Copper-Induced Responses in Different Plant Species

Copper (Cu)-induced stress caused adverse effects to plant growth and productivity thus considered as a severe threat for sustainable crop production. This article presents an overview of copper stress in plants. Copper participates in many physiological processes as a co-factor for catalysis of many metalloproteins; however, problem occurs when excess amount of copper is present in cells. The high concentration of copper suppresses biomass accumulation and linear plant growth. Copper affected root growth stronger than shoot growth. The reduced mobility of Cu in soil is due to its strong binding to organic and inorganic colloids, where it acts as a barrier to Cu toxicity in terrestrial plants. Excess of Cu inhibits a large number of enzymes and interferes with several aspects of plant biochemistry, including photosynthesis, pigment synthesis, and membrane integrity. So, the most important effect of copper toxicity is associated with the blocking of photosynthetic electron transport, leading to the production of radicals which start peroxidative chain reactions. Copper induces oxidative stress that involves induction of lipid peroxidation in the plant which further cause a severe damage to the cell membrane. High copper concentration can disturb the chloroplast ultrastructure by disturbing the photosynthetic process. Like chromium and iron, copper is also a redox metal that can have direct involvement in inducing oxidative stress in plants. In addition, Cu stress induced -production of reactive oxygen species is well recognized and controlled at both the production and consumption levels, through increased antioxidative systems.