Due to the persistency of soil organic pollutants and their potential risk to the eco environment and human health, there is an increasing urge to remediate organics polluted soils. Biodegradation of soil organic pollutants by rhizosphere microorganisms has been a research focus. Arbuscular mycorrhizal fungi are ubiquitous symbiotic microbes associated with plants. Compared with bacteria and actinomycete,mycorrhizal fungi are more tolerant to organic pollutants in soil. For instance, some of them can use most persistent organic pollutants (POPs) as exclusive carbon source for obtaining energy. This paper reviewed the research into the relationships among mycorrhizal fungi, plant and organic pollutants during last two decades. The mechanisms of biodegradation of soil POPs by mycorrhizal fungi fall into three categories:(1) Direct degradation: mycorrhizal fungi can excrete enzymes to decompose organic pollutants to low molecular organic matter, carbohydrate, water and other non toxic matter to obtain energy; (2) Co-metabolism: mycorrhizal fungi use readily available or low molecular organics as primary carbon and energy source, and use high molecular organic pollutants as the second substrate; (3) Degradation in the mycor-rhizosphere: the quantities of microorganisms in mycor-rhizosphere soil are up to 1000 times more than those in the bulk soils. Degradation of organic pollutants will be enhanced as a result of joint contribution from microbes living in the mycor-rhizosphere. The inoculation of extraneous microbes such as nitrogen-fixing bacteria and genetically engineered bacteria can be used as a means of mycor rhizosphere control to improve bioremediation efficiency. For instance, the introduction of nitrogen fixing bacteria will change the proposition of the bacteria in mycor rhizosphere soil and reduce C/N to improve the activities of soil microbes. Gene engineering can also be used to modify indigenous bacteria so that they could not only adapt to the local soil conditions easily, but also enhance capability to degrade organic pollutants in soils.
