Cadmium is a toxic metal. It occurs in trace concentrations in soil, water and air. Natural increases are mainly found around ore croppings and on serpentine soils. Concentration in the different compartments may enhance mainly due to industrial activities (ore mining, metal smelting, etc.) and agricultural practices (application of phosphate fertilizers and sewage sludge). Cadmium has a long biological half-life and may cause loss of function in living cells or cause sublethal stress and weaken the cell's response to an additional aggression, leading eventually to the cell's death and loss of tissue function. A good understanding of the stress responses of target tissue and of the functional state of the cells is fundamental. The goal of the present study is to investigate cadmium stress and toxicity in both plants and animals (more precisely mammals) and to compare the reactions at the cellular level. Focus will be on: - the defence mechanisms (complexation of cadmium by glutathione and related polypeptides, antioxidative defence, induced expression of proteins), - the localization of the protection mechanisms and distribution of cadmium, including the free cytosolic cadmium concentration, - the functional state of the cells (mitochondria). Combining different techniques and approaching the problem from different angles will lead to a more complete picture of the events taking place in cells when exposed to cadmium and to determine differences and similarities in responses in plant versus animal cells.