Toxic interactions of metal ions (Cd²⁺, Pb²⁺, Zn²⁺ and Sb³⁻) on <i>in vitro</i> biomass production of ectomycorrhizal fungi

Abstract

A number of ectomycorrhizal (ECM) fungi, from sites uncontaminated by toxic metals, were investigated to determine their sensitivity to Cd²⁺ , Pb⁺² , Zn²⁺ and Sb^3- , measured as an inhibition of fungal biomass production, Isolates were grown in liquid media amended with the metals, Individually (over a range of concentrations) and in combination (at single concentrations) to determine any significant interactions between the metals. Significant interspecific variation in sensitivity to Cd²⁺ and Zn²⁺ was recorded, while Pb²⁺ and Sb^3- individually had little effect. The presence of Pb²⁺ and Sb^3- in the media did however, amcliorate Cd²⁺ and Zn²⁺ toxicity in some circumstances. Interactions between Cd⁺² and Zn⁺² were investigated further over a range of concentrations. Zn²⁺ was found to significantly ameliorate the toxicity of Cd²⁺ to three of the four isolates tested. The influence of Zn²⁺ varied between ECM species and with the concentrations of metals tested.