Two-year field monitoring shows little evidence that transgenic potato containing ABF3 significantly alters its rhizosphere microbial community structure

Background: Plants over-expressing Arabidopsis ABF3 (abscisic acid-responsive element-binding factor 3) have enhanced tolerance to various environmental stresses, especially drought. Using terminal restriction fragment length polymorphism (T-RFLP) analysis, we compared the rhizosphere-associated structures of microbial communities for transgenic potato containing this gene and conventional “Jopoong” plants. Results: During a 2-year field experiment, fungal richness, evenness, and diversity varied by year, increasing in 2010 when a moderate water deficit occurred. By contrast, the bacterial richness decreased in 2010 while evenness and diversity were similar in both years. No significant difference was observed in any indices for either sampling time or plant line. Although the composition of the microbial communities (defined as T-RF profiles) changed according to year and sampling time, differences were not significant between the transgenic and control plants. Conclusions: The results in this study suggest that the insertion of ABF3 into potato has no detectable (by current T-RFLP technique) effects on rhizosphere communities, and that any possible influences, if any, can be masked by seasonal or yearly variations.