Plant Assisted Bioremediation of Heavy Metal Polluted Soils

Industrial and anthropogenic activities are the major reason for heavy metal pollutionHeavy metal pollution. To date, thousands of hectares of farmland globally and in India specifically have been contaminated by heavy metals. This has adversely affected the crop productivity, soil microbial diversity and eventually deteriorated the soil quality. Soil quality is closely associated with crop quality, human health and welfare. Therefore, the remediation of these metal-polluted soils becomes imperative. Conventional remediation methods like precipitation, oxidation/reduction, filtration, evaporation and adsorption etc. are energy demanding or require a large number of chemical reagents and are associated with possible production of secondary pollutants. Fortunately, some microorganisms with the capability to induce resistance to heavy metals, and reduce or adsorb them in non-toxic form can be used for possible bioremediation of polluted soils, thus representing an economical and environment-friendly remediation method. These microbes detoxify the heavy metals, clean up the environment and increase the soil fertility, but, the adsorbed or converted metal still remains in the soil is the problem associated with it. Phytoremediation can be another option for detoxification of heavy metal polluted soils. However, phytoremediation alone has its limitations. Hence, the most effective way of remediation of heavy metal polluted soils is an integrated approach that involves both plants and microbes. Understanding the whole mechanism of plant assisted bioremediationMechanism of plant assisted bioremediation along with bioavailability, uptake, translocationTranslocation, sequestration and different defence mechanisms will help to develop heavy metal stress-resistant cultivars and highly efficient plant species for phytoremediation in harmony with microflora through genetic engineering technologies. Hence, this chapter will provide an understanding of plant assisted bioremediation, the fate of heavy metals in plant and soil, different plant defence mechanisms and potential microflora for plant assisted bioremediation.