The influence of root endophytic fungus Piriformospora indica on growth, proline content, photosynthetic pigments and activity of antioxidant enzymes in wheat plant under 0.3 mM cadmium stress (Cd) was investigated. Cd exposure significantly reduced stem diameter, leaf area, chlorophyll a, carotenoid contents, activity of catalase (CAT) and ascorbate peroxidase (APX) in control plants, however, it notably increased malondialdehyde (MDA), proline and superoxide dismutase (SOD) activity.Inoculation of P. indica significantly increased the plant growth parameters, all photosynthetic pigments and proline contents. Also, the activity of CAT, APX and glutathione reductase (GR) were positivity influenced by fungus treatment. Under the stress, Cd contents markedly increased in stem and root organs (particularly at roots) but its accumulation was significantly decreased at both organs by P. indica. Our results suggest that the increased concentrations of antioxidant enzymes, and pigments and proline contents found in P. indica-inoculated plants may serve to protect wheat plants against oxidative damage, enhancing Cd tolerance.
