Sesuvium portulacastrum L. as a salt-tolerant phytostabilizer for lead (Pb) immobilization in saline agricultural soil

Importance of the Work: The increasing prevalence of heavy metals in agricultural soil threatens soil quality and poses serious risks to human health and requires eco-friendly and low-cost remediation solutions. Objectives: To evaluate the potential of Sesuvium portulacastrum L. to remediate lead- contaminated agricultural soil by assessing its growth response under different concentrations of Pb(NO3)2 exposure. Materials and Methods: The phytoremediation potential was evaluated during 70 d of the halophyte S. portulacastrum L. in Pb(NO3)2-contaminated agricultural soil, based on quantification of the lead distribution in plant tissues, the biological concentration factor (BCF) and the translocation factor (TF). Results: Pb accumulated predominantly in roots rather than shoots, with consistently low TF values (0.004–0.025), indicating limited root-to-shoot transport. Furthermore, the BCF values supported strong belowground enrichment, with BCF (root/soil) in the range 235.11–2,117.81 and BCF(shoot/soil) in the range 5.89–9.41 across treatments. Based on soil measurements, S. portulacastrum decreased soil Pb by 79.62%, 18.96% and 7.15% in soils initially amended with Pb(NO3)2 at 100 mg/kg dry weight (DW), 500 mg/kg DW and 1,000 mg/kg DW, respectively. Main finding: Overall, the findings supported the use of S. portulacastrum primarily for Pb phytostabilization and risk mitigation in saline soils.