Fig. 1.

Microbial consortia naturally formed on the roots of Arabidopsis thaliana. Scanning electron microscopy pictures of root surfaces from natural A. thaliana populations showing the complex microbial networks formed on roots. a Overview of an A. thaliana root (primary root) with numerous root hairs. b Biofilm-forming bacteria. c Fungal or oomycete hyphae surrounding the root surface. d Primary root densely covered by spores and protists. e, f Protists, most likely belonging to the Bacillariophyceae class. g Bacteria and bacterial filaments. h, i Different bacterial individuals showing great varieties of shapes and morphological features