Changiz Zolfagharlou - School of Biological Sciences , Tarbiat Modares University , Tehran , Iran
Hasan Zare-Maivan - School of Biological Sciences , Tarbiat Modares University , Tehran , Iran

Heavy metals in plant reduce plant growth and performance potentials. Heavy metal also induce the formation of reactive oxygen species leading to cell damage. Plants face off heavy metal stress either by activating enzymatic and non-enzymatic antioxidant system such as, superoxide dismutase and subsequently, conversion of superoxide anion to hydrogen peroxide, followed up by peroxidase and catalase conversion of hydrogen peroxide to water or, mycorrhizal symbiosis. In this work, a greenhouse experiment, arranged in a randomized block design 2×4 factorial with four replicates, was conducted. Mycorrizal Barley(Hordeum vulgar), Rayhan var.Seedlings were treated with four concentrations of nickel(0,100,200 and 400 μg/g) added to the soil. Plans were allowed to grow for 12 weeks, after which, biometry of plant parts was done and antioxidant enzyme activites in mycorrhizal and control(non-mycorrhizal) rteatmens were determined. Results showed greater antioxidant activity in mycorrhizal than that of non-mycorrhizal plants. Also, it was determined that the accumulation of nickel in roots of mycorrihzal plants was higher than that of non-mycorrhizal plants

heavy metals, hordeum vulgar, antioxidants, vesicular arbuscular, barley, reactive oxygen species