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Published Volume: PHYTOPATHOLOGY, vol. 108, no. 10, pp. S1.103

Four subspecies of Lonsdalea quercina ( L. quercina subsp. quercina , L. quercina subsp. britannica , L. quercina subsp. iberica and L. quercina subsp. populi ) were studied by genome sequence-derived average nucleotide identity (ANI), phylogenetic analysis based on 16S rRNA gene sequences, multilocus sequence analysis (MLSA) and phenotypic characteristics. In phylogenetic trees, based on 16S rRNA gene sequences, and in MLSA data, the four subspecies were divided into four subclusters in the Lonsdalea clade with high boot strap support. The ANI values between the four subspecies were 88.71–93.38 %, respectively, lower than the proposed species boundary ANI cut-off (95–96 %) that is considered the most important criterion to reclassify these subspecies at the species level. It is proposed that three subspecies be elevated to the species level as Lonsdalea britannica sp. nov. (type strain R-43280T=LMG 26267T=NCPPB 4481T=CFCC 10822T), Lonsdalea iberica sp. nov. (type strain R-44166T=LMG 26264T=NCPPB 4490T=CFCC 10824T) and Lonsdalea populi sp. nov. (type strain NY060T=DSM 25466T=NCAIM B 02483T=LMG 27349T=CFCC 13125T).

La bacteria Lonsdalea quercina (ex Brenneria quercina) ssp. populi ha sido recientemente descrita en Hungría y China como una nueva subespecie causante del chancro de la corteza del chopo. Los árboles afectados presentan chancros longitudinales en el tronco, de los que fluyen inicialmente exudados acuosos oscuros, seguidos de abundantes exudados espumosos de color blanco. Bajo la corteza se observa una masa cremosa de color blanquecino. Se produce un debilitamiento de los árboles y aquellos más severamente afectados pueden llegar a morir. En este trabajo se presenta la primera detección de L. quercina ssp. populien España y se describen los métodos de diagnóstico utilizados.

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. © 2017 Garita-Cambronero, Palacio-Bielsa, López and Cubero.

Lonsdalea quercina (ex Brenneria quercina) subsp. populi es una bacteria recientemente identificada en Hungría y China como una nueva subespecie causante del chancro de la corteza del chopo. Los árboles afectados presentan chancros longitudinales en el tronco, de los que fluyen abundantes exudados espumosos de color blanco y exudados acuosos oscuros que tiñen la corteza. Los chopos afectados muestran un debilitamiento generalizado. En España se han localizado choperas con síntomas similares y se ha identificado L. quercina subsp. populi como el agente causal de los mismos. En este trabajo se presenta la primera detección de esta bacteria en España y se describen los métodos de diagnóstico e identificación utilizados. Esta nueva bacteriosis podría tener un impacto económico importante, siendo necesario evaluar las pérdidas causadas y realizar nuevas prospecciones para determinar su distribución en el país.

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. © 2017 Garita-Cambronero, Palacio-Bielsa, López and Cubero.

Published

Xanthomonas arboricola pv. pruni is the causal agent of the bacterial spot disease of stone fruits, almond and some ornamental Prunus species. In Spain it was first detected in 2002 and since then, several outbreaks have occurred in different regions affecting mainly Japanese plum, peach and almond, both in commercial orchards and nurseries. As the origin of the introduction(s) was unknown, we have assessed the genetic diversity of 239 X. arboricola pv. pruni strains collected from 11 Spanish provinces from 2002 to 2013 and 25 reference strains from international collections. We have developed an optimized multilocus variable number of tandem repeat analysis (MLVA) scheme targeting 18 microsatellites and five minisatellites. A high discriminatory power was achieved since almost 50% of the Spanish strains were distinguishable, confirming the usefulness of this genotyping technique at small spatio-temporal scales. Spanish strains grouped in 18 genetic clusters (conservatively delineated so that each cluster contained haplotype networks linked by up to quadruple-locus variations). Furthermore, pairwise comparisons among populations from different provinces showed a strong genetic differentiation. Our results suggest multiple introductions of this pathogen in Spain and redistribution through contaminated nursery propagative plant material. This work was supported by Instituto Nacional de Tecnología Agraria y Alimentaria. Project RTA-2011-00140-C03-01 (http://www.inia. es) to PLS MCM JP MML, Euphresco project (266505-FP7-ERANET Euphresco II) to PLS MCM JP APB MML, European Social Fund to PLS KB MCM JP APB CV MML OP, European Regional Published

