Association between a liverwort and arbuscular mycorrhizal fungi: a promising strategy for the phytoremediation of polycyclic aromatic hydrocarbons

Abstract

Soil contamination with polycyclic aromatic hydrocarbons (PAHs) represents a major environmental challenge and requires cost-effective and environmentally friendly remediation technologies. Phytoremediation, enhanced by arbuscular mycorrhizal fungi (AMF), is an effective and extensive technique for PAHs remediation, although, its application with non-vascular plants, is largely unexplored. This study investigates the role of the AMF Rhizophagus irregularis in the uptake and bioaccumulation of anthracene in the liverwort Lunularia cruciata under in vitro conditions. The thallus and the AMF were able to absorb and bioaccumulate anthracene in the cell wall and spores, hyphae and arbuscules respectively. Our results indicate that the liverwort–fungus system employs multiple phytoremediation mechanisms, including phytoaccumulation and phytostabilization. At intermediate contamination levels, the fungal symbiont enhanced contaminant accumulation in the plant, whereas at higher contamination levels, this effect diminished, suggesting a potential limitation in fungal-mediated uptake under extreme conditions. These findings highlight the potential of AMF symbiosis in liverworts for developing biological tools for PAHs remediation, emphasizing the dependence on pollutant concentration for the effectiveness of phytoremediation.