title: Homology-dependent DNA transfer from plants to a soil bacterium under laboratory conditions: implications in evolution and horizontal gene transfer.
abstract: DNA transfer was demonstrated from six species of donor plants to the soil bacterium, Acinetobacter spp. BD413, using neomycin phosphotransferase (nptII) as a marker for homologous recombination. These laboratory results are compatible with, but do not prove, DNA transfer in nature. In tobacco carrying a plastid insertion of nptII, transfer was detected with 0.1 g of disrupted leaves and in oilseed rape carrying a nuclear insertion with a similar quantity of roots. Transfer from disrupted leaves occurred in sterile soil and water, without the addition of nutrients. It was detected using intact tobacco leaves and intact tobacco and Arabidopsis plants in vitro. Transfer was dose-dependent and sensitive to DNase, and mutations in the plant nptII were recovered in receptor bacteria. DNA transfer using intact roots and plants in vitro was easily demonstrated, but with greater variability. Transfer varied with plant genome size and the number of repeats of the marker DNA in the donor plant. Transfer was not detected in the absence of a homologous nptII in the receptor bacteria. We discuss these results with reference to non-coding DNA in plant genomes (e.g., introns, transposons and junk DNA) and the possibility that DNA transfer could occur in nature.
authors.affiliation: Laboratoire de Biologie de la Rhizosphere, Institut National de la Recherche Agronomique, 78026 Versailles, France. tepfer@versailles.inra.fr
authors.forename: David
authors.initials: D
authors.lastname: Tepfer
authors.forename: Rolando
authors.initials: R
authors.lastname: Garcia-Gonzales
authors.forename: Hounayda
authors.initials: H
authors.lastname: Mansouri
authors.forename: Martina
authors.initials: M
authors.lastname: Seruga
authors.forename: Brigitte
authors.initials: B
authors.lastname: Message
authors.forename: Francesca
authors.initials: F
authors.lastname: Leach
authors.forename: Mirna Curkovic
authors.initials: MC
authors.lastname: Perica
mesh_terms: D000150:Acinetobacter / Q000235:genetics* / Q000302:isolation & purification; D001483:Base Sequence; D005075:Biological Evolution; D018744:DNA, Plant / Q000235:genetics*; D022761:Gene Transfer, Horizontal; D010944:Plants / Q000235:genetics* / Q000382:microbiology; D012689:Sequence Homology, Nucleic Acid
chemical_list: D018744:DNA, Plant