Xanthomonadaceae plant diseases
2.7K views | +1 today
Follow
Your new post is loading...
Your new post is loading...
Scooped by COST Action CA16107
Scoop.it!

Pr‐favoured variants of the bacteriophytochrome from the plant pathogen Xanthomonas campestris hint on light regulation of virulence‐associated mechanisms - Conforte - - The FEBS Journal - Wiley On...

Pr‐favoured variants of the bacteriophytochrome from the plant pathogen Xanthomonas campestris hint on light regulation of virulence‐associated mechanisms - Conforte - - The FEBS Journal - Wiley On... | Xanthomonadaceae plant diseases | Scoop.it
The bacteriophytochrome photoreceptor XccBphP is involved in the light‐mediated virulence responses from the plant pathogen Xanthomonas campestris. Here, variants with single amino acid change
No comment yet.
Scooped by COST Action CA16107
Scoop.it!

HPLC-MS/MS method applied to an untargeted metabolomics approach for the diagnosis of “olive quick decline syndrome” | SpringerLink

HPLC-MS/MS method applied to an untargeted metabolomics approach for the diagnosis of “olive quick decline syndrome” | SpringerLink | Xanthomonadaceae plant diseases | Scoop.it
Olive quick decline syndrome (OQDS) is a disorder associated with bacterial infections caused by Xylella fastidiosa subsp. pauca ST53 in olive trees. Metabolic profile changes occurring in infected olive trees are still poorly investigated, but have the potential to unravel reliable biomarkers to be exploited for early diagnosis of infections. In this study, an untargeted metabolomic method using high-performance liquid chromatography coupled to quadrupole-time-of-flight high-resolution mass spectrometry (HPLC-ESI-Q-TOF-MS) was used to detect differences in samples (leaves) from healthy (Ctrl) and infected (Xf) olive trees. Both unsupervised and supervised data analysis clearly differentiated the groups. Different metabolites have been identified as potential specific biomarkers, and their characterization strongly suggests that metabolism of flavonoids and long-chain fatty acids is perturbed in Xf samples. In particular, a decrease in the defence capabilities of the host after Xf infection is proposed because of a significant dysregulation of some metabolites belonging to flavonoid family. Moreover, oleic acid is confirmed as a putative diffusible signal factor (DSF). This study provides new insights into the host-pathogen interactions and confirms LC-HRMS-based metabolomics as a powerful approach for disease-associated biomarkers discovery in plants. Graphical abstract
No comment yet.
Scooped by COST Action CA16107
Scoop.it!

Barrier effects on the spatial distribution of Xylella fastidiosa in Alicante, Spain | bioRxiv

bioRxiv - the preprint server for biology, operated by Cold Spring Harbor Laboratory, a research and educational institution
No comment yet.
Scooped by COST Action CA16107
Scoop.it!

Anatomical and biochemical studies of Spartium junceum infected by Xylella fastidiosa subsp. multiplex ST 87 | SpringerLink

Anatomical and biochemical studies of Spartium junceum infected by Xylella fastidiosa subsp. multiplex ST 87 | SpringerLink | Xanthomonadaceae plant diseases | Scoop.it
Spartium junceum L. is a typical species of Mediterranean shrubland areas, also grown in gardens and parks as an ornamental. In recent years in Europe, S. junceum has been recurrently found to be infected by different subspecies and genotypes of the quarantine regulated bacterium Xylella fastidiosa (Xf). This work presents for the first time the anatomy of S. junceum plants that we found, by means of genetic and immunochemistry analysis, to be naturally infected by Xf subsp. multiplex ST87 (XfmST87) in Monte Argentario (Grosseto, Tuscany, Italy), a new outbreak area within the EU. Our anatomical observations showed that bacteria colonized exclusively the xylem conductive elements and moved horizontally to adjacent vessels through pits. Interestingly, a pink/violet matrix was observed with Toluidine blue staining in infected conduits indicating a high content of acidic polysaccharides. In particular, when this pink-staining matrix was observed, bacterial cells were either absent or degenerated, suggesting that the matrix was produced by the host plant as a defense response against bacterial spread. In addition, a blue-staining phenolic material was found in the vessels and, at high concentration, in the pits and inter-vessels. SEM micrographs confirmed that polysaccharide and phenolic components showed different structures, which appear to be related to two different morphologies: fibrillary and granular, respectively. Moreover, our LM observations revealed bacterial infection in xylem conductive elements of green shoots and leaves only, and not in those of other plant organs such as roots and flowers.
No comment yet.
Scooped by COST Action CA16107
Scoop.it!

