FIGURE 7.

The mechanisms of Cd²⁺ uptake, translocation and sequestration in mulberry may be mediated by ZIP, NRAMP, HMA, and MTP transporters. (A) At the root level, ZIP and NRAMP transporters are involved in Cd²⁺ uptake. HMA and MTP transporters are involved in Cd²⁺ sequestration into vacuole. Vacuole efflux is mediated by NRAMP transporters. Intercellular transportation is mediated by ZIP, NRAMP, and HMA transporters. (B) At the stem level, loading of Cd²⁺ into xylem and unloading of Cd²⁺ from xylem are mediated by ZIP and HMA transporters. (C) At the leaf level, HMA and MTP transporters are involved in Cd²⁺ sequestration into vacuole. Vacuole efflux is mediated by NRAMP transporters. Intercellular transportation is mediated by ZIP, NRAMP, and HMA transporters.