Little is known about effects of salinity and flooding on plant symbionts, including baldcypress trees (Taxodium distichum), the dominant trees in many swamp ecosystems of the Southeastern US. In this study, we used sequences from culturable fungal and bacterial endophytes to characterize their communities in the roots and leaves of baldcypress trees. We sampled from four sites with varying levels of salinity and flooding, to test the hypothesis that these abiotic factors correlate to differences in endophyte community structure. In a db-RDA model we tested the relative variation in microbial community structure due to site, date, average salinity, maximum salinity, average water level, minimum water level, maximum water level, average temperature, minimum temperature, maximum temperature, tidal amplitude and average time flooded.
Results/Conclusions
Both average salinity and flooding (average water level) contributed to endophytic community composition of leaves and roots combined. We found that diversity and abundance were higher in roots than in leaves, with leaf bacteria being almost negligible. Jean Lafitte, the most pristine site, had the highest diversity of endophytes. Our study demonstrates a connection between environmental variables, plant symbionts and a key restoration species and provides a foundation for future work investigating endophyte inoculations to increase the stress resilience of restoration planting