Fig. 1.

Bacterial colonization of plant roots is a multistep process. A. Plants secrete photosynthetically fixed carbon into the rhizosphere forming chemical gradients, which chemotactically attract motile bacteria from the soil towards the root surface. Flagella and pili propel bacteria, allowing them to overcome any electrostatic repulsion at the root surface. B. Primary attachment results in weak reversible binding of single cells to the root surface. This is initially mediated by hydrophobic and electrostatic interactions and subsequently strengthened by proteinaceous appendages and species‐specific surface adhesins. C. Secondary attachment leads to strong irreversible binding of bacteria to the root surface, promoting microcolony formation at the initial site of attachment. This process is mediated by the production of cellulose fibrils and other species‐specific factors including polysaccharides extracellular proteins. Created with BioRender.com