Figure 1.

Metal detection, plant signaling, and sequestration. Different transporters are involved in metal ion uptake. Elevated level of heavy metals triggers different signaling modules which transmit the signals inside cell, thus triggering defense response. The toxicity of these metals inside the cell is sequestered by metal chelators like phytochellatins and metallothionines. The chelated metals are then ultimately transported to the vacuoles with the help of metal transporters present on the vacuole membrane. PC, phytochelatins; MT, metallothionines; GSH, Glutathiones.