Main content area

A non-toxic polymer enhances sorghum-mycorrhiza symbiosis for bioremediation of Cd

Babadi, Milad, Zalaghi, Roya, Taghavi, Mehdi
Mycorrhiza 2019 v.29 no.4 pp. 375-387
Claroideoglomus etunicatum, cadmium, glomalin, mycorrhizae, mycorrhizal fungi, phosphorus, phytoremediation, plant tissues, polluted soils, pollution, polymers, rhizosphere, roots
In this study, the effect of a mycorrhizal symbiosis on the translocation of Cd from Cd-polluted soil to sorghum roots was investigated using rhizoboxes. A factorial experiment (two factors including fungus inoculation and Cd contamination) in a completely randomized design with three replicates was performed. In the rhizobox rhizosphere compartment, plants were cultivated in uncontaminated soil and mycorrhizal inoculation (inoculated with Claroideoglomus etunicatum or non-inoculated) was performed, and in the other compartment, the soil was contaminated with Cadmium (Cd) at one of three levels (0, 100 mg kg⁻¹ using a non-toxic organic polymer (poly (N-vinyl succinate))–Cd, or 100 mg kg⁻¹ using Cd-nitrate). Cd pollution resulted in a significant decrease in shoot dry weight (from 7.52 to 6.18 and 6.68 g pot⁻¹, from control to polymer-Cd and nitrate-Cd respectively), root mycorrhizal colonization (from 32.33% to 8.16% and 8.33%), shoot phosphorus concentration (from 3.14 to 2.80 and 2.76 g kg⁻¹), and soil carbohydrate (from 12.05 to 10.74 and 10.24 mg g⁻¹), and also resulted in significant increases in soil glomalin (from 595.55 to 660.52 and 690.39 μg g⁻¹). The use of mycorrhizal fungi increased the glomalin content of the soil and improved the studied parameters. The results revealed the key role of Claroideoglomus etunicatum in translocation of Cd in the rhizobox and also in precise control of Cd concentration of plant tissues (increase or decrease of them depending on Cd composition and Cd availability). Poly(N-vinyl succinate) increased Cd availability and Cd concentration of shoot tissue (5.19 mg kg⁻¹) compared to nitrate-Cd (3.68 mg kg⁻¹) and could be recommended for improving phytoremediation.