Phytoremediation of lead by a wild, non-edible Pb accumulator Coronopus didymus (L.) Brassicaceae

Abstract

Coronopus didymus was examined in terms of its ability to remediate Pb-contaminated soils. Pot experiments were conducted for 4 and 6?weeks to compare the growth, biomass, photosynthetic efficiency, lead (Pb) uptake, and accumulation by C. didymus plants. The plants grew well having no visible toxic symptoms and 100% survivability, exposed to different Pb-spiked soils 100, 350, 1500, and 2500?mg kg?1, supplied as lead nitrate. After 4?weeks, root and shoot concentrations reached 1652 and 502?mg Pb kg?1 DW, while after 6?weeks they increased up to 3091 and 527?mg Pb kg?1 DW, respectively, at highest Pb concentration. As compared to the 4?week experiments, the plant growth and biomass yield were higher after 6?weeks of Pb exposure. However, the chlorophyll content of leaves decreased but only a slight decline in photosynthetic efficiency was observed on exposure to Pb at both 4 and 6?weeks. The Pb accumulation was higher in roots than in the shoots. The bioconcentration factor of Pb was > 1 in all the plant samples, but the translocation factor was < 1. This suggested C. didymus as a good candidate for phytoremediation of Pb-contaminated soils and can be used for future remediation purposes. ? 2018 Taylor & Francis Group, LLC.