Effect of soil heavy metal contamination on arbuscular mycorrhizal fungal diversity in an e-waste dismantling area

Abstract:

[Background] The environmental problem caused by soil heavy metal (HM) contamination upon e-waste dismantling is becoming increasingly serious. Arbuscular mycorrhizal (AM) fungi can colonize plant root and enhance the ability of plant to resist environmental stresses, with important ecological function and application potency. [Objective] To study soil HM contamination effects on the community structure and diversity of AM fungi in e-waste dismantling areas, and to identify AM fungal species which have strong resistance to HM contamination. [Methods] A total of 12 soil samples were collected from a typical e-waste dismantling site and the surrounding areas in Taizhou city, Zhejiang province. The 18S rRNA gene of soil AM fungi was sequenced by pyrosequencing, and the relative abundances of operational taxonomic units (OTUs) and the diversity indices were calculated. [Results] Soil AM fungi in the investigated area are mainly composed by Archaeosporales, Glomerales and Diversisporales, with the dominant order of Glomerales. Although soil AM fungal diversity indices had no significant correlations with the concentrations, and the comprehensive pollution and potential ecological risk indices of HMs, the relative abundance of Rhizophagus vesiculiferus-like OTU positively correlated to all above pollution parameters of HMs. [Conclusion] R. vesiculiferus may have extremely strong resistance to HM contamination, providing technical basis for the treatment of contaminated soil caused by e-waste dismantling in the future.