Microbial Community Analysis in the Rhizosphere of a Transgenic Tomato that Overexpresses 3-Hydroxy-3-methylglutaryl Coenzyme A Reductase

The impact of overexpression of the 3-hydroxy-3-methylglutaryl coenzyme A reductase gene on microbial diversity in the rhizosphere of a transgenic tomato was examined using a ribosomal intergenic spacer analysis (RISA) and a terminal restriction fragment length polymorphism (T-RFLP) analysis of two functional bacterial genes (bacterial chitinase and nifH genes). While the overall profiles of both RISA and T-RFLP revealed high similarity between the transgenic and non-trangenic tomato, several polymorphic DNAs were detected as differential bands in both the qualitative and quantitative evaluations. Sequence analysis suggested that differential bands cloned in RISA showed low levels of similarity to known species but were most likely derived from uncultured microbes. The phylogenetic analyses of two differential bands cloned in the T-RFLP analysis of the chitinase and nifH genes indicated that these bands belonged to Streptomyces like chitinase group and cyanobacterial nifH group, respectively.