Fig. 6: Model of the role of the MdWRKY11-MdHMA5 pathway in the response to excess Cu in apple root cells.

Excess Cu-inducible MdWRKY11 binds to the promoter of MdHMA5, increased MdHMA5 transcription. Increased MdHMA5 promotes transmembrane transport Cu, which more efficiently decreases Cu levels in the cytoplasm