Knockdown of BTS may provide a new strategy to improve cadmium-phytoremediation efficiency by improving iron status in plants.

The identification of the key genes related to cadmium (Cd) tolerance and accumulation is a major element in genetically engineering improved plants for Cd phytoremediation. Owing to the similarity between the ionic hydrated radius of Cd2+ and Fe2+, this study investigated how the Cd tolerance and accumulation of Arabidopsis plants was affected by the knockdown of BTS, a gene that negatively regulates Fe nutrition. After exposure to 40 μM Cd, the BTS-knockdown mutant, bts-1, exhibited greater Fe nutrition and better growth than wild-type plants. In addition, the Cd concentration in both roots and shoots was approximately 50% higher in the bts-1 mutant than in wild-type plants. Consequently, the bts-1 mutant accumulated approximately 100% and 150% more Cd in the roots and shoots, respectively, than wild-type plants. Further study showed that Fe removal from the growth medium and inhibition of the Fe transporter gene, IRT1, removed the differences observed in the growth and Cd concentration of the bts-1 and wild-type plants, respectively. These results demonstrated that BTS knockdown improved Cd tolerance and accumulation in plants by improving Fe nutrition; thus, the knockdown of BTS via biotechnological pathways may represent a valuable strategy for the improvement in the efficiency of Cd phytoremediation.