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ABSTRACT: AimsThe objective of this study was to determine the relative importance of transpirational pull, Se speciation, sulfate and species
on Se accumulation by plants, in order to determine which of these factors must be considered in the future development of
models to predict Se accumulation by plants.
MethodsSeedlings of durum wheat (Triticum turgidum L. var durum cv ‘Kyle’) and spring canola (Brassica napus L. var Hyola 401) were grown hydroponically and exposed to SeO42- (selenate) with or without SO42- (sulfate), or to HSeO3- (biselenite) under different transpiration regimes altered through ‘low’ (~50%) or ‘high’ (~78%) relative humidity (RH).
Plants were harvested after 0, 8, 16, or 24h exposures, digested, and analyzed for Se by GFAAS.
ResultsAccumulation and distribution of Se by plants is dependent on plant species, Se speciation in the nutrient solution, SO42- competition, and transpiration regimes. Canola accumulated and translocated more Se than wheat. In wheat and canola, the
greatest accumulation and translocation of Se occurred when plants were exposed to SeO42- without SO42- compared to solutions of SeO42- with SO42- or HSeO32-. Wheat plants exposed to SeO42- and SO42- had an increased Se accumulation and translocation under increased transpiration rates than when exposed to SeO42- without SO42- or HSeO32-. On the other hand, increases in transpiration increased the translocation of Se to canola shoots when exposed to HSeO3- more than any other treatments.
ConclusionsOverall, our results suggest that plant species is the most important factor influencing Se accumulation and translocation,
but that these endpoints can be modified by climate and specific soil Se or S content. Models to predict accumulation of Se
by plants must consider all of these factors to accurately calculate the mechanisms of uptake and translocation.
Keywords
Brassica
–Element distribution–Ion accumulation–Trace element–Translocation–
Triticum
Plant and Soil 05/2012; 354(1):239-250. · 2.73 Impact Factor
