Role of arbuscular mycorrhizal fungi in phytoremediation of heavy metals and effects on growth and biochemical activities of wheat (Triticum aestivum L.) plants in Zn contaminated soils

Abstract

The increase of metals pollution in soil is a worldwide problem that affects the health of humans and environment. The use of green technology such as phytoremediation is one of the environmental friendly techniques, in which plants and other microbes are used to reduce the level of metals contaminants in soil and lower its uptake towards plants tissues. Studies report that a number of cereal crops such as wheat accumulates heavy metals in their tissues at higher concentrations. In the present study, we investigated the effect of arbuscular mycorrhizal fungi (AMF) on wheat plants with the increase of three different zinc (Zn) concentrations (0, 100, 300 and 900 mgkg^-1) in soil. After eight weeks of pot experiment, roots colonization, shoot and root biomass, growth, heavy metals contents and other biochemical parameters were assessed. The results indicate mycorrhizal inoculated (M) plants performed better at moderate Zn concentrations (300 mgkg^-1). In AMF associated plants, Zn contents were lower in shoot part of plants as compared to roots. In addition, higher P contents were observed in M treated plants as compared to NM plants. The decrease of nutrient contents, growth and antioxidant enzymatic activities were found at the highest applied Zn concentrations (900 mgkg^-1). Results indicate that AMF inoculum exhibit different tolerance strategies to reduce metals toxicity in host plants. The effective mycorrhizal symbiosis was observed with wheat plants and can be useful for phytostabilization of Zn contaminated soils which can play a vital role in the increase of food productivity and safety.

Key words: Wheat, arbuscular mycorrhizal fungi, phosphorus, nutrient contents, antioxidant enzymes.