heavy-metal tolerance

The ability of certain plants to grow in areas where the concentration of heavy metals, e.g. copper, lead, and zinc, is so high as to prevent the growth of most plants. Tolerance may be achieved by excluding the metal from the plant altogether but more usually results from detoxification, when the metal is converted to a harmless form. Some Agrostis species exhibit copper tolerance, restricting the metal to the roots and thus protecting the more sensitive shoots.