Emergence of a New Population of Rathayibacter toxicus: An Ecologically Complex, Geographically Isolated Bacterium.

Rathayibacter toxicus is a gram-positive bacterium that infects the floral parts of several Poaceae species in Australia. Bacterial ooze is often produced on the surface of infected plants and bacterial galls are produced in place of seed. R. toxicus is a regulated plant pathogen in the U.S. yet rel...

Full description

Saved in:
Bibliographic Details
Main Authors: Mohammad Arif, Grethel Y Busot, Rachel Mann, Brendan Rodoni, Sanzhen Liu, James P Stack
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2016-01-01
Series:PLoS ONE
Online Access:https://journals.plos.org/plosone/article/file?id=10.1371/journal.pone.0156182&type=printable
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1850189044922712064
author Mohammad Arif
Grethel Y Busot
Rachel Mann
Brendan Rodoni
Sanzhen Liu
James P Stack
author_facet Mohammad Arif
Grethel Y Busot
Rachel Mann
Brendan Rodoni
Sanzhen Liu
James P Stack
author_sort Mohammad Arif
collection DOAJ
description Rathayibacter toxicus is a gram-positive bacterium that infects the floral parts of several Poaceae species in Australia. Bacterial ooze is often produced on the surface of infected plants and bacterial galls are produced in place of seed. R. toxicus is a regulated plant pathogen in the U.S. yet reliable detection and diagnostic tools are lacking. To better understand this geographically-isolated plant pathogen, genetic variation as a function of geographic location, host species, and date of isolation was determined for isolates collected over a forty-year period. Discriminant analyses of recently collected and archived isolates using Multi-Locus Sequence Typing (MLST) and Inter-Simple Sequence Repeats (ISSR) identified three populations of R. toxicus; RT-I and RT-II from South Australia and RT-III from Western Australia. Population RT-I, detected in 2013 and 2014 from the Yorke Peninsula in South Australia, is a newly emerged population of R. toxicus not previously reported. Commonly used housekeeping genes failed to discriminate among the R. toxicus isolates. However, strategically selected and genome-dispersed MLST genes representing an array of cellular functions from chromosome replication, antibiotic resistance and biosynthetic pathways to bacterial acquired immunity were discriminative. Genetic variation among isolates within the RT-I population was less than the within-population variation for the previously reported RT-II and RT-III populations. The lower relative genetic variation within the RT-I population and its absence from sampling over the past 40 years suggest its recent emergence. RT-I was the dominant population on the Yorke Peninsula during the 2013-2014 sampling period perhaps indicating a competitive advantage over the previously detected RT-II population. The potential for introduction of this bacterial plant pathogen into new geographic areas provide a rationale for understanding the ecological and evolutionary trajectories of R. toxicus.
format Article
id doaj-art-36ae0474da4b4dc98b4487c8e67a7e24
institution OA Journals
issn 1932-6203
language English
publishDate 2016-01-01
publisher Public Library of Science (PLoS)
record_format Article
series PLoS ONE
spelling doaj-art-36ae0474da4b4dc98b4487c8e67a7e242025-08-20T02:15:42ZengPublic Library of Science (PLoS)PLoS ONE1932-62032016-01-01115e015618210.1371/journal.pone.0156182Emergence of a New Population of Rathayibacter toxicus: An Ecologically Complex, Geographically Isolated Bacterium.Mohammad ArifGrethel Y BusotRachel MannBrendan RodoniSanzhen LiuJames P StackRathayibacter toxicus is a gram-positive bacterium that infects the floral parts of several Poaceae species in Australia. Bacterial ooze is often produced on the surface of infected plants and bacterial galls are produced in place of seed. R. toxicus is a regulated plant pathogen in the U.S. yet reliable detection and diagnostic tools are lacking. To better understand this geographically-isolated plant pathogen, genetic variation as a function of geographic location, host species, and date of isolation was determined for isolates collected over a forty-year period. Discriminant analyses of recently collected and archived isolates using Multi-Locus Sequence Typing (MLST) and Inter-Simple Sequence Repeats (ISSR) identified three populations of R. toxicus; RT-I and RT-II from South Australia and RT-III from Western Australia. Population RT-I, detected in 2013 and 2014 from the Yorke Peninsula in South Australia, is a newly emerged population of R. toxicus not previously reported. Commonly used housekeeping genes failed to discriminate among the R. toxicus isolates. However, strategically selected and genome-dispersed MLST genes representing an array of cellular functions from chromosome replication, antibiotic resistance and biosynthetic pathways to bacterial acquired immunity were discriminative. Genetic variation among isolates within the RT-I population was less than the within-population variation for the previously reported RT-II and RT-III populations. The lower relative genetic variation within the RT-I population and its absence from sampling over the past 40 years suggest its recent emergence. RT-I was the dominant population on the Yorke Peninsula during the 2013-2014 sampling period perhaps indicating a competitive advantage over the previously detected RT-II population. The potential for introduction of this bacterial plant pathogen into new geographic areas provide a rationale for understanding the ecological and evolutionary trajectories of R. toxicus.https://journals.plos.org/plosone/article/file?id=10.1371/journal.pone.0156182&type=printable
spellingShingle Mohammad Arif
Grethel Y Busot
Rachel Mann
Brendan Rodoni
Sanzhen Liu
James P Stack
Emergence of a New Population of Rathayibacter toxicus: An Ecologically Complex, Geographically Isolated Bacterium.
PLoS ONE
title Emergence of a New Population of Rathayibacter toxicus: An Ecologically Complex, Geographically Isolated Bacterium.
title_full Emergence of a New Population of Rathayibacter toxicus: An Ecologically Complex, Geographically Isolated Bacterium.
title_fullStr Emergence of a New Population of Rathayibacter toxicus: An Ecologically Complex, Geographically Isolated Bacterium.
title_full_unstemmed Emergence of a New Population of Rathayibacter toxicus: An Ecologically Complex, Geographically Isolated Bacterium.
title_short Emergence of a New Population of Rathayibacter toxicus: An Ecologically Complex, Geographically Isolated Bacterium.
title_sort emergence of a new population of rathayibacter toxicus an ecologically complex geographically isolated bacterium
url https://journals.plos.org/plosone/article/file?id=10.1371/journal.pone.0156182&type=printable
work_keys_str_mv AT mohammadarif emergenceofanewpopulationofrathayibactertoxicusanecologicallycomplexgeographicallyisolatedbacterium
AT grethelybusot emergenceofanewpopulationofrathayibactertoxicusanecologicallycomplexgeographicallyisolatedbacterium
AT rachelmann emergenceofanewpopulationofrathayibactertoxicusanecologicallycomplexgeographicallyisolatedbacterium
AT brendanrodoni emergenceofanewpopulationofrathayibactertoxicusanecologicallycomplexgeographicallyisolatedbacterium
AT sanzhenliu emergenceofanewpopulationofrathayibactertoxicusanecologicallycomplexgeographicallyisolatedbacterium
AT jamespstack emergenceofanewpopulationofrathayibactertoxicusanecologicallycomplexgeographicallyisolatedbacterium