Fig. 3

Locations of the endophytic bacteria resided in the tissue of the roots of inoculated Hybrid Pennisetum, which were imaged by SEM. a Control, no endophytic bacteria were detected in the tissues of non-inoculated host plants; b Treated plants, 3 days after inoculation, cells of endophytic bacteria were detected in the root cortex; c Treated plants, 7 days after inoculation; cells of endophytic bacteria were detected mostly in the root cortex and a few in the xylem vessel; d Inoculated plants, 14 days after inoculation, a large number of bacterial cells were already found in the xylem vessel. RC root cortex; X xylem vessel; E cell of endophytic bacteria