Influence of sulfur and selenium application on wheat growth in arsenic-contaminated soil

Wheat could become poisoned when grown in soil with high arsenic (As) content. It is worthwhile to investigate the potential use of sulfur (S) and selenium (Se) for crop protection while detoxifying heavy metal(loid)s. In this study, a pot experiment was conducted under both single and combined application of the two elements. Their effects on wheat growth were analyzed based on As distribution in subcellular tissues and the variation in physiological and biochemical indicators. Despite wheat absorbing and enriching As under S and Se application, its growth status improved. Cell wall and vacuole sequestered majority of elevated As. Phytochelatins (PCs) content increased significantly in the roots, particularly when Se was applied alone. They could chelate with As using thiol groups. Superoxide dismutase (SOD) activity was found to be considerably lower in leaves and without any discernible increase in roots. Peroxidase (POD) activity in roots/stems and/or catalase (CAT) activity in stems increased, and exerted antioxidant effects. The leaf was well protected, and its chlorophyll content significantly increased. The application of S alone had a relatively weaker effect on reducing As content in grains, but the mixed application of Se could induce an inhibitory effect. [Display omitted] •As increased by applying S and Se was mainly enriched in cell wall and vacuole.•GSH and PCs contents increased in different tissue under certain applying conditions.•POD and CAT activities were enhanced in root and stem exerting antioxidant effects.•Applying S and Se enhanced stress on root, but chlorophyll content in leaf increased.•Se had effect on inhibiting As increase in grain under combined application with S.