Nickel, cadmium and lead phytotoxicity and potential of halophytic plants in heavy metal extraction

Among heavy metals, nickel, cadmium and lead have received a particular attention not only as potent hazards to human health but also given their constant increase in the environment and bioaccumulation throughout the food-chain. In plants, these metals may either directly or indirectly cause a broad range of physiological and biochemical dysfunctions culminating ultimately in the sharp decline of crop production. Here, we present new insights regarding the mechanisms governing metal phytotoxicity. In addition, we emphasize the potential interest of halophytic plants in the framework of the phytoremediation approach which has emerged as an environmental-friendly technology contributing to the extraction of heavy metal from contaminated sites. Indeed, recent reports suggest that halophyte species could be more suitable for heavy metal extraction than glycophytes most frequently used so far.