Genetic Diversity and Potential of Cyanobacteria and Fungi Living on Arctic Liverworts

Liverworts often form symbiotic associations with fungi and cyanobacteria, yet the distribution and specificity of these relationships remain largely unexplored, particularly in Arctic environments. This study used metagenomic sequencing to investigate fungal and cyanobacterial communities associated with Arctic liverworts, analyzing photosynthetic parts of gametophytes and their rhizoids with attached soil separately. The results revealed that Ascomycota dominated the fungal community. The cyanobacterial community was primarily composed of heterocytous Nostoc and non-heterocytous filamentous Leptolyngbya, with Nostoc showing evidence of nitrogen fixation, especially in gametophytes, suggesting a potential role in enhancing nitrogen availability for the host. These findings underscore the ecological significance of liverwort-associated microorganisms in Arctic ecosystems, with microbial composition differing between upper and lower parts of plants, as well as between leafy and thalloid liverworts, indicating possible functional specialization.