Microorganisms | Free Full-Text | Antibiofilm Activity of a Trichoderma Metabolite against Xanthomonas campestris pv. campestris, Alone and in Association with a Phage

Microorganisms | Free Full-Text | Antibiofilm Activity of a Trichoderma Metabolite against Xanthomonas campestris pv. campestris, Alone and in Association with a Phage | Xanthomonadaceae plant diseases | Scoop.it
Biofilm protects bacteria against the host’s immune system and adverse environmental conditions. Several studies highlight the efficacy of lytic phages in the prevention and eradication of bacterial biofilms. In this study, the lytic activity of Xccφ1 (Xanthomonas campestris pv. campestris-specific phage) was evaluated in combination with 6-pentyl-α-pyrone (a secondary metabolite produced by Trichoderma atroviride P1) and the mineral hydroxyapatite. Then, the antibiofilm activity of this interaction, called a φHA6PP complex, was investigated using confocal laser microscopy under static and dynamic conditions. Additionally, the mechanism used by the complex to modulate the genes (rpf, gumB, clp and manA) involved in the biofilm formation and stability was also studied. Our results demonstrated that Xccφ1, alone or in combination with 6PP and HA, interfered with the gene pathways involved in the formation of biofilm. This approach can be used as a model for other biofilm-producing bacteria.
No comment yet.
Scooped by COST Action CA16107
Scoop.it!

Complete genome sequence of Xylella taiwanensis and comparative analysis of virulence gene content with Xylella fastidiosa | bioRxiv

bioRxiv - the preprint server for biology, operated by Cold Spring Harbor Laboratory, a research and educational institution
No comment yet.
Scooped by COST Action CA16107
Scoop.it!

Huanglongbing and citrus variegated chlorosis integrated management based on favorable periods for vector population increase and symptom expression | Plant Disease

Huanglongbing and citrus variegated chlorosis integrated management based on favorable periods for vector population increase and symptom expression | Plant Disease | Xanthomonadaceae plant diseases | Scoop.it
Huanglongbing (HLB, associated with ‘Candidatus Liberibacter asiaticus’ and transmitted by the Asian citrus psyllid Diaphorina citri) and citrus variegated chlorosis (CVC, caused by Xylell
No comment yet.
Scooped by COST Action CA16107
Scoop.it!

Genetic differentiation of Xylella fastidiosa following the introduction into Taiwan | bioRxiv

bioRxiv - the preprint server for biology, operated by Cold Spring Harbor Laboratory, a research and educational institution
No comment yet.
Scooped by COST Action CA16107
Scoop.it!

Aggressiveness of Spanish isolates of Xylella fastidiosa to almond plants of different cultivars under greenhouse conditions | Phytopathology®

Aggressiveness of Spanish isolates of Xylella fastidiosa to almond plants of different cultivars under greenhouse conditions | Phytopathology® | Xanthomonadaceae plant diseases | Scoop.it
The aggressiveness of Spanish isolates of X. fastidiosa, representing different sequence types, were studied in almond plants of several cultivars by means of the dynamics of the population level
No comment yet.
Scooped by COST Action CA16107
Scoop.it!

Frontiers | Evaluation of Established Methods for DNA Extraction and Primer Pairs Targeting 16S rRNA Gene for Bacterial Microbiota Profiling of Olive Xylem Sap | Plant Science

