Redox plant metal uptake

Plants also vary with respect to their uptake of Se and their capacity to accommodate large, potentially toxic concentrations (Rosenfeld and Beath, 1964 Sors et al., 2005). Wetland plants have been reported to volatilize Se (Pilon-Smits et al., 1999 Lin and Terry, 2003 Wu, 2004), and factors influencing volatilization have been reviewed by Terry and Zayed (1994). As stated above, it has been suggested tlrat changes in redox conditions in the rhizosphere of some plants may influence Se speciation in soil. Some species accumulate Se in Se-rich soils, but not to the extent reported for hyperaccumulators of toxic metals such as Cd and Ni (Banuelos et al., 1997 Prasad and Freitas, 2003 Srivastava et al., 2005). There are few recent studies of Se uptake from soils with normal or deficient levels of Se, as would be the probable situation in the case of radio-Se pollution, but the data have been reviewed comprehensively by Coughtrey et al. (1983) and Ihnat (1989). 

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