Xanthomonas arboricola pv. pruni, the causal agent of bacterial spot disease of stone fruit, is considered a quarantine organism by the European Union and the European and Mediterranean Plant Protection Organization (EPPO). The bacterium can undergo an epiphytic phase and/or be latent and can be transmitted by plant material, but currently, only visual inspections are used to certify plants as being X. arboricola pv. pruni free. A novel and highly sensitive real-time TaqMan PCR detection protocol was designed based on a sequence of a gene for a putative protein related to an ABC transporter ATP-binding system in X. arboricola pv. pruni. Pathogen detection can be completed within a few hours with a sensitivity of 10 2 CFU ml −1 , thus surpassing the sensitivity of the existing conventional PCR. Specificity was assessed for X. arboricola pv. pruni strains from different origins as well as for closely related Xanthomonas species, non- Xanthomonas species, saprophytic bacteria, and healthy Prunus samples. The efficiency of the developed protocol was evaluated with field samples of 14 Prunus species and rootstocks. For symptomatic leaf samples, the protocol was very efficient even when washed tissues of the leaves were directly amplified without any previous DNA extraction. For samples of 117 asymptomatic leaves and 285 buds, the protocol was more efficient after a simple DNA extraction, and X. arboricola pv. pruni was detected in 9.4% and 9.1% of the 402 samples analyzed, respectively, demonstrating its frequent epiphytic or endophytic phase. This newly developed real-time PCR protocol can be used as a quantitative assay, offers a reliable and sensitive test for X. arboricola pv. pruni, and is suitable as a screening test for symptomatic as well as asymptomatic plant material.

espanolEl azafran cultivado en Espana esta adquiriendo relevancia en las ultimas decadas como producto de gran calidad, lo que requiere la seleccion de cormos (sus organos reproductivos) sanos para la plantacion con el objetivo de mantener un adecuado estado fitosanitario del cultivo. Este trabajo presenta un estudio del estado fitosanitario del azafran en Teruel, donde el cultivo fue muy importante economica y socialmente. Ademas, este estudio pretende ser de utilidad para las zonas productoras con caracteristicas agroclimaticas similares. Con dichos objetivos, se prospectaron 10 plantaciones comerciales de azafran en 6 localidades del valle del Jiloca entre los anos 2008 y 2011, estudiando la presencia de insectos, acaros, nematodos, virus, bacterias y malas hierbas. El acaro Rhizoglyphus robini, una de las plagas mas importantes del azafran, se detecto en los cormos y en el suelo en una parcela. Tambien el nematodo Aphelenchoides blastophtorus, plaga en plantas ornamentales, se encontro abundantemente en cormos de dos parcelas. Se detectaron infecciones ocasionales de virus del genero Potyvirus en el cultivo y en la mala hierba Eruca vesicaria. Las malas hierbas Lolium rigidum y Descurainia sophia podrian causar serios problemas de competencia al cultivo y se considera necesario realizar operaciones de escarda en otono y en invierno. No se detectaron insectos nocivos ni bacterias fitopatogenas. La multiplicacion vegetativa del azafran hace aconsejable realizar muestreos, especialmente en los cormos antes de ser replantados, para detectar la presencia de acaros, nematodos y virus que podrian ocasionar perdidas de produccion y calidad EnglishIn the last decades, saffron produced in Spain is gaining relevance as a high-quality product, which requires the selection of healthy corms (the reproductive organ) for planting in order to maintain adequa - te phytosanitary status of the crop. In this work, the phytosanitary status of saffron was studied in Teruel (Aragon, Spain), where the crop has economic and social importance. Moreover, it aims to be useful for the production areas with similar agro-climatic characteristics. Ten commercial saffron plantations in six locations of the Jiloca valley have been surveyed between 2008 and 2011 and the presence of insects, mites, nematodes, virus, bacteria and weeds was studied. The mite Rhizoglyphus robini, one of the most important pests of saffron, was detected in both corms and soil in one plantation. The nematode Aphelenchoides blastophtorus, pest in ornamental plants, was also found in corms in two plantations. Potyvirus infections were occasionally detected in both the crop and in the weed Eruca vesicaria. The weeds Lolium rigidum and Descurainia sophia could cause diminutions of the yield by competition, therefore, weeding operations are necessary in autumn and winter. No harmful insects and phytopatogenic bacteria were detected. Because reproduction is only possible through corm propagation, it is advisable to analyse the plants, especially the corms, before being re-planted, in order to detect the presence of mites, nematodes and virus that could reduce yield and quality decreases

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The 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.

Published

Xanthomonas arboricola is a species in genus Xanthomonas which is mainly comprised of plant pathogens. Among the members of this taxon, X. arboricola pv. pruni, the causal agent of bacterial spot disease of stone fruits and almond, is distributed worldwide although it is considered a quarantine pathogen in the European Union. Herein, we report the draft genome sequence, the classification, the annotation and the sequence analyses of a virulent strain, IVIA 2626.1, and an avirulent strain, CITA 44, of X. arboricola associated with Prunus spp. The draft genome sequence of IVIA 2626.1 consists of 5,027,671 bp, 4,720 protein coding genes and 50 RNA encoding genes. The draft genome sequence of strain CITA 44 consists of 4,760,482 bp, 4,250 protein coding genes and 56 RNA coding genes. Initial comparative analyses reveals differences in the presence of structural and regulatory components of the type IV pilus, the type III secretion system, the type III effectors as well as variations in the number of the type IV secretion systems. The genome sequence data for these strains will facilitate the development of molecular diagnostics protocols that differentiate virulent and avirulent strains. In addition, comparative genome analysis will provide insights into the plant-pathogen interaction during the bacterial spot disease process. © 2016 Garita-Cambronero et al.

