The tolerance of plants to metal stress is the key prerequisite for an effective phytoremediation. Numerous biochemical reactions occur in plants under metal stress, so those plants with better ability to adjust to the toxicity effects are able to survive in impacted sites and are better candidates for phytoremediation purposes. Plants pose a wide range of mechanisms which may be involved in metal detoxification/tolerance processes, such as: binding of metals to cell wall and excretion of root exudates, restriction of metal movement to roots by mycorrhizas, reduced influx or even active efflux from the cytosol, reparation and protection of plazma membrane, chelation of metals in the cytosol and the compartmentation in the vacuole.