Aldrich M V, Peralta-Videa J R, Parsons J G, Gardea-Torresdey J L
Environmental Science and Engineering Program, Department of Chemistry, University of Texas at El Paso, 500 W University Ave., El Paso, TX 79968-0513, USA.
Sci Total Environ. 2007 Jul 1;379(2-3):249-55. doi: 10.1016/j.scitotenv.2006.08.053. Epub 2006 Oct 19.
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.
本研究描述了三价砷和五价砷对沙漠植物牧豆树（牧豆树属）生长及砷吸收的影响。将幼苗播种在含有改良霍格兰营养液的琼脂培养基中。1周后，将幼苗移植到经砷处理的琼脂培养基中，该培养基含有5 mgL(-1)的砷，分别为三价砷（As(2)O(3)）或五价砷（As(2)O(5)）。生长14天后收获植株，并将其分为根、茎和叶。消化后，使用电感耦合等离子体发射光谱法（ICP-OES）测定根、茎和叶中的砷浓度。我们的结果表明，在植物的所有部位，五价砷的浓度显著高于三价砷的浓度。暴露于五价砷的植物在根、茎和叶中积累的砷（mg As kg(-1)干重）分别约为770±191、326±94和119±18。X射线吸收光谱法（XAS）表明，五价砷在牧豆树植物体内被还原为三价砷。此外，在牧豆树植物中发现的三价砷有超过90%与根、茎和叶中的硫配体结合。
