Effects of micro and nanoplastics on plant-assisted bioremediation for contaminated soil recovery: A review

Plant-assisted bioremediation (PABR) is a phytoremediation strategy for recovering contaminated soils, based on the synergistic interaction between plants and microorganisms in the rhizosphere. This sustainable approach enables the immobilization or extraction of heavy metal contaminants and degradation of organic pollutants, thereby helping to restore the quality and ecological balance of soils. However, in recent years, new and complex environmental challenges have been raised for the health of the soil-plant system due to the increasing spread and impacts of emerging contaminants such as micro and nanoplastics. In this regard, this article reviews the current state of studies focused on the synergistic effects between micro and nanoplastics and other contaminants (heavy metals and organic pollutants) on all those factors that promote PABR technologies in the soil. Particles can alter the chemical and physical properties of the soil, root and plant growth, microorganism composition, as well as the production of root exudates, which are key elements in stimulating microbial processes. Moreover, the co-presence in soils of heavy metals or organic pollutants with micro and nanoplastics may amplify synergistic effects and affect their bioavailability, interfering with bioremediation processes. Understanding how micro and nanoplastics can impact PABR is crucial for guiding future research towards PABR strategy optimisation and encouraging the adoption of innovative methodological approaches based on micro and nanoplastics.