Activity: Talk or presentation › Talk at conference or symposium › Science to science
Plant holobionts are known to harbour a wide diversity of microorganisms, such as bacteria and fungi, influencing plant nutrition, resistance to stress and fitness. Furthermore recent studies showed that actually Archaea also shape the microbiome of plants, but their functions and interactions with their hosts remained mostly unclear. To get a broader insight into the community structure, habitat preferences and functions of plant-associated Archaea, we compared 41 different agriculturally used plant-species from the mediterranean area, Austria and Eastern Africa as well as the vegetation of alpine raised bogs from upper Styria (Austria). Therefore we used a combined approach including 16S rRNA amplicon sequencing, whole metagenome shotgun sequencing and fluorescence in situ hybridization confocal laser scanning microscopy (FISH-CLSM). The highest relative abundances of Archaea were detected in the endosphere of olive trees (Olea europaea L.), with up to 67.3% of total reads, in dwarf shrubs (Vaccinium myrthillus and V. oxycoccus, with 33.0% and 31.7% respectively), and in the rhizosphere of sugar beets (Beta vulgaris L.) with 20.0%. Across all habitats the archaeal community structure was clearly dominated by Euryarchaeota, followed by the less abundant phylum of Crenarchaeota and Thaumarchaeota, except in O. europaea, where Thaumarchaeota were predominant. On plants, we observed signatures for putative adaptation mechanisms of Archaea for their hosts, including those for higher chemotaxis, nutrient cycling like CO2 fixation, stress response, especially against oxidative stress, archaeon stability, and possible plant growth promotion through auxin. These findings reveal a so far unobserved role of Archaea for plant holobionts.