Aims Mercury pollution is a global environmental problem, and heavy metal hyperaccumulator and plant detoxicity is a promising method and current research area. Our objective was to study the halophyte Sesuvium portulacastrum to determine its Hg tolerance and accumulation in order to find a new phytoremediation plant.
Methods Cuttings of S. portulacastrum with one node and two opposite leaves were cultivated on 1/10 Hoagland nutrient solution supplemented with HgCl₂ (0, 5, 10, 25, 50 μmol·L^-1). After 30 d of treatment, we measured growth phenotype and physiological changes such as proline, chlorophyll, electrolyte leakage and Hg²⁺concentration.
Important findings Under low Hg²⁺concentration stress (10 μmol·L^-1), plants showed vigorous growth. The levels of proline, malondialdehyde and electrolyte leakage were similar to those in the untreated plants, but the chlorophyll content was increased. The species could accumulate Hg²⁺, especially in roots, which reached 33.9 μg·g^-1 DW with 50 μmol·L^-1 Hg²⁺ stress. The plants that accumulated 12.02 μg·g^-1 DW Hg²⁺in roots grew well. Thus, S. portulacastrum shows strong Hg²⁺ tolerance and accumulation.