Submitted to: American Phytopathological Society Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 4/1/2017
Publication Date: 8/5/2017
Citation: Burbank, L.P., Stenger, D.C. 2017. Plasmid transfer by conjugation in Xylella fastidiosa.. American Phytopathological Society Annual Meeting. Available: https://apsnet.confex.com/apsnet/2017/meetingapp.cgi/Paper/5129. Interpretive Summary:
Technical Abstract: Recombination and horizontal gene transfer have been implicated in the adaption of Xylella fastidiosa (Xf) to infect a wide variety of different plant species. There is evidence that certain strains of Xf carry native plasmids equipped with transfer and mobilization genes, suggesting conjugation as a mechanism of horizontal gene transfer in some instances. Xf strains M23 (subspecies fastidiosa) and Riv5 (subspecies multiplex) carry two operons, tra and trb, on a 38kb plasmid. The tra and trb operons, which encode a conjugative Type IV secretion system, are also are present in Xf Dixon (subspecies multiplex) and several other isolates of subspecies fastidiosa. This suggests that certain Xf strains have the ability to transfer DNA via a conjugation mechanism, and that this transfer can occur between strains from different subspecies. Using either M23 (fastidiosa) or Dixon (multiplex) as the donor strain and Temecula (fastidiosa) as the recipient strain, plasmid transfer was characterized using the mobilizable broad host range vector pBBR5pemIK. Transfer of plasmid pBBR5pemIK was observed under in vitro conditions with both donor strains, and was dependent on both tra and trb operon functions. The possibility of plasmid transfer by conjugation in the natural environment would have implications for horizontal gene transfer between different strains of Xf that may be present in the same location and/or in the same vector or host.