Lead phytoextraction by Pelargoniumhortorum: Comparative assessment of EDTA and DIPA for Pb mobility and toxicity

Soil amendments like ethylene-diamine-tetraacetic-acid (EDTA) have extensively been used for enhancing lead (Pb) phytoextraction. But due to its toxic effects, environment friendly substitute is required. Therefore, the present study was conducted to investigate the effect of EDTA and Di-iso-propanol-amine (DIPA) to enhance Pb phytoavailability and uptake by Pelargonium hortorumalongwith comparative toxicities of both organic amendments. For this purpose, soil was spiked with Pb concentrations ( 0, 500, 750, 1000 and 1500 mg kg(-1)) and amended with EDTA and DIPA at dosage levels (0, 1.5, 3, 5, 7.5, 10 mmol kg(-1)) for plantation of Pelargonium hortorum. Soil samples were extractedwithMgCl(2), plant sampleswere acid digested and analyzed formetal content. Biomass and root/shoot length of Pelargoniumhortorumwas decreased with increase in concentration of Pb and chelating agents. Phytoavailability of Pb at 1500 mg kg(-1)with EDTA 10 mmol kg(-1) was 0.3-folds in comparison to DIPA at the same dosage. Pelargonium hortorum plants amended with EDTA and DIPA at 10 mmol kg(-1) with Pb 1000 mg kg(-1) were found to uptake Pb 5.3-fold and 2.5-folds, respectively in comparison to Pb 1000 mg kg(-1) alone. Pb uptake decreased at 1500 mg kg(-1) with both chelating agents. The EDTA alone and in combinationwith 1500mg Pb kg(-1) showedmaximumgenotoxicity by reducing the mitotic index and increasing themicronuclei formation. EDTA+Pb showedmaximumtoxicity followed by Pb andDIPA. Overall, 10 mmol kg(-1) of EDTA and DIPA performed better among all dosages in enhancing phytoavailability and uptake of Pb. DIPA showed less toxicity than that caused by EDTA, with comparable ability to promote Pb phytoextraction. (c) 2020 Elsevier B.V. All rights reserved.