| dc.description.abstract | In Miami, Florida, 95% of residential and 33% commercial soils exceed the Florida Department of
Environmental Protection goals for cleanup of arsenic contamination. Ornamental plants have not
been fully investigated as a mechanism for phytoremediation of low level As contaminated soil.
This study evaluates nutrient uptake by ornamental plants grown in a hydroponic system containing
concentrations of 0, 10, 20, 30, 40, 50 or 70 uM As (0.0, 0.75, 1.5, 3.0, 3.75, 5.25 mg∙L−1 As,
respectively). Uptake of Ca, K, Mg and Mo was likely influenced by the toxic effect of As on root
functions. Arsenic had little effect on Ca, K and Mg transportation to the shoot at any but the highest
As exposure rate. Tissue P concentration was similar to or higher than that found in controls
and As competition with P uptake occurred at 70 uM As only. Tissue sulfur initially increased then
subsequently decreased at 70 uM As where uptake could no longer supply enough S for both detoxification
and normal metabolic needs. The effect of As on plant B was likely a result of membrane
leakage and overall tissue damage leading to a reduction in transpiration. Arsenic induced
Fe deficiency was likely the primary cause of chlorosis; however, As induced reduction in Zn, Mn
or Mg contributed to chlorosis. Copper use in cellular functions was very efficient; nevertheless, Cu
deficiency was one of the initial effects of As toxicity. Differences in mineral uptake reflect the
plant’s attempt to detoxify As (i.e. increase in S for S-containing As chelators), mitigate damage to
the cell (i.e. Ca to repair leaky menbranes) or continue cellular functions through alternative
pathways (i.e. Fe superoxide dismutases to replace the function of Cu/ZnSOD). | en_US |
