GEOC 13 |
| Suzanne M. Reichman and David R. Parker Sr. Department of Environmental Sciences, University of California, Riverside, Riverside, 92521, CA 92507 |
| Phytosiderophores (including mugineic acids [MAs]) are amino acids that are universally excreted by the roots of grasses when subjected to Fe deficiency in alkaline soils. The MAs are thus frequently important for iron solubilization and uptake, including in a number of cereal and grain crops, but may also may be important in the acquisition of other essential metals (Zn, Cu) or in the mobilization of metals that pose health concerns (Cd). We are studying the metal-binding chemistry of MAs to clarify how effectively other metals can ìcompeteî with Fe(III); this in turn will disclose whether soil metals (Cd) are likely to be mobilized into the food chain by MAs, and whether excessive Cu or Ni could induce Fe deficiency in grasses. Using a strictly empirical approach to the pH-dependent solubility of metals, we have developed a geochemical modeling approach to simulate the metal-solubilizing properties of phytosiderophores under a range of soil contamination scenarios. |
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Chemistry of Metals in Terrestrial and Aquatic Systems
1:25 PM-5:05 PM, Sunday, March 28, 2004 Marriott -- Marquis NE, Oral
Division of Geochemistry |