The majority of terrestrial plant species establish below-ground interconnections via arbuscular mycorrhizal (AM) mycelium, thereby forming extensive common mycorrhizal networks (CMNs). CMNs serve as critical infrastructure for nutrient acquisition, mediating soil nutrient capture and distribution. In nitrogen-fixing plants, phosphorus (P) transport is particularly dependent on functional CMNs. The rapid expansion in graphene oxide (GO) production and its broad application have raised significant ecological concerns, particularly regarding its potential impacts on terrestrial ecosystems. Despite these concerns, the impact of GO on P transport dynamics within legume–arbuscular mycorrhizal fungi (AMF) symbioses remains critically scarce. This study established a symbiotic system using the model nitrogen-fixing legume Medicago sativa L. and AMF. This experimental system enabled a comprehensive assessment of GO effects on rhizosphere P mobilization, plant P acquisition, CMNs architecture, fungal community composition, and expression of key P transporter genes. Our results demonstrated that high GO concentrations significantly altered rhizosphere properties, increasing pH while reducing organic acid content and alkaline phosphatase activity. Furthermore, GO exposure significantly inhibited root growth, mycorrhizal colonization rates, and plant P acquisition efficiency. Additionally, GO exposure altered AMF community composition, reduced rhizosphere microbial diversity, and suppressed P metabolism gene expression. Specifically, 0.6% GO induced significant downregulation of MsCS and GigmPT by 83.5% and 62.3%, respectively. This indicates that GO impairs plant P uptake by disrupting the core pathway involving GigmPT and MsCS, triggering P stress in M. sativa. Collectively, these findings provide compelling evidence that GO exposure disrupts legume–AMF symbiotic integrity, ultimately impairing P transport efficiency.
Zhao et al. (2026) studied this question.