Uptake of Cd or excess Cu by the plant is unavoidable, and beyond the capacity of chelation and sequestration mechanisms, these metals will impose an oxidative challenge to the plant. Cd and Cu can induce the oxidative challenge in a metal-specific way, through different mechanisms of ROS production and interference with specific redox-related compounds in different cellular compartments. Whether the oxidative challenge can be overcome depends on damage versus acclimation responses that may depend on the stress intensity. ROS can cause cellular damage but are also involved in signalling pathways triggering cellular responses. Measurements of changes in pro-and antioxidative components establish an oxida-tive stress signature that is different for Cd and Cu, due to metal-specific induction of signalling pathways that lead to, at least partly, differential responses. A more detailed characterisation of the oxidative stress signature will help us unravel the general and metal-specific underlying mechanisms of stress perception, signalling and responses caused by Cd and Cu.
Was this article helpful?