Plant hormones are trace organic molecules that play important roles in plant growth, development and stress resistance. 24-epibrassinolide (Br24) and strigolactones (Gr24) were reported to alleviate the toxicity of heavy metals and restrict their translocation into plants. In this study, the effects of Br24 and Gr24 with or without iron plaque (IP) induction on the uptake and accumulation of cadmium (Cd) and arsenic (As) were examined in rice seedlings exposed to 6-day treatments of 2 mg L⁻¹ Cd or 5 mg L⁻¹ As in nutrient solution. The results showed that the growth of rice seedlings was decreased by Cd or As treatment, but Br24 or Gr24 with or without IP alleviated this adverse effect. Br24 or Gr24 can improve root length, average diameter, surface area, and volume, and tip the number of roots of rice plants with or without IP. Cadmium contents in rice shoots were significantly reduced by Br24 with IP or Gr24, but Cd accumulation and translocation from root to shoot were not decreased. The interaction of Br24 or Gr24 and IP dramatically increased As contents in rice root, and reduced As translocation from root to shoot. Br24 or Gr24 with IP induction significantly increased Fe content, but decreased the contents of mineral elements (Mn, Cu and Zn) in rice plants. Our results suggested that the exogenous application of Br24 or Gr24 could be advantageous against the toxicity of Cd or As, and a potential way to effectively inhibit Cd or As uptake by rice plants.
1. MEN C., LIU R.M., XU F., WANG Q.R., GUO L.J., SHEN Z.Y. Pollution characteristics, risk assessment, and source apportionment of heavy metals in road dust in Beijing, China. Science of the Total Environment, 612, 138, 2018.
2. GUO F.H., ZHONG Z.P. Pollution emission and heavy metal speciation from co-combustion of sedum plumbizincicola and sludge in fluidized bed. Journal of Cleaner Production, 179, 317, 2018.
3. PINTER I.F., SALOMON M.V., GIL R., MASTRANTONIO L., BOTTINI R., PICCOLI P. Arsenic and trace elements in soil, water, grapevine and onion in Jachal, Argentina. Science of the Total Environment, 615, 1485, 2018.
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