Fungus Neosartorya (Aspergillus) fischeri improves the fitness, tolerance and absorption of heavy metals in Typha latifolia

Heavy metal contamination is a global issue caused by anthropogenic activities leading to severe negative effects on the environment and human health. To address this problem, bioremediation strategies utilizing plants such as Typha latifolia and their symbiotic fungi have been adopted to remediate contaminated areas and mitigate the harmful effects of these pollutants. In this study, the endophytic fungus Neosartorya fischeri was isolated from the roots of T. latifolia plants growing in heavy metal-contaminated sites. N. fischeri colonized the epidermis and root cortex and showed high tolerance to toxic concentrations of silver (Ag) (1 mg/kg), copper (Cu) (60 mg/kg) and cadmium (Cd) (8 mg/kg). N. fischeri removed 8.7 % ± 0.5 % Cd from the medium, biosorbed 15.24 ± 0.2 mg/kg into its biomass, and enhanced the tolerance and bioaccumulation of Cd (184.18 ± 1.14 mg/kg) in plant roots. Moreover, N. fischeri produces siderophores, volatile compounds and solubilizes phosphates, which improve plant fitness. This was evidenced by a 28 % increase in photosynthetic pigments in T. latifolia plants colonized with N. fischeri. Additionally, N. fischeri inhibits the growth of important phytopathogens from the Fusarium genus. These findings highlight the important role of N. fischeri in enhancing the fitness and resilience of T. latifolia in hostile environments, demonstrating the potential of N. fischeri-T. latifolia association for the bioremediation of contaminated sites.