Examination of arsenic(III) and (V) uptake by the desert plant species mesquite (Prosopis spp.) using X-ray absorption spectroscopy

• Published in: Science of the total environment 2007-07, Vol.379 (2-3), p.249-255
• Main Authors: ALDRICH, M. V, PERALTA-VIDEA, J. R, PARSONS, J. G, GARDEA-TORRESDEY, J. L
• Format: Article
• Language: English
• Subjects: ABSORPTION SPECTROSCOPY; Applied sciences; ARSENIC; Arsenic - metabolism; Biodegradation, Environmental; Biological and medical sciences; Biotechnology; Decontamination. Miscellaneous; Earth sciences; Earth, ocean, space; Engineering and environment geology. Geothermics; Environment and pollution; ENVIRONMENTAL SCIENCES; Exact sciences and technology; Fundamental and applied biological sciences. Psychology; Industrial applications and implications. Economical aspects; MESQUITE; Miscellaneous; Other,OTHER; Plant Leaves - metabolism; Plant Roots - metabolism; Plant Stems - metabolism; Pollution; Pollution, environment geology; Prosopis; Prosopis - metabolism; Soil and sediments pollution; Soil Pollutants - metabolism; Spectrum Analysis; UPTAKE; X-RAY SPECTROSCOPY; X-Rays
• ISSN: 0048-9697; 1879-1026
• DOI: 10.1016/j.scitotenv.2006.08.053

This study describes the effects of Arsenic(III) and (V) on the growth and their uptake by the desert plant mesquite (Prosopis spp.). Seedlings were sown in agar-based medium containing a modified Hoagland's nutrient solution. After 1 week, the seedlings were transplanted to arsenic (As) treated agar media that contained 5 mgL(-1) of As either As(III) (As(2)O(3)) or As(V) (As(2)O(5)). The plants were harvested after 14 days of growth and sectioned into roots, stems, and leaves. After digestion, As concentrations in the roots, stems, and leaves were determined using inductively coupled plasma-optical emission spectroscopy (ICP-OES). Our results showed that the As concentrations from As(V) were significantly higher than the As concentrations from As(III) in all portions of the plant. Plants exposed to As(V) concentrated (mg As kg(-1) d wt) about 770+/-191, 326+/-94, and 119+/-18 in roots, stems, and leaves, respectively. X-ray absorption spectroscopy (XAS) showed that As(V) was reduced to As(III) inside the mesquite plant. In addition, greater than 90% of the As(III) found in the mesquite plants was bound to sulfur ligands in the roots, stems and leaves.