Selenium affects protein accumulation and its distribution in different protein fractions in developing wheat grains

The present study reveals the effect of selenium (Se) on different storage proteins accumulation and protein-bound Se in developing wheat grains. A greenhouse experiment was conducted on wheat grown in alkaline sandy loam soil treated with selenate-Se and selenite-Se ranging from 0 to 4 mg kg(-1). Selenium content increased significantly in various Se-treated plant tissues as compared to control at maturity. Total soluble proteins and different protein fractions, viz. albumin, globulins, prolamins and glutelins, decreased significantly in Se-treated wheat grains as compared to control. The amount of Se with reference to protein fraction was highest in the glutelin fraction, followed by prolamin, albumin and globulins. Electrophoretic analysis followed by densitometry revealed variations in the presence of polypeptide bands in different protein fractions at maturity. Fourier transform infra red spectra analysis revealed more flexibility and unfolding of structures with higher selenite dosage. The excess binding of Se to protein or amino acid may replace sulfhydryl groups of proteins, thus causing deleterious effects on normal protein form. However, higher concentration of protein-bound Se can be exploited for the fortification of Se-deficient foods in preparation of Se-enriched diets and various health supplements for populations deficient in Se.