it revealed a higher potential for bioactive compounds production in the early steps of symbiosis. A maximal value of phenolics content was obtained after the first 6 h. (C) 2012 Elsevier B.V. All rights reserved.