Frontiers | Evaluation of Established Methods for DNA Extraction and Primer Pairs Targeting 16S rRNA Gene for Bacterial Microbiota Profiling of Olive Xylem Sap | Plant Science | Xanthomonadaceae plant diseases | Scoop.it
Next-generation sequencing has revolutionized our ability to investigate the microbiota composition of diverse and complex environments. However, a number of factors can affect the accuracy of microbial community assessment, such as the DNA extraction method, the hypervariable region of 16S rRNA gene targeted, or the PCR primers used for amplification. The aim of this study was to assess the influence of commercially available DNA extraction kits and different primer pairs to provide a non-biased vision of the composition of bacterial communities present in olive xylem sap. For that purpose, branches from “Picual” and “Arbequina” olive cultivars were used for xylem sap extraction using a Scholander chamber device. The DNA extraction protocol significantly affected xylem sap bacterial community assessment. That resulted in significant differences in alpha (Richness) and beta diversity (UniFrac distances) metrics among DNA extraction protocols, with the 12 DNA extraction kits evaluated being clustered in four groups behaving differently. Although the core number of taxa detected by all DNA extraction kits included four phyla, seven classes, 12 orders, 16 or 21 families, and 12 or 14 genera when using the Greengenes or Silva database for taxonomic assignment, respectively, some taxa, particularly those identified at low frequency, were detected by some DNA extraction kits only. The most accurate depiction of a bacterial mock community artificially inoculated on sap sample
No comment yet.
Scooped by COST Action CA16107
Scoop.it!

Microorganisms | Free Full-Text | Phenotypic Characterization and Transformation Attempts Reveal Peculiar Traits of Xylella fastidiosa Subspecies pauca Strain De Donno

Microorganisms | Free Full-Text | Phenotypic Characterization and Transformation Attempts Reveal Peculiar Traits of Xylella fastidiosa Subspecies pauca Strain De Donno | Xanthomonadaceae plant diseases | Scoop.it
Xylella fastidiosa subsp. pauca strain De Donno has been recently identified as the causal agent of a severe disease affecting olive trees in a wide area of the Apulia Region (Italy). While insights on the genetics and epidemiology of this virulent strain have been gained, its phenotypic and biological traits remained to be explored. We investigated in vitro behavior of the strain and compare its relevant biological features (growth rate, biofilm formation, cell–cell aggregation, and twitching motility) with those of the type strain Temecula1. The experiments clearly showed that the strain De Donno did not show fringe on the agar plates, produced larger amounts of biofilm and had a more aggregative behavior than the strain Temecula1. Repeated attempts to transform, by natural competence, the strain De Donno failed to produce a GFP-expressing and a knockout mutant for the rpfF gene. Computational prediction allowed us to identify potentially deleterious sequence variations most likely affecting the natural competence and the lack of fringe formation. GFP and rpfF- mutants were successfully obtained by co-electroporation in the presence of an inhibitor of the type I restriction–modification system. The availability of De Donno mutant strains will open for new explorations of its interactions with hosts and insect vectors.
No comment yet.
Scooped by COST Action CA16107
Scoop.it!

Pathogens | Free Full-Text | Orthology-Based Estimate of the Contribution of Horizontal Gene Transfer from Distantly Related Bacteria to the Intraspecific Diversity and Differentiation of Xylella f...

Pathogens | Free Full-Text | Orthology-Based Estimate of the Contribution of Horizontal Gene Transfer from Distantly Related Bacteria to the Intraspecific Diversity and Differentiation of Xylella f... | Xanthomonadaceae plant diseases | Scoop.it
Xylella fastidiosa is a xylem-limited bacterium phylogenetically related to the xanthomonads, with an unusually large and diversified range of plant hosts. To ascertain the origin of its peculiarities, its pan-genome was scanned to identify the genes that are not coherent with its phylogenetic position within the order Xanthomonadales. The results of the analysis revealed that a large fraction of the genes of the Xylella pan-genome have no ortholog or close paralog in the order Xanthomonadales. For a significant part of the genes, the closest homologue was found in bacteria belonging to distantly related taxonomic groups, most frequently in the Betaproteobacteria. Other species, such as Xanthomonas vasicola and Xanthomonas albilineans which were investigated for comparison, did not show a similar genetic contribution from distant branches of the prokaryotic tree of life. This finding indicates that the process of acquisition of DNA from the environment is still a relevant component of Xylella fastidiosa evolution. Although the ability of Xylella fastidiosa strains to recombine among themselves is well known, the results of the pan-genome analyses stressed the additional relevance of environmental DNA in shaping their genomes, with potential consequences on their phytopathological features.
No comment yet.
Scooped by COST Action CA16107
Scoop.it!

