Cadmium and copper stress induce a cellular oxidative challenge leading to damage versus signalling

Abstract

Contamination of soils with the potentially toxic elements cadmium (Cd) and copper (Cu) affects plant growth and crop production, and bioaccumulation in the food chain poses a threat to human health. Toxic levels of Cd or Cu both impose an oxidative challenge on plants, even though these trace elements have a different chemical (non-redox active versus redox-active) and biological (non-essential versus essential element) behaviour. Through (in)direct mechanisms, Cd and Cu cause an increased production of reactive oxygen species (ROS) as well as interference with redox-regulated compounds in different cellular compartments. This chapter highlights general and/or specific mechanisms of interference with the cellular redox homeostasis by Cd and Cu, which may be part of the sensing mechanism to these stresses. Furthermore, it emphasises the metal-induced oxidative challenge and its involvement in either cellular damage and/or downstream signalling responses.