The natural transformation of the soil bacteria Pseudomonas stutzeri and Acinetobacter sp. by transgenic plant DNA strictly depends on homologous sequences in the recipient cells

Abstract

The nptII ‡ gene present in the genome of transgenic potato plants transforms naturally competent cells of the soil bacteria Pseudomonas stutzeri and Acinetobacter BD413 (both harboring a plasmid with an nptII gene containing a small deletion) with the same high efficiency as nptII ‡ genes on plasmid DNA (3U10 35 ^1U10 34 transformants per nptII ‡) despite the presence of a more than 10 6-fold excess of plant DNA. However, in the absence of homologous sequences in the recipient cells the transformation by nptII ‡ dropped by at least about 10 8-fold in P. stutzeri and 10 9-fold in Acinetobacter resulting in the latter strain in 9 1U10 313 transformants per nptII ‡. This indicated a very low probability of non-homologous DNA fragments to be integrated by illegitimate recombination events during transformation. ß