Interaction of ECM mycorrhiza with Mn2+heavy metal and its effect on the oxidative stress in Pistachio threes

Heavy metals reduce the plant growth and adversely affect plant performance potential. Heavy metals also induce the formation of reactive oxygen species leading to cell damage. Plants deal with heavy metal stress by activating enzymatic and non-enzymatic antioxidant systems.Agaricus bisporus (J. Lange), an edible mushroom has been observed to grow under pistachio trees (Pistacia vera L.) plantations in orchards of Rafsanjan, Kerman and it forms ectomycorrhiza with the tree. In order to evaluation of alleviating effects of ectomycorrhizal colonization on Mn2+ toxicity, a study was performed using pistachio plants and Agaricus bisporus fungus as factorial in a completely randomized design with three replications. The experiment included two factors: mycorrhizal (M) and non-mycorrhizal (NM) pistachio plants and five levels of the Mn2+ concentrations (0, 200, 400, 600 and 800 μm) in 3 replicates. In this study, the experiment was conducted to investigate the effect of ectomycorrhizal colonization in the alleviation of oxidative stress and improvements of the antioxidant enzyme activities accumulation in pistachio trees (Akbari cultivar). The results showed that the increase of Mn2+ concentration caused an induction in antioxidative enzymes activity in the leaves of the M and NM plants, but it was dramatically more in M plants. The results showed that the Mn translocated from root to shoot in M plants was lower than NM plants. The amelioration of Mn toxicity by A.bisporus may be a result of improving the antioxidant defense system and prevent the absorption of heavy metals.

Keywords:

Antioxidant enzymes , Mn2+ , Ectomycorrhiza , Agaricus bisporus , Pistacia vera