Assessing Gerbera jamesonii for phytoremediation: lead and zinc uptake, translocation, and impact on plant growth

Heavy metal contamination, particularly from lead (Pb) and zinc (Zn), poses significant ecological and public health concerns. This study evaluated metal uptake, translocation, and tolerance in Gerbera jamesonii through a controlled hydroponic experiment with five Pb and Zn treatments (0, 5, 10, 15, and 30 mg L−1), each replicated five times (n = 5), and a greenhouse pot experiment using five soil Pb treatments (S1–S5; 0–15202 mg kg−1), each replicated eight times (n = 8), arranged in a completely randomized design. In hydroponics, Pb was largely immobilized in roots, with bioconcentration factors (BCF) > 1 and translocation factors (TF) near zero at all concentrations, confirming minimal root-to-shoot movement and strong phytostabilization potential. Zn showed moderate accumulation in roots and shoots at low concentrations but caused toxicity and complete mortality at 30 mg L−1, indicating metal-specific physiological thresholds. In pot experiments, G. jamesonii displayed dose-dependent reductions in shoot and root biomass yet survived and continued accumulating Pb in roots under moderate contamination. Zn concentrations in plant tissues remained stable across soil treatments, suggesting efficient internal regulation. Overall, G. jamesonii effectively immobilizes Pb while exhibiting sensitivity to elevated Zn, supporting its suitability for Pb phytostabilization in contaminated soils, with further research needed to refine field-scale applications. This study is the first to integrate hydroponic and soil-based experiments to evaluate the metal-specific phytoremediation behavior of Gerbera jamesonii under Pb and Zn contamination. Unlike most phytoremediation studies focusing on food crops or hyperaccumulators, this work highlights a strictly ornamental, non-edible species within a phytostabilization and phytomanagement context. The findings demonstrate strong root-based Pb immobilization with negligible shoot translocation, while identifying clear Zn tolerance limits, providing new mechanistic and applied insight into the use of ornamental excluder plants for sustainable management of Pb-contaminated soils.