Figure 3. hrpG inactivation allows intracellular invasion of nodule cells.

(A–C) CBM124ΔhrpG massively invaded plant cells intracellularly. A few bacteria were found in intercellular spaces ([B] arrow). Intracellular bacteria (bacteroids) were surrounded by a peribacteroid membrane ([C] black arrowhead) forming typical symbiosomes. Vesicles containing osmophile material ([C] white arrowhead) were often seen.