Plant compartment and biogeography affect microbiome composition in cultivated and native Agave species.

Desert plants are hypothesized to survive the environmental stress inherent to these regions in part thanks to symbioses with microorganisms, and yet these microbial species, the communities they form, and the forces that influence them are poorly understood. Here we report the first comprehensive investigation of the microbial communities associated with species of Agave, which are native to semiarid and arid regions of Central and North America and are emerging as biofuel feedstocks. We examined prokaryotic and fungal communities in the rhizosphere, phyllosphere, leaf and root endosphere, as well as proximal and distal soil samples from cultivated and native agaves, through Illumina amplicon sequencing. Phylogenetic profiling revealed that the composition of prokaryotic communities was primarily determined by the plant compartment, whereas the composition of fungal communities was mainly influenced by the biogeography of the host species. Cultivated A. tequilana exhibited lower levels of prokaryotic diversity compared with native agaves, although no differences in microbial diversity were found in the endosphere. Agaves shared core prokaryotic and fungal taxa known to promote plant growth and confer tolerance to abiotic stress, which suggests common principles underpinning Agave-microbe interactions

Biogeography of aquatic hyphomycetes: current knowledge and future perspectives

Since Ingold’s (1942) initial description, mycologists have been interested in deciphering global distribution patterns of aquatic hyphomycetes, a group of fungi that play a key role in plant-litter decomposition in freshwaters. However, many questions remain largely unanswered. In this review, we used distribution data of morphospecies from studies throughout the world in an attempt to better understand the magnitude of global species richness, patterns of biodiversity and the extent of cosmopolitanism versus endemism. Sampling efforts have varied among geographic regions, and correlate significantly with species richness. Community similarity decreased with geographic or latitudinal distance. Species richness was highest at mid-latitudes (temperate streams), and high community similarities were found between geographically distant locations in similar climatic zones. Studies relying on morphotypes have undoubtedly provided relevant information on the geographic distribution of aquatic hyphomycetes. However, metagenomic approaches combining taxonomic, phylogenetic and functional diversity in coordinated surveys will be the best option to better decipher diversity patterns of these fungi and their functional roles at a global scale.This work was supported by FCT I.P. through the strategic funding UID/BIA/04050/2013. Financial support granted by the FCT to S. Duarte (postdoctoral fellowship SFRH/BPD/47574/ 2008) is also gratefully acknowledged.info:eu-repo/semantics/publishedVersio