Role of Plants in Heavy Metals Remediation

Soil pollution by heavy metals has become one of the significant environmental concerns facing the world today. This not only reduces soil fertility but also affects human health through food chain. Thus, to safeguard soil resources, it is necessary to seek effective approaches for preventing soil degradation and restoring soils polluted by heavy metals. Phytoremediation is a very promising remediation technique that reduces or stabilizes heavy metals and some other soil pollutants using plants. There are five basic types of phytoremediation, each with a different mechanism for remediating heavy metal-polluted soils: phytoextraction, phytostabilization, phytovolatization, phytodegradation and phytofiltration. However, their successful application is usually limited due to slow and incomplete remediation by plants. Therefore, improving plant performance is a crucial factor for developing highly effective phytoremediation. The efficiency of phytoremediation can be improved through using organic or inorganic amendments, chelating and acidifying agents, using microbial assisted or transgenic plant-mediated phytoremediation and applying plant growth regulators. Besides, the combination of different phytoremediation approaches could offer new opportunities to improve the effectiveness of phytoremediation.