Ana Palacio-Bielsa

• Contract at Agrifood Research and Technology Centre of Aragon

Xanthomonas 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...

Detecting plant pathogens and diagnosing diseases are critical components of successful pest management. These key areas have undergone significant advancements driven by breakthroughs in molecular biology and remote sensing technologies within the realm of precision agriculture. Notably, nucleic acid amplification techniques, with recent emphasis...

The genus Euphorbia is widespread and possesses medicinal uses. However, there is no available phytochemical information on Euphorbia serrata L. This study investigates the composition of the hydromethanolic extract of its aerial parts and proposes its utilization for crop protection purposes, following integrated pest management guidelines. Gas ch...

The Euphorbia genus is the third-largest group of blooming plants, features a rich morphological variability, has a near-cosmopolitan distribution, and diverse medicinal uses. Nonetheless, phytochemical information about Euphorbia serrata L. extracts is not available. The objective of this research was to examine the constituents of the hydromethan...

Phytopathogenic bacteria represent a risk to global food production by impacting a variety of crops. The aim of this study was to characterize the contents of bioactive constituents in extracts from Ginkgo biloba L. leaves and fruits and test their activity against six phytopathogenic bacteria that affect horticultural crops. Gas chromatography–mas...

Pathogenic microorganisms, including fungi, oomycetes, bacteria, viruses, and viroids, constitute a serious threat to agriculture worldwide [...]

The yew tree (Taxus baccata L.) is considered in folklore a symbol of immortality due to its qualities of longevity and regeneration. Despite its poisonous reputation, the yew tree has a long history of medicinal use, particularly in the form of extracts from its leaves and bark. In the work presented herein, gas chromatography-mass spectrometry (G...

Xanthomonas arboricola comprises a number of economically important fruit tree pathogens classified within different pathovars. Dozens of non-pathogenic and taxonomically un-validated strains are also designated as X. arboricola leading to a complicated taxonomic status in the species. In this study, we have evaluated the whole genome resources of...

https://www.bubok.es/libros/257130/ENFERMEDADES-DE-PLANTAS-CAUSADAS-POR-BACTERIAS

Este tratado sobre las bacterias fitopatógenas y las enfermedades que ocasionan, ofrece una revisión científica actualizada, pero también realista y práctica. Consta de seis capítulos generales introductorios, 13 sobre géneros bacterianos y 29 sobre las enfermedades de mayor importancia actual para la agricultura española y también de las que repre...

El chancro espumoso (“foamy canker” en inglés) es una enfermedad de etiología desconocida detectada en almendros.

Xanthomonas arboricola pv. pruni (Xap) causes bacterial spot of stone fruits. The bacteria produce lesions that reduce the marketability of fruit and the yield and vigor of the trees. Xap is within the interesting Xanthomonas genus, which has been intensively studied due its strain specialization and its host range complexity. Comparative genomics...

Background: Xanthomonas arboricola pv. pruni (Xap) causes bacterial spot of stone fruits and almond, an important disease that may reduce the yield and vigor of the trees, as well as the marketability of affected fruits. Xap, is within the Xanthomonas genus which has been intensively studied due its strain specialization and the host range complexi...

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 characteris...

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 char...

Phylogenetic analysis of 17 strains of Xanthomonas arboricola based on the core genome sequence (2,714 potential groups of orthologous genes) and representation of the distribution of the potential orthologous cluster genes of the pangenome (7,074) within the analyzed genome sequences. Sequences were aligned using PRANK and maximum likelihood analy...

Maximum likelihood trees based on partial sequences of dnaK, fyuA, gyrB, and rpoD. Bootstrap values (1,000 replicates) are indicated over or below the branches.

Schematic representation of bacterial-caused symptoms on Prunus persica (GF-305), Hordeum vulgare, Nicotiana benthamiana, Nicotiana tabacum, and Solanum lycopersicum 21 dpi. Leaves were infiltrated with 108 CFU/mL of bacteria or with sterile phosphate saline buffer (PBS) as negative control.

Presence of the plasmid pXap41 in the genome-sequenced strains of Xanthomonas arboricola. Comparative sequence analysis was performed using Blastn with an expected value threshold of 0.001 and graphically represented by the BRIG tool. Each concentric circle represents one of the analyzed genomes.

Bacterial strains used in this study.

Unique clusters of orthologous genes encoded in the genome sequence of the non-virulent to Prunus strains of Xanthomonas arboricola CITA 14 and CITA 124 as well as those encoded in the pathogenic strains of the pathovars corylina, juglandis and pruni.

Orthologous protein coding sequences (CDS) of 17 strains of Xanthomonas arboricola associated with pathogenesis.

