[Oxidative stress-related signals and their regulation under Cd stress: A review.]

Contamination of heavy metal in soil causes several severe environmental problems. Cadmium is one of the most toxic metals to organisms. In plants, Cd toxicity often results in over-accumulation of reactive oxygen species (ROS), which causes oxidative damage to the plant organs. In this review, we discussed the processes of how Cd stress causes over-accumulation of ROS in plant and how plant recovers from the Cd-induced oxdative stress. We especially focused on the roles of signal, including nitric oxide (NO), calcium (Ca), plant hormones (e.g. auxin and abscisic acid) and mitogen-activated protein kinases (MAPKs), in above two processes. Our review may provide theoretical basis for future research on the mechanism of plant tolerating Cd stress.