Distribution patterns of endophytic fungi in different intertidal plant communities within a tropical mangrove forest in South China

Fungi play a crucial role in the growth of mangrove plants in various intertidal zones. However, our knowledge of the endophytic fungi in mangroves is limited. In this study, we analyzed the distribution patterns of endophytic fungi in true mangroves (TM), mangrove associates (MA), and other plants (OP) in a tropical mangrove forest. The results showed that Lulwoana, Fusarium, and Aspergillus were the predominant endophytic fungal taxa in TM, MA, and OP, respectively. Non-metric multidimensional scaling demonstrated significant differences in the endophytic fungal community structure among different intertidal plant communities, highlighting the plant-mediated selection of endophytic fungi. In addition, tides and plant species may affect endophytic fungal communities by altering soil properties. The colonization of arbuscular mycorrhizal fungi (AMF) and dark septate endophytes (DSE) was higher in MA, possibly because of variations in soil pH and available phosphorus content. Phylogenetic analyses indicated that family Diversisporaceae and Par1 (Paraglomeraceae) were exclusively found in the mangrove associates, whereas Glome4 (Glomeraceae) and Par2 (Paraglomeraceae) were observed only in the TM. These results support the high variation in AMF communities among the different intertidal plant communities. This study emphasizes the critical role of tides and plant species in shaping the composition of endophytic fungal communities, which has significant implications for the conservation and restoration of mangrove ecosystems.