Pathogens | Free Full-Text | Further In Vitro Assessment and Mid-Term Evaluation of Control Strategy of Xylella fastidiosa subsp. pauca in Olive Groves of Salento (Apulia, Italy)

Pathogens | Free Full-Text | Further In Vitro Assessment and Mid-Term Evaluation of Control Strategy of Xylella fastidiosa subsp. pauca in Olive Groves of Salento (Apulia, Italy) | Xanthomonadaceae plant diseases | Scoop.it
During recent years; Xylella fastidiosa subsp. pauca (Xfp) has spread in Salento causing relevant damage to the olive groves. Measures to contain the spreading of the pathogen include the monitoring of the areas bordering the so-called “infected” zone and the tree eradication in case of positive detection. In order to provide a control strategy aimed to maintain the tree productivity in the infected areas, we further evaluated the in vitro and in planta mid-term effectiveness of a zinc-copper-citric acid biocomplex. The compound showed an in vitro bactericidal activity and inhibited the biofilm formation in representative strains of X. fastidiosa subspecies, including Xfp isolated in Apulia from olive trees. The field mid-term evaluation of the control strategy assessed by quantitative real-time PCR in 41 trees of two olive groves of the “infected” area revealed a low concentration of Xfp over the seasons upon the regular spraying of the biocomplex over 3 or 4 consecutive years. In particular, the bacterial concentration lowered in July and October with respect to March, after six consecutive treatments. The trend was not affected by the cultivar and it was similar either in the Xfp-sensitive cultivars Ogliarola salentina and Cellina di Nardò or in the Xfp-resistant Leccino. Moreover, the scoring of the number of wilted twigs over the seasons confirmed the trend. The efficacy of the treatment in the management of olive groves subjected to a high pathogen pressure is highlighted by the yielded a good oil production
No comment yet.
Scooped by COST Action CA16107
Scoop.it!

Control of Pierce’s Disease Through Areawide Management of Glassy-Winged Sharpshooter (Hemiptera: Cicadellidae) and Roguing of Infected Grapevines | Journal of Integrated Pest Management | Oxford A...

Control of Pierce’s Disease Through Areawide Management of Glassy-Winged Sharpshooter (Hemiptera: Cicadellidae) and Roguing of Infected Grapevines | Journal of Integrated Pest Management | Oxford A... | Xanthomonadaceae plant diseases | Scoop.it
Abstract. The General Beale Pilot Project serves as a case study for the use of areawide monitoring and treatment programs for glassy-winged sharpshooter (GWSS)
No comment yet.
Scooped by COST Action CA16107
Scoop.it!

Genetic Diversity of Xylella fastidiosa in Mexican Vineyards | Plant Disease

Xylella fastidiosa is a xylem-inhabiting phytopathogenic bacterium that affects diverse agriculturally relevant crops. In Mexico, X. fastidiosa has been reported in the states of Baja California
No comment yet.
Scooped by COST Action CA16107
Scoop.it!

Microorganisms | Free Full-Text | Trends in Molecular Diagnosis and Diversity Studies for Phytosanitary Regulated Xanthomonas

Microorganisms | Free Full-Text | Trends in Molecular Diagnosis and Diversity Studies for Phytosanitary Regulated Xanthomonas | Xanthomonadaceae plant diseases | Scoop.it
Bacteria in the genus Xanthomonas infect a wide range of crops and wild plants, with most species responsible for plant diseases that have a global economic and environmental impact on the seed, plant, and food trade. Infections by Xanthomonas spp. cause a wide variety of non-specific symptoms, making their identification difficult. The coexistence of phylogenetically close strains, but drastically different in their phenotype, poses an added challenge to diagnosis. Data on future climate change scenarios predict an increase in the severity of epidemics and a geographical expansion of pathogens, increasing pressure on plant health services. In this context, the effectiveness of integrated disease management strategies strongly depends on the availability of rapid, sensitive, and specific diagnostic methods. The accumulation of genomic information in recent years has facilitated the identification of new DNA markers, a cornerstone for the development of more sensitive and specific methods. Nevertheless, the challenges that the taxonomic complexity of this genus represents in terms of diagnosis together with the fact that within the same bacterial species, groups of strains may interact with distinct host species demonstrate that there is still a long way to go. In this review, we describe and discuss the current molecular-based methods for the diagnosis and detection of regulated Xanthomonas, taxonomic and diversity studies in Xanthomonas and genomic approaches for molecular diagnosis.
No comment yet.
Scooped by COST Action CA16107
Scoop.it!

