1,721,060 research outputs found
Draft Genome Sequence of Two Strains of Xanthomonas arboricola Isolated from Prunus persica Which Are Dissimilar to Strains That Cause Bacterial Spot Disease on Prunus spp.
Full text linkThe draft genome sequences of two strains of Xanthomonas arboricola, isolated from asymptomatic peach trees in Spain, are
reported here. These strains are avirulent and do not belong to the same phylogroup as X. arboricola pv. pruni, a causal agent of
bacterial spot disease of stone fruits and almonds.This work was supported financially by the Instituto Nacional de Investigación
y Tecnología Agraria y Alimentaria (INIA) project RTA2014-
00018-CO2-01.Publishe
Erwinia amylovora: Características generales. métodos de diagnóstico de la enfermedad e identificación de E. amylovora
Full text linkEl género Erwinia, que debe su nombre a la memoria del fitopatólogo Erwin F. Smith, se creó inicialmente para agrupar a las enterobacterias asociadas a las plantas, Gram negativas, bacilares, no formadoras de esporas y móviles (Winslow et al., 1920). Por ello, los miembros de este género incluían además enterobacterias saprofitas ecológicamente asociadas a plantas, así como
patógenos oportunistas del hombre y los animales (Brenner, 1984). Esta heterogeneidad de especies fue la causa de que el género Erwinia fuera objeto de varias reclasificaciones. Finalmente, gracias al avance de las técnicas moleculares, las especies del género Erwinia se clasificaron en cuatro grupos filogenéticos basados en la comparación de secuencias del ADN ribosómico
16S (Hauben et al., 1998). El grupo I (género Erwinia) representa a las verdaderas erwinias e incluye diversas especies, que producen necrosis o marchitamientos en plantas, o que pueden ser epifitas. Erwinia amylovora es la especie tipo de este género. El grupo II (actuales géneros Pectobacterium y Dickeya) agrupa especies que originan podredumbres blandas en
un amplio rango de hospedadores debido a su gran actividad pectolítica. El grupo III (actual género Brenneria y la especie Dickeya paradisiaca) incluye varias especies que afectan a plantas leñosas produciendo generalmente chancros y exudados. El grupo IV (género Pantoea) contiene especies que son saprofitas o patógenos más o menos frecuentemente oportunistas de plantas, animales y del hombre. Entre ellas destaca la antigua Erwinia herbicola, actualmente denominada Pantoea agglomerans, frecuentemente asociada en rosáceas a E. amylovora
Draft genome sequence of Xanthomonas arboricola pv. pruni strain Xap33, causal agent of bacterial spot disease on almond
Full text linkWe report the annotated genome sequence of Xanthomonas arboricola pv. pruni strain Xap33, isolated from almond leaves showing bacterial spot disease symptoms in Spain. The availability of this genome sequence will aid our understanding of the infection mechanism of this bacterium as well as its relationship to other species of the same genus.Publishe
<i>Xanthomonas arboricola</i>pv.<i>pruni</i>, causal agent of bacterial spot of stone fruits and almond: its genomic and phenotypic characteristics in the<i>X. arboricola</i>species context
No full textBackground: Xanthomonas arboricola pv. pruni (Xap) causes bacterial spot of stone fruits and almond, an important disease that may reduce the yield and vigour of the trees, as well as the marketability of affected fruits. Xap lies within the Xanthomonas genus, which has been intensively studied because of its strain specialization and host range complexity. Here, we summarize the recent advances in our understanding of the complexities of Xap, including studies of the molecular features that result after comparative phenotypic and genomic analyses, in order to obtain a clearer overview of the bacterial behaviour and infection mechanism in the context of the X. arboricola species.
Taxonomic status: Bacteria; Phylum Proteobacteria; Class Gammaproteobacteria; Order Xanthomonadales; Family Xanthomonadaceae; Genus Xanthomonas; Species X. arboricola; Pathovar pruni.
Host range and symptoms: Xap infects most Prunus species, including apricot, peach, nectarine, plum and almond, and occasionally cherry. Symptoms are found on leaves, fruits, twigs and branches or trunks. In severe infections, defoliation and fruit dropping may occur.
Distribution: Bacterial spot of stone fruits and almond is worldwide in distribution, with Xap being isolated in Africa, North and South America, Asia, Europe and Oceania. It is a common disease in geographical areas in which stone fruits and almonds are grown. Xap is listed as a quarantine organism in several areas of the world.
Genome: The genomes of six isolates from Xap have been publicly released. The genome consists of a single chromosome of around 5 000 000 bp with 65 mol% GC content and an extrachromosomal plasmid element of around 41 000 bp with 62 mol% GC content. Genomic comparative studies in X. arboricola have allowed the identification of putative virulence components associated with the infection process of bacterial spot of stone fruits and almond.
