Figure 1.

MAPK cascade and transcriptional factors in response to heavy metal stresses in plants. Heavy metal exposure triggers multiple signaling pathways such as NO, ROS and phytohormones. These signals interact and activate the MAPK cascade. Subsequently, MAPK cascade phosphorylates and activates related transcriptional factors including bZIP, WRKY, MYB, HSF and other transcriptional factors, which further induce the expression of defense genes, metal transporter genes, PCs, MTs, antioxidant related genes, etc. Finally, heavy metal tolerance or accumulation is enhanced in plants.