Comparative statistics among strains of Xanthomonas arboricola based in the distribution of the potential orthologous clusters of gene contained in the genome sequence of 17 bacterial strains. Histogram representing the Jaccard distance distribution among the analyzed genomes (A). Principal component analysis based in the potential orthoglogous clu...

In silico representation of the presence of xopE3 and ftsX and the hybridization zone for the primers and probes used for real-time PCRs amplification in Xanthomonas arboricola. Comparative sequence analysis was performed using Blastn with an expected value threshold of 0.001 and graphically represented by the BRIG tool. Each concentric circle repr...

In silico representation of the hybridization zone for the primers used in two PCR amplification protocols published to identify Xanthomonas arboricola pv. pruni. Comparative sequence analysis was performed using Blastn with an expected threshold value of 0.001. The circular graphic has been constructed using BRIG. Each concentric circle represents...

Genome statistics of 17 strains of Xanthomonas arboricola with a variable virulence.

This book, containing 20 chapters, deals with almond taxonomy, morphology, physiology, cultivation history, production, breeding (classical and molecular), cultivar development, genomics, pollen-style (in)compatibility, rootstock development, propagation, orchard management, environmental and water requirements, nutrition, diseases, pests, harvesti...

X. arboricola pv. pruni strains from international collections. (PDF)

Nucleotide sequence in Xanthomonas arboricola pv. pruni strain CFBP 3894 of TR loci that were excluded from the analysis or for which new primer combinations were designed. (PDF)

Xanthomonas arboricola pv. pruni strains isolated from 11 provinces in Spain. (PDF)

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. Citation Garita-Cambronero J, Palacio-Bielsa A...

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...

Xanthomonas 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, colo...

Genome statistics of 18 X. arboricola strains according to the automatic annotation performed using Prokka. (XLSX)

Unique protein coding sequences (CDS) and related features found in the draft genome sequence of X. arboricola strain CITA 44 and X. arboricola pv. pruni strains CITA 33 and IVIA 26262.1. (XLSX)

Transmission electron microscopy of X. arboriola strain CITA 44. Negative staining showed monoflagellated cell from the edge of the dendritic swarming colony 24 hpi in 0.5% PYM agar plates. (TIF)

Annotated protein sequences shared by 18 pathogenic and non-pathogenic strains of X. arboricola. (XLSX)

Amino acid alignment of two variants of the FliC found in X. arboricola. Sequence alignment, performed using ClustalW, showed the amino acid change in the position number 43 of the amino terminal region of FliC. (TIF)

Nucleotide alignment of type III effector xopAQ and the PIP-box found in X. arboricola pv. pruni. Sequence alignment, performed using ClustalW, showed a slight variation among X. arboricola and other Xanthomonas (A) as well as a variant in PIP-box sequence (B). (TIF)

Orthologous protein coding sequences (CDS) of nine strains of X. arboricola associated with pathogenesis. (XLSX)

Nucleotide genome sequence comparison of X. arboricola pv. pruni strains CITA 33 and IVIA 2626.1 and the non-pathogenic strain CITA 44. Genome sequences were compared against each other based on Blastn results and represented as a circular map using the CGview tool. From outside to center: strain CITA 33, strain IVIA 2626.1, strain CITA 44, GC cont...

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...

Operational capacity of real-time PCR and loop-mediated isothermal amplification (LAMP) diagnostic assays for detection of Xanthomonas arboricola pv. pruni were established in a ring-test involving four laboratories. Symptomatic and healthy almond leaf samples with two methods of sample preparation were analyzed. Kappa coefficient, sensitivity, spe...

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.

Erwinia amylovora was detected on pome fruits in the Aragón region (North-Eastern Spain), in a ca. 5 km radius area located in the mid Jalón river (mid Ebro Valley) in the province of Zaragoza, during 2000-2003. Eight years have now passed since this pathogen was last detected, without new infections being reported in the same area. The bases for s...

In 2002, typical symptoms of bacterial spot disease of stone fruits caused by Xanthomomas arboricola pv. pruni (Xap) were observed for the first time on Japanese plum in Badajoz (south-western Spain). During the following years, the pathogen was found in seven other eastern and northern Spanish provinces (Valencia, Alicante, Zaragoza, Huesca, Navar...

Xanthomonas arboricola pv. pruni (Xap), the causal agent of bacterial spot disease of stone fruits and almond , has a quarantine status for the European Union and the European and Mediterranean Plant Protection Organization. The symptoms in the diverse hosts show some differences and, although being quite typical, could be confused with those of so...

Xanthomonas arboricola pv. pruni (Xap), the causal agent of bacterial spot disease of stone fruits and almond , is regulated as a quarantine pathogen in the Eu-ropean Union and the European and Mediterranean Plant Protection Organization (EPPO). Xap can have an epiphytic phase and/or be latent and, consequently, it can be transmitted by different t...