The Xanthomonas type-III effector protein XopS stabilizes CaWRKY40a to regulate defense hormone responses and preinvasion immunity in pepper (Capsicum annuum) | bioRxiv

bioRxiv - the preprint server for biology, operated by Cold Spring Harbor Laboratory, a research and educational institution
No comment yet.
Scooped by COST Action CA16107
Scoop.it!

Production of bioelectricity may play an important role for the survival of Xanthomonas campestris pv. campestris (Xcc) under anaerobic conditions - ScienceDirect

Production of bioelectricity may play an important role for the survival of Xanthomonas campestris pv. campestris (Xcc) under anaerobic conditions - ScienceDirect | Xanthomonadaceae plant diseases | Scoop.it
The plant pathogen Xanthomonas is commonly found in biocontaminated bioreactors; however, few studies have evaluated the growth and impacts of this mi…
No comment yet.
Scooped by COST Action CA16107
Scoop.it!

Evidence of gene nucleotide composition favoring replication and growth in a fastidious plant pathogen | G3 Genes|Genomes|Genetics | Oxford Academic

Evidence of gene nucleotide composition favoring replication and growth in a fastidious plant pathogen | G3 Genes|Genomes|Genetics | Oxford Academic | Xanthomonadaceae plant diseases | Scoop.it
Abstract. Nucleotide composition (GC content) varies across bacteria species, genome regions, and specific genes. In Xylella fastidiosa, a vector-borne fastidio
No comment yet.
Scooped by COST Action CA16107
Scoop.it!

Functional foregut anatomy of the blue–green sharpshooter illustrated using a 3D model

Functional foregut anatomy of the blue–green sharpshooter illustrated using a 3D model | Xanthomonadaceae plant diseases | Scoop.it
Sharpshooter leafhoppers (Hemiptera: Cicadellidae: Cicadellinae) are important vectors of the plant pathogenic bacterium Xylella fastidiosa Wells et al. (Xanthomonadales: Xanthomonadaceae). This pathogen causes economically significant diseases in olive, citrus, and grapes on multiple continents. Bacterial acquisition and inoculation mechanisms are linked to X. fastidiosa biofilm formation and fluid dynamics in the functional foregut of sharpshooters, which together result in egestion (expulsion) of fluids likely carrying bacteria. One key X. fastidiosa vector is the blue–green sharpshooter, Graphocephala atropunctata (Signoret, 1854). Herein, a 3D model of the blue–green sharpshooter functional foregut is derived from a meta-analysis of published microscopy images. The model is used to illustrate preexisting and newly defined anatomical terminology that is relevant for investigating fluid dynamics in the functional foregut of sharpshooters. The vivid 3D illustrations herein and supplementary interactive 3D figures are suitable resources for multidisciplinary researchers who may be unfamiliar with insect anatomy. The 3D model can also be used in future fluid dynamic simulations to better understand acquisition, retention, and inoculation of X. fastidiosa. Improved understanding of these processes could lead to new targets for preventing diseases caused by X. fastidiosa.
No comment yet.
Scooped by COST Action CA16107
Scoop.it!

Inoculum reduction and vector control on the temporal progress of citrus variegated chlorosis incidence - Bassanezi - - Pest Management Science

Inoculum reduction and vector control on the temporal progress of citrus variegated chlorosis incidence - Bassanezi - - Pest Management Science | Xanthomonadaceae plant diseases | Scoop.it

BACKGROUND
Citrus variegated chlorosis (CVC) is an important citrus disease caused by the sharpshooter‐transmitted bacterium Xylella fastidiosa subsp. pauca. Information about the efficacy of it
No comment yet.
Scooped by COST Action CA16107
Scoop.it!

Genomic insights advance the fight against black rot of crucifers | SpringerLink

Genomic insights advance the fight against black rot of crucifers | SpringerLink | Xanthomonadaceae plant diseases | Scoop.it
Xanthomonas campestris pv. campestris, the causal agent of black rot of crucifers, was one of the first bacterial plant pathogens ever identified. Over 130 years later, black rot remains a threat to cabbage, cauliflower, and other Brassica crops around the world. Recent genomic and genetic data are informing our understanding of X. campestris taxonomy, dissemination, inoculum sources, and virulence factors. This new knowledge promises to positively impact resistance breeding of Brassica varieties and management of inoculum sources.
No comment yet.
Scooped by COST Action CA16107
Scoop.it!

