Different behavior of two strains of the arbuscular mycorrhizal fungus Rhizophagus intraradices on Senecio bonariensis Hook. & Arn. against heavy metal soil pollution: a pilot-scale test

Abstract

Arbuscular mycorrhizal fungi (AMF) have different biological mechanisms to alleviate stressful conditions in heavy metals (HMs) polluted soil. These mechanisms were widely assessed under controlled/greenhouse conditions, but scarcely studied at pilot or territory scale. The aim of this study was to evaluate the response of two Rhizophagus intraradices strains isolated from soils with different histories of pollution, in association with Senecio bonariensis plants, growing in an engineering vegetal depuration module filled with artificially HMs polluted substrate. Plants inoculated with GC3 strain uptook low amounts of HMs and translocated them to shoot biomass. Heavy metals (Mg, Zn, Mn, Cr, Cu and Ni) and macronutrients (Ca, K, S and P) were accumulated in roots of S. bonariensis when inoculated with GB8 strain, limiting their translocation to the shoot. Uninoculated plants showed high translocation of all studied elements to shoot tissues. Concluding, tested R. intraradices strains have exhibited different phytoprotection mechanisms under extremely toxic concentrations of HMs. Moreover, the development of the assay at such a high Technological Readiness Level represents a novel contribution in this field of study.

Keywords:

• Heavy metals
• Rhizophagus intraradices
• Senecio bonariensis
• vegetal depuration module

Acknowledgments

Authors acknowledge UBA, CONICET and ANPCyT for the financial support. To Juan Cerioni, Mauricio Visciglia, Sol Cerioni, Giuliana Tabanera, Julieta Labbé, Alejo Scarano, Luciana Cerchietti and Florencia Gonzalez for their technical assistance.

Disclosure statement

The authors report there are no competing interests to declare.

Statement of novelty

Our findings will contribute to the current knowledge about the response of arbuscular mycorrhizal fungi (AMF) in highly HM-polluted soils at a pilot scale assay (high TRL level). It will also demonstrate the importance of considering the intraspecific differences and the origin story of tested AMF strain when evaluating their response to stressful conditions.