Frontiers in Microbiology (2017) 8 (573) - Pan-genomic analysis ...
Jerson Garita-cambronero, A. Palacio-Bielsa, M.M. López, J. Cubero (2017)
Pan-genomic analysis permitted to differentiate virulent and non-virulent strains of Xanthomonas arboricola and elucidate bacterial virulence factors
Frontiers in Microbiology 8 (573)
Abstract: Xanthomonas arboricola is a plant-associated bacterial species that causes diseases
on several plant hosts. One of the most virulent pathovars within this species is
X. arboricola pv. pruni (Xap), the causal agent of bacterial spot disease of stone fruit
trees and almond. Recently, a non-virulent Xap-look-a-like strain isolated from Prunus
was characterized and its genome compared to pathogenic strains of Xap, revealing
differences in the profile of virulence factors, such as the genes related to the type III
secretion system (T3SS) and type III effectors (T3Es). The existence of this atypical strain
arouses several questions associated with the abundance, the pathogenicity, and the
evolutionary context of X. arboricola on Prunus hosts. After an initial characterization
of a collection of Xanthomonas strains isolated from Prunus bacterial spot outbreaks
in Spain during the past decade, six Xap-look-a-like strains, that did not clustered
with the pathogenic strains of Xap according to a multi locus sequence analysis, were
identified. Pathogenicity of these strains was analyzed and the genome sequences of
two Xap-look-a-like strains, CITA 14 and CITA 124, non-virulent to Prunus spp., were
obtained and compared to those available genomes of X. arboricola associated with
this host plant. Differences were found among the genomes of the virulent and the
Prunus non-virulent strains in several characters related to the pathogenesis process.
Additionally, a pan-genomic analysis that included the available genomes of X. arboricola,
revealed that the atypical strains associated with Prunus were related to a group of
non-virulent or low virulent strains isolated from a wide host range. The repertoire of the
genes related to T3SS and T3Es varied among the strains of this cluster and those strains
related to the most virulent pathovars of the species, corylina, juglandis, and pruni. This
variability provides information about the potential evolutionary process associated to
the acquisition of pathogenicity and host specificity in X. arboricola. Finally, based in the genomic differences observed between the virulent and the non-virulent strains isolated from Prunus, a sensitive and specific real-time PCR protocol was designed to detect and identify Xap strains. This method avoids miss-identifications due to atypical strains of X. arboricola that can cohabit Prunus.
(original language: English)
Link to article at publishers website
Database assignments for author(s): Ana Palacio-Bielsa
Research topic(s) for pests/diseases/weeds:
identification/taxonomy
identification/taxonomy
Pest and/or beneficial records:
| Beneficial | Pest/Disease/Weed | Crop/Product | Country | Quarant.
|
|---|
