Fig. 2

Colonization analyses of strain D in tobacco roots. a Visualization of D colonizing tobacco plants at 14th day after inoculation under laser confocal microscopy. The GFP-labeled D cell suspensions (1 × 10⁸ CFU/mL) were added to the roots of 55-day-old tobacco (50 mL per plant). Sterile water was used as negative control. After inoculation for 14 days, the roots were collected and cut into 1 cm in length. Finally, the strain D colonized in tobacco roots were observed with the laser confocal microscopy. The D in tobacco roots was indicated by red arrow; scale bars represent 50 μm. b The population density of the D-gfp in tobacco roots. After inoculation for 0, 3, 6, 9, 12, 15, 20, 25, and 30 days, the roots were collected and homogenized in sterile water, and colony numbers were counted with dilution coated plate method. Data are presented as the mean ± SD based on three biological replicates; P-values were determined by LSD post-hoc test