Phytoremediation is the use of plant-based technologies to decontaminate an area.
Most land plants can form a symbiotic relationship with fungi which is advantageous for both organisms. This relationship is called mycorrhiza. Researchers found that phytoremediation is enhanced by mycorrhizae. Mycorrhizal fungis symbiotic relationships with plant roots help with the uptake of nutrients and the plants ability to resist biotic and abiotic stress factors such as heavy metals bioavailable in the rhizosphere. Arbuscular mycorrhizal fungi (AMF) produce proteins that bind heavy metals and thereby decrease their bioavailability. The removal of soil contaminants by mycorrhizal fungi is called mycorrhizoremediation.
Mycorrhizal fungi, especially AMF, can greatly improve the phytoremediation capacity of some plants. This is mostly due to the stress the plants suffer because of the pollutants is greatly reduced in the presence of AMF, so they can grow more and produce more biomass. The fungi also provide more nutrition, especially phosphorus, and promote the overall health of the plants. The mycelium's quick expansion can also greatly extend the rhizosphere influence zone (hyphosphere), providing the plant with access to more nutrients and contaminants. Increasing the rhizosphere overall health also means a rise in the bacteria population, which can also contribute to the bioremediation process.
This relationship has been proven useful with many pollutants, such as Rhizophagus intraradices and Robinia pseudoacacia in lead contaminated soil, Rhizophagus intraradices with Glomus versiforme inoculated into vetiver grass for lead removal, AMF and Calendula officinalis in cadmium and lead contaminated soil, and in general was effective in increasing the plant bioremediation capacity for metals, petroleum fuels, and PAHs. In wetlands AMF greatly promote the biodegradation of organic pollutants like benzene-, methyl tert-butyl ether- and ammonia from groundwater when inoculated into Phragmites australis.