Endophytic Bacillus subtilis Strain BS-2 Labeled with Green Fluorescent Protein Gene

Promoter 4412 of plasmid pGFP4412 was replaced by rpsD promoter of Bacillus subtilis strain 168 to obtain a new vector pS4GFP in which the gfp gene could strongly express under the control of rpsD promoter. Plasmid pS4GFP was transformed into the endophytic B. subtilis strain BS-2, and a fine gfp-labeled strain BS-2-gfp was obtained. The tests showed the strain could keep promoting plant growth and inhibiting plant pathogens. The strain also could appear bright green under blue light and the recombined plasmid was stable in the bacterial cells. The colonizing inside of cabbages with the strain showed that the bacteria could adhere to the surface of roots, and could be colonized in roots, stems and leaves. After inoculation for 50 days, the labeled bacteria could still be isolated from the cabbages. Fig 5, Ref 17