Research progress on remediation of pollutants in soil using plant-endophyte associations

Environmental pollution poses a serious threat to ecosystems and human health. In recent years, many scholars have found that endophyte-assisted phytoremediation has a particularly significant effect on the removal of pollutants in the environment and in the restoration of ecosystems. This article mainly describes the mechanisms and applications of endophyte-assisted phytoremediation, and highlights several methods of endophyte inoculation and the corresponding methods used to detect the colonization of these endophytes in the roots, stems, and leaves of host plants. The colonization dynamics of endophytes in the tissues of plants grown in contaminated soil and the application of the endophyte-plant system to enhance the remediation of areas contaminated with organic and heavy metal pollutants are also summarized. Furthermore, we describe the remedial mechanisms of endophyte and plant systems with respect to endophyte regulatory growth factors, biological nitrogen fixation and phosphorus dissolution, co-metabolizing organic compounds in host plants, the production of specific enzymes for degradation of organic compounds, the enhancement of plant resistance to heavy metals, and the reduction in heavy metal toxicity. Finally, we emphasize the fact that although there have been many studies on endophyte-assisted phytoremediation systems, the mechanisms underlying the interactions between hosts plants and endophytes have yet to be sufficiently elucidated. Moreover, there has been comparatively little research on the different aspects of endophyte-assisted phytoremediation and its application with respect to the treatment of water bodies and air pollution, which should become focuses of future research