Environmental pollution in relation to heavy metals is a worldwide issue. A large number of methods and techniques are utilized to overcome this problem. For this purpose, one of the most widely used techniques is phytoremediation, which is considered as a green technology. The mentioned technique involves the capability of some specific plants to absorb and accumulate heavy metal ions of plant parts. Phytoremediation has received increasing attention starting from the discovery of hyperaccumulator plants, which are able to concentrate high levels of specific metals in their aboveground harvestable biomass. The roots of Nicotiana species with the synthesis and release of nicotine and the precursor - nicotinamide as a significant heavy metal...