Phytoremediation of zinc and cadmium: A study of arbuscular mycorrhizal hyphae

Arbuscular mycorrhizal fungi (AMF) are microscopic fungi naturally occurring in soil that form a symbiosis with plant roots, producing a highly elaborated hyphal mycelium network in soil.In vitro lab experiments were conducted to determine whether extraradical mycorrhizal hyphae are directly involved in sequestration and uptake of essential zinc and nonessential cadmium by plant roots under toxic concentrations. The research is a continuation of an initial study presented in the Spring 2005 issue of Remediation that focused on the specific role of AMF in the speciation of heavy metals. Thus, this article presents a more expanded view. Results show that zinc and cadmium heavy metals are sequestered and translocated to plant roots via extraradical AMF hyphae. Root/growth media accumulation factors reached 5:1 and 18:1 for zinc and cadmium, respectively. Phytoremediation of heavy metal–contaminated soils can be enhanced by mycorrhizal inoculation. © 2005 Wiley Periodicals, Inc.