Influence of Arbuscular Mycorrhizal Fungi and Iron Oxide Magnetic Nanoparticles on Maize Growth and Fe-Uptake

A greenhouse pot experiment was established to investigate the effects of Glomus caledonium on maize (Zea mays) plants under differential levels (0.1, 1.0, and 10.0 mg·kg^-1) of nano-iron oxide magnetic nanoparticles (Fe₃O₄) artificially added soils. The results indicate that the high (10.0 mg·kg^-1) application of nano-Fe₃O₄ significantly decreased (P<0.05) plant biomass of maize, root mycorrhizal colonization rate and plant N, P, Ca, Zn concentration, but significantly increased (P<0.05) shoot Fe concentration. Compared to the corresponding non-AM fungi-inoculated treatment, inoculating Glomus caledonium significantly increased (P<0.05) root Fe concentration and individual Fe acquisition of maize plants, but significantly decreased (P<0.05) shoot Fe concentration, that eventually significantly increased (P<0.05) plant biomass of maize with the high nano-Fe₃O₄ applied treatment. These results indicate that AM fungi could alleviate the toxicity of nano-Fe₃O₄ to plants by enhancing Fe partition in roots and reducing the translocation of Fe by maize plants.