Plant and microbe interactions in the phytoremediation of heavy metal contaminated soils

Abstract

In this study, phytoremediation; the amount of heavy metal (Cu) uptake by plant species, host plants’ symbiosis potential with two different species of arbuscular mycorrhizal fungi (AMF), interaction between AMF and host plants for sequestration of Cu available in the soil, as well as generation of glomalin-related soil protein (GRSP). Heavy metal concentrations were 100, 500 and 1000 ppm. For phytoremediation, two commercial crops (sorghum and sunflowers) which are widely cultivated in majority of agricultural fields in Turkey were used as host plants. The results showed a strong variability in sunflower and sorghum plants colonized with both AMF species in terms of GRSP (0.6–11.2 mg g−1 and 0.2-10.75 mg g−1), respectively. Cu content (29.34–249.86 mg kg−1 for the total Cu in sunflower and 12.06– 73.97 mg kg−1 for sorghum rhizosphere colonized by G. mosseae (up to 60%) were observed. This study provides evidence on the role of the plant microbe interactions in Cu sequestration as well as Glomalin generation related to heavy metal stimulation. Findings suggest highly efficient mechanism for AMF to mitigate stress leading to stabilization of polluted soils. Results also provide a new suggestion on the contribution of Glomalin in copper sequestration in polluted soils.