Soil type shapes the diversity of protists living in intimate association with Arabidopsis thaliana
M. SAPP (1), S. Ploch (2), M. Bonkowski (3), L. Rose (1) (1) Heinrich-Heine University, Germany; (2) Senckenberg Biodiversity and Climate Research Centre, Germany; (3) University of Cologne, Germany

Plant-associated microorganisms have strong effects on their host's fitness. Thus, our perspective of plants as isolated entities has been revised, leading to the formulation of the concept of “holobiont”. Plant associations with bacterial and fungal communities have been recently circumscribed and are shaped by numerous variables, including soil type. Although some micro-eukaryotes are known plant-symbionts, their contributions to the "holobiont" are not well described. We describe cercozoan and oomycete taxa living in close association with the model plant Arabidopsis thaliana grown in two different soil types (loam and sand). Soil, roots and leaves were analyzed and complemented with surface sterilized plant organs to identify endophytic micro-eukaryotes. Cercozoan taxa were identified using 18S rRNA gene metabarcoding, whereas the Internal Transcribed Spacer (ITS1) and cytochrome c oxidase subunit 2 (cox2) were used to determine oomycete taxa. Paired-end sequencing included cercozoan and oomycete mock communities for all barcodes. 18S rRNA gene sequencing delivered 19 Mio, whereas cox2 and ITS1 sequencing delivered over 25 Mio reads. Subsequent analyses revealed a strong effect by soil type and differentiation of protist communities between plant organs. Our results highlight the importance of micro-eukaryotes for the plant holobiont and delivers new knowledge on the diversity of plant-associated micro-eukaryotes.

Abstract Number: P4-117
Session Type: Poster