Xanthomonas arboricola is a species in genus Xanthomonas which is mainly comprised of plant pathogens. Among the members of this taxon, X. arboricola pv. pruni, the causal agent of bacterial spot disease of stone fruits and almond, is distributed worldwide although it is considered a quarantine pathogen in the European Union. Herein, we report the draft genome sequence, the classification, the annotation and the sequence analyses of a virulent strain, IVIA 2626.1, and an avirulent strain, CITA 44, of X. arboricola associated with Prunus spp. The draft genome sequence of IVIA 2626.1 consists of 5,027,671Â bp, 4,720 protein coding genes and 50 RNA encoding genes. The draft genome sequence of strain CITA 44 consists of 4,760,482Â bp, 4,250 protein coding genes and 56 RNA coding genes. Initial comparative analyses reveals differences in the presence of structural and regulatory components of the type IV pilus, the type III secretion system, the type III effectors as well as variations in the number of the type IV secretion systems. The genome sequence data for these strains will facilitate the development of molecular diagnostics protocols that differentiate virulent and avirulent strains. In addition, comparative genome analysis will provide insights into the plant-pathogen interaction during the bacterial spot disease process.

Xanthomonas arboricola is a species in genus Xanthomonas which is mainly comprised of plant pathogens. Among the members of this taxon, X. arboricola pv. pruni, the causal agent of bacterial spot disease of stone fruits and almond, is distributed worldwide although it is considered a quarantine pathogen in the European Union. Herein, we report the draft genome sequence, the classification, the annotation and the sequence analyses of a virulent strain, IVIA 2626.1, and an avirulent strain, CITA 44, of X. arboricola associated with Prunus spp. The draft genome sequence of IVIA 2626.1 consists of 5,027,671 bp, 4,720 protein coding genes and 50 RNA encoding genes. The draft genome sequence of strain CITA 44 consists of 4,760,482 bp, 4,250 protein coding genes and 56 RNA coding genes. Initial comparative analyses reveals differences in the presence of structural and regulatory components of the type IV pilus, the type III secretion system, the type III effectors as well as variations in the number of the type IV secretion systems. The genome sequence data for these strains will facilitate the development of molecular diagnostics protocols that differentiate virulent and avirulent strains. In addition, comparative genome analysis will provide insights into the plant-pathogen interaction during the bacterial spot disease process. © 2016 Garita-Cambronero et al.

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La Red FRUTSAN 112RT0441, perteneciente al Programa Iberoamericano de Ciencia y Tecnología para el Desarrollo (CYTED), se inició en 2011 y en él participan investigadores de España, Argentina, Bolivia, Brasil, Chile y Uruguay. El objetivo de FRUT-SAN es profundizar en el conocimiento científico-tecnológico de las principales enfermedades y plagas que afectan el cultivo de los frutales de hueso para optimizar conjuntamente las estrategias de control integrado. En este trabajo se revisan comparativamente la situación y conocimientos sobre la mancha bacteriana de los frutales de hueso y del almendro (Xanthomonas arboricola pv. pruni) en España y Sudamérica.

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El 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.

La mancha bacteriana de los frutales de hueso y del almendro es una enfermedad emergente en España. Está causada por Xanthomonas arboricola pv. pruni, patógeno considerado de cuarentena en la Unión Europea y por la European and Mediterranean Plant Protection Organization. La bacteria se identificó en nuestro país en el año 2002 y, desde entonces, se han detectado nuevos brotes en distintas Comunidades Autónomas. En este trabajo se describen aspectos sobre la sintomatología, epidemiología y medidas de control de esta bacteriosis

La situación del fuego bacteriano ha evolucionado en España en los últimos años y el escenario al que nos enfrentamos actualmente es muy distinto al de años anteriores. En 2010 nos encontrábamos con brotes erradicados en algunas zonas españolas y otros en proceso de erradicación, y en la Comunitat Valenciana no se había detectado la enfermedad. Sin embargo, en 2014 muchas Comunidades Autónomas han perdido ya el estatus de zona protegida en la Unión Europea para Erwinia amylovora en todo su territorio, y la Comunitat Valenciana ha declarado como zonas no protegidas dos municipios de la provincia de Valencia y dos comarcas de la provincia de Alicante. En esta última provincia se localiza la mayor zona productora de Europa de níspero japonés (Eriobotrya japonica), que es un frutal sensible a E. amylovora. Para que la enfermedad no afecte a este cultivo, que supone la mayor fuente económica de esta zona, es necesario extremar las medidas de prevención.

CYTED. Programa Iberoamericano de Ciencia y Tecnología para el Desarrollo

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Published Trabajo financiado por INIA, proyecto RTA2011-00140-C03-03

CYTED. Programa Iberoamericano de Ciencia y Tecnología para el Desarrollo

Published Trabajo financiado por el Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria, proyecto RTA2011-00140-d03-01

Published Trabajo financiado por el Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria, proyecto RTA2011-00140-d03-03

Published Trabajo financiado por el Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria, proyecto RTA2011-00140-d0T-02

Published Trabajo financiado por el Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), proyecto RTA2011-00140-C03-02 y por la Red CYTED FRUT-SAN 112RT0441

We 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.

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