title: T-DNA integration in plants results from polymerase-θ-mediated DNA repair.
abstract: Agrobacterium tumefaciens is a pathogenic bacterium, which transforms plants by transferring a discrete segment of its DNA, the T-DNA, to plant cells. The T-DNA then integrates into the plant genome. T-DNA biotechnology is widely exploited in the genetic engineering of model plants and crops. However, the molecular mechanism underlying T-DNA integration remains unknown1. Here we demonstrate that in Arabidopsis thaliana T-DNA integration critically depends on polymerase theta (Pol θ). We find that TEBICHI/POLQ mutant plants (which have mutated Pol θ), although susceptible to Agrobacterium infection, are resistant to T-DNA integration. Characterization of >10,000 T-DNA-plant genome junctions reveals a distinct signature of Pol θ action and also indicates that 3' end capture at genomic breaks is the prevalent mechanism of T-DNA integration. The primer-template switching ability of Pol θ can explain the molecular patchwork known as filler DNA that is frequently observed at sites of integration. T-DNA integration signatures in other plant species closely resemble those of Arabidopsis, suggesting that Pol-θ-mediated integration is evolutionarily conserved. Thus, Pol θ provides the mechanism for T-DNA random integration into the plant genome, demonstrating a potential to disrupt random integration so as to improve the quality and biosafety of plant transgenesis.
authors: Department of Human Genetics, Leiden University Medical Centre, 2300 RC Leiden, The Netherlands.
authors: Maartje
authors: M
authors: van Kregten
authors: Department of Molecular and Developmental Genetics, Institute of Biology, Leiden University, 2333 BE Leiden, The Netherlands.
authors: Sylvia
authors: S
authors: de Pater
authors: Department of Human Genetics, Leiden University Medical Centre, 2300 RC Leiden, The Netherlands.
authors: Ron
authors: R
authors: Romeijn
authors: Department of Human Genetics, Leiden University Medical Centre, 2300 RC Leiden, The Netherlands.
authors: Robin
authors: R
authors: van Schendel
authors: Department of Molecular and Developmental Genetics, Institute of Biology, Leiden University, 2333 BE Leiden, The Netherlands.
authors: Paul J J
authors: PJ
authors: Hooykaas
authors: Department of Human Genetics, Leiden University Medical Centre, 2300 RC Leiden, The Netherlands.
authors: Marcel
authors: M
authors: Tijsterman
mesh_terms: D017360:Arabidopsis / Q000235:genetics* / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism; D004260:DNA Repair; D004269:DNA, Bacterial / Q000235:genetics* / Q000378:metabolism; D018744:DNA, Plant / Q000235:genetics* / Q000378:metabolism; D004259:DNA-Directed DNA Polymerase / Q000235:genetics* / Q000378:metabolism; D009154:Mutation; D000097462:DNA Polymerase theta
chemical_list: D029681:Arabidopsis Proteins; D004269:DNA, Bacterial; D018744:DNA, Plant; D004259:DNA-Directed DNA Polymerase; D000097462:DNA Polymerase theta; C036483:T-DNA; C511743:TEBICHI protein, Arabidopsis