title: Fast and sensitive in vivo studies under controlled environmental conditions to substitute long-term field trials with genetically modified plants.
abstract: We introduce an easy, fast and effective method to analyze the influence of genetically modified (GM) plants on soil and model organisms in the laboratory to substitute laborious and time consuming field trials. For the studies described here we focused on two GM plants of the so-called 3rd generation: GM plants producing pharmaceuticals (PMP) and plant made industrials (PMI). Cyanophycin synthetase (cphA) was chosen as model for PMI and Choleratoxin B (CTB) as model for PMP. The model genes are expressed in transgenic roots of composite Vicia hirsuta plants grown in petri dishes for semi-sterile growth or small containers filled with non-sterile soil. No significant influence of the model gene expression on root induction, growth, biomass, interaction with symbionts such as rhizobia (number, size and functionality of nodules, selection of nodulating strains) or arbuscular mycorrhizal fungi could be detected. In vitro, but not in situ under field conditions, structural diversity of the bulk soil microbial community between transgenic and non-transgenic cultivars was determined by PLFA pattern-derived ratios of bacteria: fungi and of gram+: gram-bacteria. Significant differences in PLFA ratios were associated with dissimilarities in the quantity and molecular composition of rhizodeposits as revealed by Py-FIMS analyses. Contrary to field trials, where small effects based on the transgene expression might be hidden by the immense influence of various environmental factors, our in vitro system can detect even minor effects and correlates them to transgene expression with less space, time and labour.
authors.affiliation: Agrobiotechnology, Faculty of Agricultural and Environmental Sciences, University of Rostock, Germany.
authors.forename: Patricia
authors.initials: P
authors.lastname: Horn
authors.affiliation: Soil Science, Faculty of Agricultural and Environmental Sciences, University of Rostock, Germany.
authors.forename: André
authors.initials: A
authors.lastname: Schlichting
authors.affiliation: Soil Science, Faculty of Agricultural and Environmental Sciences, University of Rostock, Germany.
authors.forename: Christel
authors.initials: C
authors.lastname: Baum
authors.affiliation: Soil Science, Faculty of Regional and Environmental Sciences, University of Trier, Germany.
authors.forename: Ute
authors.initials: U
authors.lastname: Hammesfahr
authors.affiliation: Soil Science, Faculty of Regional and Environmental Sciences, University of Trier, Germany.
authors.forename: Sören
authors.initials: S
authors.lastname: Thiele-Bruhn
authors.affiliation: Soil Science, Faculty of Agricultural and Environmental Sciences, University of Rostock, Germany.
authors.forename: Peter
authors.initials: P
authors.lastname: Leinweber
authors.affiliation: Agrobiotechnology, Faculty of Agricultural and Environmental Sciences, University of Rostock, Germany. Electronic address: inge.broer@uni-rostock.de.
authors.forename: Inge
authors.initials: I
authors.lastname: Broer
mesh_terms: D060054:Agrobacterium; D001419:Bacteria / Q000145:classification; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D018533:Biomass; D004777:Environment; D018506:Gene Expression Regulation, Plant; D008957:Models, Genetic; D038821:Mycorrhizae / Q000145:classification; D010453:Peptide Synthases / Q000235:genetics / Q000378:metabolism; D010940:Plant Proteins / Q000032:analysis / Q000235:genetics; D018517:Plant Roots / Q000235:genetics / Q000254:growth & development / Q000382:microbiology; D030821:Plants, Genetically Modified / Q000235:genetics* / Q000382:microbiology*; D012231:Rhizobium / Q000145:classification; D012988:Soil Microbiology; D013172:Spores, Fungal; D013559:Symbiosis; D031306:Vicia / Q000235:genetics* / Q000378:metabolism / Q000382:microbiology*
chemical_list: D001426:Bacterial Proteins; D010940:Plant Proteins; C024250:cyanophycin; D010453:Peptide Synthases; C113257:cyanophycin synthase, bacteria
keywords: Agrobacterium rhizogenes; Bacteria-soil-plant interaction; Composite Vicia hirsuta; Rhizosphere ecology; Risk assessment; Root exudates; Soil