title: Effects of transgenic fructan-producing potatoes on the community structure of rhizosphere and phyllosphere bacteria.
abstract: The rhizosphere and phyllosphere microbial communities of transgenic potatoes producing fructan were studied in comparison with isogenic controls and conventional varieties in a field release experiment over a period of 3 years. Population densities and 16S rRNA gene-based terminal restriction fragment length polymorphism (T-RFLP) analysis of the rhizosphere bacterial community only displayed the influence of annual and seasonal effects and the influence of field heterogeneity. In contrast, the T-RFLP analysis of the phyllosphere bacteria revealed in two of the 3 years significant differences in the community structure between the transgenic lines producing inulin and the other variants. This effect was studied in more detail through the analysis of bacterial isolates and a 16S rRNA gene clone library obtained from a transgenic line and the control. Both methods revealed a lower genetic diversity in the transgenic line and changes in the abundance of several bacterial groups. The isolates of the transgenic line were dominated by Bacilli, whereas most of the control isolates represented Actinobacteria. The clones were dominated by Proteobacteria, with main differences between both variants in Deltaproteobacteria, Bacilli and Bacteroidetes. However, all in all, the impact of the transgenic lines did not exceed the natural variability of the phyllosphere community structure on potato plants.
authors.affiliation: Leibniz-Zentrum für Agrarlandschaftsforschung (ZALF), Institut für Landschaftsstoffdynamik, Müncheberg, Germany.
authors.forename: Regina
authors.initials: R
authors.lastname: Becker
authors.forename: Undine
authors.initials: U
authors.lastname: Behrendt
authors.forename: Bernd
authors.initials: B
authors.lastname: Hommel
authors.forename: Siegfried
authors.initials: S
authors.lastname: Kropf
authors.forename: Andreas
authors.initials: A
authors.lastname: Ulrich
mesh_terms: D001419:Bacteria / Q000145:classification* / Q000235:genetics / Q000254:growth & development / Q000302:isolation & purification; D017753:Ecosystem; D005630:Fructans / Q000378:metabolism*; D008969:Molecular Sequence Data; D018517:Plant Roots / Q000382:microbiology*; D030821:Plants, Genetically Modified / Q000382:microbiology*; D012150:Polymorphism, Restriction Fragment Length; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012621:Seasons; D017422:Sequence Analysis, DNA; D012988:Soil Microbiology; D011198:Solanum tuberosum / Q000235:genetics / Q000378:metabolism* / Q000382:microbiology*
chemical_list: D005630:Fructans; D012336:RNA, Ribosomal, 16S