title: Agrobacterium tumefaciens transfers single-stranded transferred DNA (T-DNA) into the plant cell nucleus.
abstract: Transferred DNA (T-DNA) is transferred as a single-stranded derivative from Agrobacterium to the plant cell nucleus. This conclusion is drawn from experiments exploiting the different properties of single- and double-stranded DNA to perform extrachromosomal homologous recombination in plant cells. After transfer from Agrobacterium to plant cells, T-DNA molecules recombined much more efficiently if the homologous sequences were of opposite polarity than if they were of the same polarity. This observation reflects the properties of single-stranded DNA; single-stranded DNA molecules of opposite polarity can anneal directly, whereas single-stranded DNA molecules of the same polarity first have to become double stranded to anneal. Judging from the relative amounts of single- to double-stranded T-DNA derivatives undergoing recombination, we infer that the T-DNA derivatives enter the plant nucleus in their single-stranded form.
authors.affiliation: Friedrich Miescher-Institute, Basel, Switzerland.
authors.forename: B
authors.initials: B
authors.lastname: Tinland
authors.forename: B
authors.initials: B
authors.lastname: Hohn
authors.forename: H
authors.initials: H
authors.lastname: Puchta