The number of described pathogenic and non-pathogenic Erwinia species associated with pome fruit trees, especially pear trees, has increased in recent years, but updated comparative information about their similarities and differences is scarce. The causal agent of the fire blight disease of rosaceous plants, Erwinia amylovora, is the most studied...

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 vi...

Diagnosis and detection are key aspects related to plant health status. A critical review of the available di-agnostic methods utilised for Agrobacterium rhizogenes and A. tumefaciens, Pseudomonas amygdali, P. syringae pv. mors-prunorum, P. syringae pv. persicae, P. syringae pv. syringae and Xanthomonas arboricola pv. pruni, the main pathogens of t...

Six Dickeya spp. strains representative of a larger group of bacteria isolated from potato, onion and irrigation water in Spain between years 2003–2005, were characterised by biochemical, serological, molecular and pathogenicity assays. Biochemical and serological differences, as well as pathogenic behaviour in host range and virulence levels, were...

Symptoms characteristic of bacterial spot disease of Prunus spp. (4) were observed on almond trees (Prunus dulcis (Mill.) Webb) in 14 localities of Comunidad Valenciana (eastern Spain) and Aragon (northeastern Spain) between 2006 and 2009. Symptoms were first noted in the spring and were observed until leaf fall. Initial infections began on leaves...

Fifty-six tumorigenic Spanish grapevine strains of Agrobacterium spp. were tested for biovar classification, pathogenicity on several hosts, opine utilization, 16S rRNA gene sequencing and PCR amplifications using five primer sets targeting chromosomal and Ti plasmid genes. Fifty of them belonged to A. vitis (biovar 3), three to A. tumefaciens (bio...

PCR-based methods offer advantages over more traditional diagnostic tests, in that organisms do not need to be cultured prior to their detection and protocols are highly sensitive and rapid. Consequently, there is a shift in research towards DNA-based techniques. Although reports already exist on a variety of PCR-based fingerprinting assays used to...

Thirteen Spanish potato isolates of Dickeya chrysanthemi obtained from different cultivars, regions and years have been characterised by biochemical, physiological, serological, molecular and pathogenicity tests. Isolates studied have been classified into biovars 1, 3, 5 and 6 by a microtitre system that correlates with the conventional tests in tu...

The population structure and diversity within a Citrus exocortis viroid (CEVd) isolate was estimated by single strand conformation polymorphism (SSCP) and sequence analysis. A predominant sequence variant (V1) representing 52.8% of the overall population was identified. V1 and other additional variants presented a composition of the P domain charac...

Borage (Borago officinalis L.) is an important vegetable crop for consumption in the Ebro Valley of northeastern Spain. During the autumn and spring of the last 10 years, black necrotic lesions were observed in leaf petioles of white-flowered borage plants in greenhouses and seedbeds in Zaragoza, Spain. These lesions developed from the soil line an...

Seven citrus isolates of Hop stunt viroid (HSVd) were subjected to retrotranscription and DNA amplification (RT-PCR), cloning and sequencing. Single stranded polymorphism (SSCP) analysis demonstrated the existence of variability among and within cachexia inducing sources of HSVd. The electrophoretic profiles of SSCP appeared to be able to discrimin...

An imprint hybridization method has been designed to detect viroids from infected tissues. Freshly cut tissue pieces from inoculated citrons can be imprinted by firmly pressing the cut surface onto positively charged Nylon membranes. Imprints, once fixed on the membrane, can be processed immediately or stored. Processing of the imprinted membranes...

Single-strand conformation polymorphism (SSCP) has been adopted as a tool for viroid characterization. Nucleic acid extracts from a viroid field isolate containing CEVd was subjected to retrotranscription and PCR amplification using a set of contiguous CEVd-specific primers. The analysis of cloned DNAs recovered from this isolate illustrates the ex...

The Group II of citrus viroids (CVd-II) can be considered generically as a group of viroid variants related to the hop stunt viroid (HSVd) by molecular structure and sequence. Five field cachexia isolates and a non-cachexia source were subjected to retrotranscription and DNA amplification, cloning and sequencing. SSCP analysis demonstrated the exis...

A method based on the hybridisation of tissue imprints was developed for routine indexing of citrus viroids. For maximum sensitivity and reliability, the inoculation of Citrus medica (Etrog citron) as a viroid amplification host is required. Hybridisation against Digoxigenin-labelled RNA- or DNA-probes followed by detection of viroid-probe hybrids...

The potential of routine single-strand conformation polymorphism (SSCP) analysis for viroid characterization has been evaluated. Electrophoresis of 311 cloned full length viroid DNA inserts recovered from a field isolate of citrus exocortis viroid (CEVd) showed shifts in the migration of the cDNA or/and hDNA strands in non-denaturing 14% polyacryla...