Survey of ABC transporter and metallothionein genes expressions in tall fescue inoculated with Funneliformis intraradices under Nickel toxicity

In plants, there are complex network of transport, chelation, and sequestration processes that functions in maintaining concentrations of essential metal ions in different cellular compartments, thus minimizing the damage caused by entry of non-essential metal ions into the cytosol. In the presence of toxic ones, arbuscular mycorrhizal (AM) fungi are able to alleviate metal toxicity in the plant. In this study the effect of an arbuscular mycorrhizal fungi Funneliformis intraradices on growth, Nickel tolerance, and ABC transporter and metallothionein expression in leaves and roots of tall fescue (Festuca arundinacea) plants cultivated in Ni polluted soil were evaluated. The fungi infected (M) and uninfected (M-) fescue plants were cultivated in soil under different Ni concentrations (0, 30, 90 and 180 ppm) for 3 months. Results demonstrated the positive effect of fungi colonization on the increase in growth and reduction in Ni uptake (90 and 180 ppm) and Ni translocation from roots to shoot of tall fescue under Ni stress. The results also demonstrated that the level of ABC transporterand metallothionein transcripts accumulation in roots was considerably higher for both M- and M plants compared to the control. Also, M plants showed less ABC and MET expression compared to the M- plants. These results demonstrated the importance of mycorrhizal colonization of F. intraradices in reduction of Ni transport from root to shoot of tall fescue which alleviates Ni-induced stress.