Аннотация:The connection between sulphur (S) and selenium (Se) metabolism makes rapeseed (Brassica napus) an attractive candidate for Se fortification. Unfortunately, fertilizers may interfere with the availability of selenate (SeO42-) in numerous ways, including both soil and physiological processes. Experiments on two agricultural soils amended with SeO42- (32 μg Se kg−1 soil), sulphate and phosphate (each at three levels of supply) were established to elucidate the effect of these anions on the selenization efficiency. Maximal efficiency in Chernozem soil was roughly two-fold higher (455 μg Se kg−1 seed) than in Cambisol. Sulphate significantly decreased (up to 28%) the seed Se contents in Cambisol, while an enhancement (up to 33%) was found in Chernozem. In the Chernozem, the induction of collective S and Se translocation toward the seed more than compensated for any competition effects due to the highest sulphate supply. In Cambisol, plant Se distribution did not follow that of S as closely as in Chernozem. Phosphate did not significantly alter the fortification efficiency. Resistance of rapeseed proteins to protease hampered a quantitative investigation of changes in Se speciation under different S supplies. Nevertheless, protein-bound selenomethionine was the predominant Se storage form and traces of other Se species were also identified.