Overexpression of Citrus reticulata SAMT in Nicotiana tabacum increases MeSA volatilization and decreases Xylella fastidiosa symptoms | SpringerLink

Overexpression of Citrus reticulata SAMT in Nicotiana tabacum increases MeSA volatilization and decreases Xylella fastidiosa symptoms | SpringerLink | Xanthomonadaceae plant diseases | Scoop.it
Main conclusion Nicotiana tabacum overexpressing CrSAMT from Citrus reticulata increased production of MeSA, which works as an airborne signal in neighboring wild-type plants, inducing PR1 and increasing resistance to the pathogen Xylella fastidiosa. Abstract Xylella fastidiosa is one of the major threats to plant health worldwide, affecting yield in many crops. Despite many efforts, the development of highly productive resistant varieties has been challenging. In studying host plant resistance, the S-adenosyl-l-methionine: salicylic acid carboxyl methyltransferase gene (SAMT) from Citrus reticulata, a X. fastidiosa resistant species, was upregulated in response to pathogen infection. SAMT is involved with the catalysis and production of methyl salicylate (MeSA), an airborne signal responsible for triggering systemic acquired resistance. Here we used tobacco as a model system and generated transgenic plants overexpressing C. reticulata SAMT (CrSAMT). We performed an in silico structural characterization of CrSAMT and investigated its biotechnological potential in modulating the immune system in transgenic plants. The increase of MeSA production in transgenic lines was confirmed by gas chromatography (GC–MS). The transgenic lines showed upregulation of PR1, and their incubation with neighboring wild-type plants activated PR1 expression, indicating that MeSA worked as an airborne signal. In addition, transgenic plants showed significantly fewer symptoms when challenged with X. fastidiosa. Altogether, these data suggest that CrSAMT plays a role in host defense response and can be used in biotechnology approaches to confer resistance against X. fastidiosa.
No comment yet.
Scooped by COST Action CA16107
Scoop.it!

Seasonal Abundance and Infectivity of Philaenus spumarius (Hemiptera: Aphrophoridae), a Vector of Xylella fastidiosa in California Vineyards | Environmental Entomology | Oxford Academic

Seasonal Abundance and Infectivity of Philaenus spumarius (Hemiptera: Aphrophoridae), a Vector of Xylella fastidiosa in California Vineyards | Environmental Entomology | Oxford Academic | Xanthomonadaceae plant diseases | Scoop.it
Abstract. The meadow spittlebug, Philaenus spumarius (Linnaeus) (Hemiptera: Aphrophoridae), is a vector of the plant pathogen Xylella fastidiosa; however, its r
No comment yet.
Scooped by COST Action CA16107
Scoop.it!

Shape and rate of movement of the invasion front of Xylella fastidiosa spp. pauca in Puglia

Shape and rate of movement of the invasion front of Xylella fastidiosa spp. pauca in Puglia | Xanthomonadaceae plant diseases | Scoop.it
In 2013, Xylella fastidiosa spp. pauca was first reported in Puglia, Italy, causing the olive quick decline syndrome (OQDS). Since then the disease has spread, prompting the initiation of management measures to contain the outbreak. Estimates of the shape of the disease front and the rate of area expansion are needed to inform management, e.g. the delineation of buffer zones. However, empirical estimates of the invasion front and the rate of spread of OQDS are not available. Here, we analysed the hundreds of thousands of records of monitoring data on disease occurrence in Puglia to estimate the shape of the invasion front and the rate of movement of the front. The robustness of estimation was checked using simulation. The shape of the front was best fitted by a logistic function while using a beta-binomial error distribution to model variability around the expected proportion of infected trees. The estimated rate of movement of the front was 10.0 km per year (95% confidence interval: 7.5–12.5 km per year). This rate of movement is at the upper limit of previous expert judgements. The shape of the front was flatter than expected. The fitted model indicates that the disease spread started approximately in 2008. This analysis underpins projections of further disease spread and the need for preparedness in areas that are still disease free.
No comment yet.