A Functional Bacterium-to-Plant DNA Transfer Machinery of Rhizobium etli

Different strains and species of the soil phytopathogen agrobacterium possess the ability to transfer and integrate a segment of dna (t-dna) into the genome of their eukaryotic hosts,which is mainly mediated by a set of virulence (vir) genes located on the bacterial ti-plasmid that also contains the t-dna. to date,agrobacterium is considered to be unique in its capacity to mediate genetic transformation of eukaryotes. however,close homologs of the vir genes are encoded by the p42a plasmid of rhizobium etli; this microorganism is related to agrobacterium,but known only as a symbiotic bacterium that forms nitrogen-fixing nodules in several species of beans. here,we show that r. etli can mediate functional dna transfer and stable genetic transformation of plant cells,when provided with a plasmid containing a t-dna segment. thus,r. etli represents another bacterial species,besides agrobacterium,that encodes a protein machinery for dna transfer to eukaryotic cells and their subsequent genetic modification. © 2016 lacroix,citovsky.