Journal of Microbiology

Research Support, Non-U.S. Gov'ts

Impact of cry1AC-Carrying Brassica rapa subsp. pekinensis on Leaf Bacterial Community: Young Tae Kim , Kang Seon Lee , Moon Jung Kim , Seung Bum Kim; J. Microbiol. 2009;47(1):33-39. Published online February 20, 2009; DOI: https://doi.org/10.1007/s12275-008-0254-4

Abstract: The effects of Chinese cabbage (Brassica rapa subsp. pekinensis) carrying cry1AC derived from Bacillus thuringiensis (Bt) on leaf bacterial community were examined by analyzing the horizontal transfer of transgene fragments from plants to bacteria. The effect of plant pathogenic bacteria on the gene transfer was also examined using Pseudomonas syringae pathovar. maculicola. The frequency of hygromycin-resistant bacteria did not alter in Bt leaves, though slight increase was observed in Pseudomonas-infected Bt leaves with no statistical significance. The analysis of bacterial community profiles using the denaturing gradient gel electrophoresis (DGGE) fingerprinting indicated that there were slight differences between Bt and control Chinese cabbage, and also that infected tissues were dominated by P. syringae pv. maculicola. However, the cultured bacterial pools were not found to contain any transgene fragments. Thus, no direct evidence of immediate gene transfer from plant to bacteria or acquisition of hygromycin resistance could be observed. Still, long-term monitoring on the possibility of gene transfer is necessary to correctly assess the environmental effects of the Bt crop on bacteria.

Denaturing Gradient Gel Electrophoresis Analysis of Bacterial Community Profiles in the Rhizosphere of cry1AC-carrying Brassica rapa subsp. pekinensis: Sera Jung , Semi Park , Daeha Kim , Seung Bum Kim; J. Microbiol. 2008;46(1):12-15.; DOI: https://doi.org/10.1007/s12275-007-0190-8

Abstract: The effect of genetically modified (GM) Brassica rapa subsp. pekinensis (Chinese cabbage) expressing Bt toxin gene (cry1AC) to the rhizosphere bacterial community was examined using the denaturing gradient gel electrophoresis (DGGE) fingerprinting method. From the visual comparison of the DGGE profiles, there were no significant differences between the profiles of Bt and control rhizosphere in both Suwon and Yesan samples. From the sequence analysis of the individual bands, Sphingomonas sp. of Alphaproteobacteria and several actinobacterial members were identified as the main bacterial taxa in both Suwon and Yesan samples. In the multiple correspondence analysis, no clear separation between Bt and control rhizosphere was seen in both Suwon and Yesan datasets. The profiles of bulk soils were separated from those of rhizosphere. The DGGE fingerprinting analyses indicated that Bt crops did not significantly alter the genetic composition of rhizosphere bacterial communities.

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