Molecular mechanism of plant response to copper stress: A review

Copper (Cu) is an essential trace element for plants, which plays an important role in photosynthesis, respiration and antioxidant system. It is a vital component of many enzymes, involved in various plant physiological and biochemical reactions. However, due to the extensive use of Cu-containing pesticides and the discharge of Cu-containing pollutants into the environment, Cu pollution has aroused people's attention owing to its deleterious effects on animals and plants. In plants, excess Cu can cause phytotoxicity by producing reactive oxygen species (ROS), inactivating enzymes and disintegrating protein structures. To cope with changes in Cu levels in the environment, plants try to precisely regulate Cu homeostasis through multiple regulatory mechanisms. In this paper, the biological function of Cu, the toxicity of excess Cu to plants, the transport process of Cu in plants and the mechanism of plant detoxification and tolerance to Cu stress are reviewed. Moreover, the potential research direction for better understanding the molecular regulatory mechanism of Cu stress tolerance in plants is proposed.