Abstract:
In the present study, the effect of phosphate ion and iron hydroxides (Fe-plaques) on the selective uptake of arsenic species by water fern (Salvinia natans L.) was investigated. The plants were grown for 5 days in aqueous Murashige and Skoog (MS) culture media modified in arsenic and phosphate concentrations. Arsenic accumulations in S. natans L. increased with the increase of arsenate and DMAA concentrations in the culture solutions. Compared to the control treatment, S. natans L. accumulated significantly higher amount of arsenic from phosphate-deficient solutions, when the source was arsenate. However, arsenic uptake was not affected significantly by phosphate, when the source was dimethylarsinic acid (DMAA). From solutions containing 100 µM of phosphate and 4.0 µM of either arsenate or DMAA, the S. natans L. accumulated 0.14 ± 0.02 and 0.02 ± 0.00 µmol (g dry weight)-1 of arsenic, respectively. In contrast, plants accumulated 0.24 ± 0.06 and 0.03 ± 0.00 µmol (g dry weight)-1 of arsenic from solutions containing 4.0 µM of either arsenate and DMAA in phosphate deficient conditions, respectively.
