Phytoremediation: Mechanisms and Adaptations. Mechanisms and Adaptations.

Metal contamination of soils is ubiquitous around the globe. Metals accumulate in the soils to toxic levels that may lead to accumulation of metals in plants to unacceptable levels. Metal accumulation is a subject of serious concern due to the threat to plant growth, soil quality, animal and human health. Cleaning up of the soils to remove metals is a current necessity, but it is a challenging task. Different technologies being used nowadays are ex situ which ensues in destruction of soil structure thus leaving it non-useable with poor vegetative cover. Growing plants to clean up the soils is a cost-effective and environmentally friendly alternative. Phytoremediation seems attractive due to non-invasive and non-destructive technology which leaves the soil intact and biologically productive. Plants use different adaptive mechanisms to accumulate or exclude metals, thus maintaining their growth. Accumulation and tolerance of metals by the plants is a complex phenomenon. Movement of metals across the root membrane, loading and translocation of metals through the xylem and sequestration and detoxification of metals at cellular and whole plant levels are important mechanisms adopted by accumulator plants. Understanding the mechanism involved in phytoremediation is necessary to effectively use this technique for metal-contaminated soils. This chapter discusses different mechanisms adopted by plants for remediation of metal-contaminated soils. © 2015 Elsevier Inc. All rights reserved