Effects of Rainfall and Drought on the Functional and Taxonomic Diversity of Cultivable Yeasts Associated With <i>Bromelia laciniosa</i> From a Brazilian Tropical Dryland

The phyllosphere is a crucial interface for plant-environment interactions, hosting a diverse microbial community, including yeasts. This community affects the host's fitness and can act as a plant resilience booster. Nonetheless, abiotic factors can have a significant impact on the microbial community. Therefore, this work aims to investigate the potential effects of rain and drought on the taxonomic and functional diversity of epiphytic yeasts associated with Bromelia laciniosa leaves in the Caatinga, a tropical dryland in South America. A total of 262 isolates were obtained. Based on their D1/D2 region of the LSU gene rRNA sequences, the isolates were identified as belonging to 76 species of yeasts and yeast-like fungi, including 53 Basidiomycetes and 23 Ascomycetes. Furthermore, 23 species (ca. 30% of the total) are possible new species. Most of the variables related to rainfall and drought did not affect the yeast taxonomic diversity. Furthermore, the impact of rain and drought on the community composition differs between functional and taxonomic diversities, which may suggest a decoupling between these dimensions. The functional and taxonomic structure of the yeast community in the Caatinga is complex, and rain and drought alone are not the absolute factors governing its dynamics. Additionally, the functional traits may provide valuable insights into the behavior of the yeast community in bromeliads and help predict the effects of dry-wet cycles on the leaf-inhabiting yeast community, as well as potential impacts on the host.