Effects of Arsenic on Nutrient Accumulation and Distribution in Selected Ornamental Plants

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).

Distribution and Speciation of Copper and Arsenic in Rice Plants (Oryza sativa japonica ‘Koshihikari’) Treated with Copper Oxide Nanoparticles and Arsenic during a Life Cycle

“…Therefore, total Cu uptake in SRs in treatments without As addition tended to reach relatively high maximum concentrations (Figure ). Meanwhile, As addition to the growth media disrupted normal homeostatic Cu regulation . Therefore, in treatments with As addition, Cu in SRs increased linearly with Cu in soil.…”

“…Meanwhile, As addition to the growth media disrupted normal homeostatic Cu regulation. 22 Therefore, in treatments with As addition, Cu in SRs increased linearly with Cu in soil. However, Cu uptake in MRs followed different patterns compared to that of 18-day SRs in our study.…”

“…Arsenic in the form of Na 2 HAsO 4 ·7H 2 O , (Sigma-Aldrich, Lot No. BCBM0939 V) was added at 0 and 10 mg/kg (near average As concentration in soils from Texas, USA) to an artificial soil mixture (60% Grainger clay soil, Catalog No.…”

Arsenic biotransformation potential of six marine diatom species: effect of temperature and salinity

“…These microbial species play a significant role in regarding biogeochemical cycling of As content by biotransformation in natural ecosystems 48 . As(V) and phosphate have similar physicochemical characteristics, and therefore algal species take up As(V) present in media via a phosphate transporter system 66 and As(V) biotransformation occurs inside the cell 67 . The competitive uptake between As(V) and PO 4 3− suggested a possible active toxic mode of As.…”

Freshwater phytoplankton: biotransformation of inorganic arsenic to methylarsenic and organoarsenic

“…This phenomenon happens due to the similar chemical properties of arsenate and phosphate. Arsenate can be actively taken up into the phytoplankton cells by the phosphate transporter pathway 40 and competing with phosphate uptake 41 . This competitive uptake between As V and phosphate in phytoplankton cells indicates the probable mode of action of the toxicity of As species.…”