Fig. 6.

Tissue localization of co-inoculated strains in roots of potato seedlings stained with GUS for T168 and R182; counterstained with Victoria blue (Gram stain) for R170 and R181. A: (a) Localization of T168 at the base of the lateral root in the combined inoculation (T168+R170) that resulted in higher plant growth promotion confirmed by (b) the co-existence of both strains (7 d after the inoculation); and (c) the absence of T168, and localization of R181 at the base of the lateral root (7 d after the inoculation) in the combined inoculation (T168+R181), which showed lower plant growth promotion. B: (e) Localization of R182 that resulted in higher plant growth promotion (R182+R170) confirmed by intense infection to the root hairs by R182, and (f) R170 on the same primary root (7 d after inoculation). g: Localization of R182 in lower plant growth promotion (R182+R181) caused by the weak infection of R182 at the root hairs. h: Localization of R181 that resulted in lower plant growth promotion (R182+R181) revealed by the weak infection of R182 on root hairs.