Using a plant hormone and a thioligand to improve phytoremediation of Hg-contaminated soil from a petrochemical plant

► Mercury uptake by crop plants grown on contaminated soil from a petrochemical site. ► Plant hormone increased biomass production while thioligand increased Hg uptake. ► The combination of cytokinine and ammonium thiosulfate showed synergistic effects on Hg phytoextraction. ► The labile Hg fraction in soil was significantly removed by Brassica juncea and Helianthus annuus.