Endophytic bacteria (dark red cells) colonize any region within the epidermis of the plant root,and they can reside in apoplastic intercellular spaces and the xylem vessel apoplast.
In general, the endophytes invade the internal plant tissues through sites of injury in the epidermis, root tips, and root cracks formed at the sites of lateral root emergence.
Some endophytic bacteria can spread to distant plant organs (stem, leaves, seeds, and fruits).