Disease control: Management of bacterial spot of stone fruits and almond is based on an integrated approach that comprises essential measures to avoid Xap introduction in a production zone, as well as the use of tolerant or resistant plant material and chemical treatments, mainly based on copper compounds. Management programmes also include the use of appropriate cultivation practices when the disease is already established. Finally, for the effective control of the disease, appropriate detection and characterization methods are needed for use in symptomatic or asymptomatic samples as a first approach for pathogen exclusion. USEFUL WEBSITES: https://gd.eppo.int/taxon/XANTPR; http://www.cost.eu/COST_Actions/ca/CA16107; http://www.xanthomonas.org
Comparative Genomic and Phenotypic Characterization of Pathogenic and Non-Pathogenic Strains of Xanthomonas arboricola Reveals Insights into the Infection Process of Bacterial Spot Disease of Stone Fruits
Full text linkXanthomonas arboricola pv. pruni is the causal agent of bacterial spot disease of stone fruits, a quarantinable pathogen in several areas worldwide, including the European Union. In order to develop efficient control methods for this disease, it is necessary to improve the understanding of the key determinants associated with host restriction, colonization and the development of pathogenesis. After an initial characterization, by multilocus sequence analysis, of 15 strains of X. arboricola isolated from Prunus, one strain did not group into the pathovar pruni or into other pathovars of this species and therefore it was identified and defined as a X. arboricola pv. pruni look-a-like. This non-pathogenic strain and two typical strains of X. arboricola pv. pruni were selected for a whole genome and phenotype comparative analysis in features associated with the pathogenesis process in Xanthomonas. Comparative analysis among these bacterial strains isolated from Prunus spp. and the inclusion of 15 publicly available genome sequences from other pathogenic and non-pathogenic strains of X. arboricola revealed variations in the phenotype associated with variations in the profiles of TonB-dependent transporters, sensors of the two-component regulatory system, methyl accepting chemotaxis proteins, components of the flagella and the type IV pilus, as well as in the repertoire of cell-wall degrading enzymes and the components of the type III secretion system and related effectors. These variations provide a global overview of those mechanisms that could be associated with the development of bacterial spot disease. Additionally, it pointed out some features that might influence the host specificity and the variable virulence observed in X. arboricola.Publishe
Development of an efficient real-time quantitative PCR protocol for detection of Xanthomonas arboricola pv. pruni in Prunus species
Full text linkThis small meeting was a joint meeting with the FP7 KBBE phytosanitary monitoring project Q-DETECT and was held at the Dutch Phytosanitary labs in Wageningen NL. Updates on COST873 partner progress with Xanthomonas arboricola pv. pruni diagnostics, detection and genomics were presented by representatives from Spain, The Netherlands and Switzerland. Plans were developed for collaborative research to improve diagnostic methods and validate detection/monitoring implementation with local phytosanitary inspector end-user
Pan-Genomic Analysis Permits Differentiation of Virulent and Non-virulent Strains of Xanthomonas arboricola That Cohabit Prunus spp. and Elucidate Bacterial Virulence Factors
Full text linkXanthomonas 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
A reliable qPCR technique for detecting viable Xanthomonas arboricola pv. pruni cells
Full text linkXanthomonas arboricola pv. pruni (Xap) is the causal agent of bacterial spot of stone fruits and almond (Prunus spp). Detection of Xap is typically carried out using quantitative real-time PCR (qPCR) combined with culture-based isolation. However, qPCR does not differentiate between viable and dead cells, potentially leading to an overestimation of the infective population in a sample. Such overestimation could result in unnecessary phytosanitary measures. The present study aims to develop a specific protocol ideally targeting to detection of only live Xap bacterial cells. To address this challenge, the viable quantitative PCR (v-qPCR) method was evaluated using three nucleic acid-binding dyes: propidium monoazide (PMA), a combination of PMA and ethidium monoazide (EMA), and PMAxx™, an improved version of PMA. PMAxx™ proved to be the most suitable dye for the detection and quantification of living bacterial cells. This methodology was also evaluated in infected plant material over time and can be considered a rapid and reliable alternative to PCR methods for detecting only those putative infective Xap that may pose a risk for Prunus crops.Este trabajo fue financiado por el proyecto PID2021-123600ORC44, con el apoyo de MICIU/AEI/https://doi.org/10.13039/501100011033 y por el FEDER, UECut-off CtLODXanthomonas arboricola pv. pruniV-qPCRIntercalating dyeViable cell detectionPublishe
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