Metal from Plants

A research team from the University of Philippines, Los Baños has discovered an unusual plant that devours on nickel from soil to make a living. The plant accumulates up to 18,000 ppm (parts per million) of the metal into its leaves without running the risk of poisoning itself.

The plant has been named Rinorea niccolifera for its ability to absorb large amounts of nickel. This phenomenon of absorbing nickel in very high proportion is referred to as ‘Nickel Hyperaccumulation’. Only 0.5–1% of known plant species around the world native to nickel-rich soils are known to exhibit such ability. Niccolifera was discovered on the western part of Luzon Island in Philippines, an area with heavy metal rich soils. The 8 meter tall plant grows in nickel rich soils that cover less than 500 square kilometres of Luzon Island.

Hyperaccumulator plants have great potential to develop green technologies such as ‘phytoremediation’ and ‘phytomining’. Phytoremediation refers to the use of hyperaccumulator plants to absorb heavy metals accumulated in polluted soils and phytomining refers to using these plants to grow and harvest in order to recover commercially valuable metals in plant shoots from metal-rich sites.