AM fungi increase uptake of Cd and BDE-209 and activities of dismutase and catalase in amaranth (Amaranthus hypochondriacus L.) in two contaminants spiked soil.

Soil co-contaminated with cadmium (Cd) and decabromodiphenyl ether (BDE-209) is a widespread environmental problem, especially in electronic waste contaminated surroundings. Accumulation of Cd and BDE-209 in crops has possibly harmful effects on local human health. In order to assess the potential of arbuscular mycorrhizal (AM) fungi and amaranth (Amaranthus hypochondriacus L.) in remediation of soil co-contaminated with Cd and BDE-209, pot trials were performed to investigate interactive effects of AM fungi, Cd and BDE-209 on growth of amaranth, uptake of Cd and BDE-209, distribution of chemical forms of Cd and activities of antioxidant enzymes in shoots and dissipation of BDE-209 in soil. The present results showed that shoot biomass of non-mycorrhizal plants was significantly inhibited by increasing of Cd addition (5-15 mg kg-1), but were only slightly declined with BDE-209 addition (5 mg kg-1). The interaction of Cd and BDE-209 reduced the proportions of ethanol- and d-H2O-extractable Cd in shoots, consequently alleviated Cd toxicity to plants and enhanced root uptake of Cd and BDE-209. Inoculation of AM fungi resulted in significantly greater shoot biomass as well as higher concentrations of Cd and BDE-209 compared with non-mycorrhizal treatment. Moreover, AM fungi played a beneficial role in relieving oxidative stress on amaranth by increasing the activities of dismutase (SOD) and catalase (CAT) in shoots and significantly improved the dissipation of BDE-209 in soil. The present study suggested that combination of AM fungi and amaranth may be a potential option for remediation of Cd and BDE-209 co-contaminated soils.