Genome sequence of Ensifer adhaerens OV14 provides insights into its ability as a novel vector for the genetic transformation of plant genomes
1 Department of Crop Science, Teagasc Crops Research Centre, Oak Park, Carlow, Ireland
2 UCD Earth Institute and UCD School of Biology and Environmental Sciences, University College Dublin, Belfield, Dublin 4, Ireland
3 Animal and Bioscience Research Department, Animal and Grassland Research and Innovation Centre, Teagasc, Grange, Dunsany, Co. Meath, Ireland
4 Current address: Institute of Biological, Environmental and Rural Sciences, Aberystwyth University, Aberystwyth, Ceredigion SY23 3FL, UK
5 Current address: Carlsberg Research Centre, Gamle Carlsberg Vej 4-10, 1799 Copenhagen V, Denmark
BMC Genomics 2014, 15:268 doi:10.1186/1471-2164-15-268Published: 7 April 2014
Recently it has been shown that Ensifer adhaerens can be used as a plant transformation technology, transferring genes into several plant genomes when equipped with a Ti plasmid. For this study, we have sequenced the genome of Ensifer adhaerens OV14 (OV14) and compared it with those of Agrobacterium tumefaciens C58 (C58) and Sinorhizobium meliloti 1021 (1021); the latter of which has also demonstrated a capacity to genetically transform crop genomes, albeit at significantly reduced frequencies.
The 7.7 Mb OV14 genome comprises two chromosomes and two plasmids. All protein coding regions in the OV14 genome were functionally grouped based on an eggNOG database. No genes homologous to the A. tumefaciens Ti plasmid vir genes appeared to be present in the OV14 genome. Unexpectedly, OV14 and 1021 were found to possess homologs to chromosomal based genes cited as essential to A. tumefaciens T-DNA transfer. Of significance, genes that are non-essential but exert a positive influence on virulence and the ability to genetically transform host genomes were identified in OV14 but were absent from the 1021 genome.
This study reveals the presence of homologs to chromosomally based Agrobacterium genes that support T-DNA transfer within the genome of OV14 and other alphaproteobacteria. The sequencing and analysis of the OV14 genome increases our understanding of T-DNA transfer by non-Agrobacterium species and creates a platform for the continued improvement of Ensifer-mediated transformation (EMT).