Status and prospects of the application of root exudates in the restoration of polluted or desertated soil.

Ecological and environmental problems including heavy metal pollution have received increasing concerns. Given the shortage of physical and chemical remediation methods in high cost and secondary pollution, using plants and microorganisms for joint remediation of environment has become one of the most important strategies. Root exudates are an important medium for information and nutrient exchange between plants and soil. The roles of plant root exudates in remediation of polluted and degradated soil have been widely studied. In this review, we described the composition, secretion mechanism and functions of root exudates and summarized the functions of root exudate in heavy metal absorption, allelopathy, interaction between roots and rhizosphere microorga-nisms, and changes in soil physical and chemical properties. The progress, challenges and prospect of applying root exdudates and rhizosphere microorganisms in the remediation of ecology and environment have also been discussed. This review could provide theoretical support for the application of plant-microorganism based environmental remediation.