Pectobacterium atrosepticum and Pectobacterium carotovorum Harbor Distinct, Independently Acquired Integrative and Conjugative Elements Encoding Coronafacic Acid that Enhance Virulence on Potato Stems
Preetinanda Panda, Bhanupratap R. Vanga, Ashley Lu, Mark Fiers, Peter C. Fineran, Ruth Butler, Karen Armstrong, Clive W. Ronson, Andrew R. Pitman
Abstract
Integrative and conjugative elements (ICEs) play a central role in the evolution of bacterial virulence, their transmission between bacteria often leading to the acquisition of virulence factors that alter host range or aggressiveness. Much is known about the functions of the virulence determinants that ICEs harbor, but little is understood about the cryptic effects of ICEs on their host cell. In this study, the importance of horizontally acquired island 2 (HAI2), an ICE in the genome of Pectobacterium atrosepticum SCRI1043, was studied using a strain in which the entire ICE had been removed by CRISPR-Cas-mediated genome editing. HAI2 encodes coronafacic acid, a virulence factor that enhances blackleg disease of potato stems caused by P. atrosepticum SCRI1043. As expected, deletion of HAI2 resulted in reduced blackleg symptoms in potato stems. A subsequent screen for HAI2-related ICEs in other strains of the Pectobacterium genus revealed their ubiquitous nature in P. atrosepticum. Yet, HAI2-related ICEs were only detected in the genomes of a few P. carotovorum strains. These strains were notable as blackleg causing strains belonging to two different subspecies of P. carotovorum. Sequence analysis of the ICEs in different strains of both P. atrosepticum and P. carotovorum confirmed that they were diverse and were present in different locations on the genomes of their bacterial host, suggesting that the cfa cluster was probably acquired independently on a number of occasions via chromosomal insertion of related ICEs. Excision assays also demonstrated that the ICEs in both P. atrosepticum and P. carotovorum are mobilized from the host chromosome. Thus, the future spread of these ICEs via lateral gene transfer might contribute to an increase in the prevalence of blackleg-causing strains of P. carotovorum.
This research output has an Altmetric Attention Score of 1. This is our high-level measure of the quality and quantity of online attention that it has received. This Attention Score, as well as the ranking and number of research outputs shown below, was calculated when the research output was last mentioned on 31 March 2016.
All research outputs
#18,449,393
of 22,858,915 outputs
Outputs from Frontiers in Microbiology
#19,367
of 24,871 outputs
Outputs of similar age
#220,314
of 301,001 outputs
Outputs of similar age from Frontiers in Microbiology
#410
of 545 outputs
Altmetric has tracked 22,858,915 research outputs across all sources so far. This one is in the 11th percentile – i.e., 11% of other outputs scored the same or lower than it.
So far Altmetric has tracked 24,871 research outputs from this source. They typically receive a little more attention than average, with a mean Attention Score of 6.3. This one is in the 9th percentile – i.e., 9% of its peers scored the same or lower than it.
Older research outputs will score higher simply because they've had more time to accumulate mentions. To account for age we can compare this Altmetric Attention Score to the 301,001 tracked outputs that were published within six weeks on either side of this one in any source. This one is in the 15th percentile – i.e., 15% of its contemporaries scored the same or lower than it.
We're also able to compare this research output to 545 others from the same source and published within six weeks on either side of this one. This one is in the 14th percentile – i.e., 14% of its contemporaries scored the same or lower than it.
