Arbuscular mycorrhizal fungi in heavy metal highly polluted soil in the Riachuelo river basin Roxana P. Colombo; Matias E. Benavidez; Laura Fernandez Bidondo; Vanesa A. Silvani; María J. Bompadre; Marina Statello; Maria V. Scorza; Adalgisa Scotti; Alicia M. Godeas;