Genetic Signatures of Contrasted Outbreak Histories of " Liberibacter asiaticus", the Bacterium That Causes Citrus Huanglongbing, in Three Outermost Regions of the European Union.

In an era of trade globalization and climate change, crop pathogens and pests are a genuine threat to food security. The detailed characterization of emerging pathogen populations is a prerequisite for managing invasive species pathways and designing sustainable disease control strategies. Huanglongbing is the disease that causes the most damage to citrus, a crop that ranks #1 worldwide in terms of fruit production.

New, complete circularized genomes of pv. produced from short- and long-read co-assembly shed light on strains that emerged a decade ago on mango and cashew in Burkina Faso.

We report high-quality genomes of three strains of pv. (), the causal agent of mango bacterial canker disease, including the pathotype strain of this pathovar and two strains from Burkina Faso that emerged a decade ago. These strains hosted two to three plasmids of sizes ranging from 19 to 86 kb.

Evolutionary and Epidemiological Insights from Historical and Modern Genomes of pv. , the Causal Agent of Bacterial Leaf Streak of Rice.

pv. () causes bacterial leaf streak (BLS) of rice. This disease represents a major constraint for rice production, which is a crop feeding more than half of the world's population.

Comparative transcriptomics reveals a highly polymorphic Xanthomonas HrpG virulence regulon.

Background: Bacteria of the genus Xanthomonas cause economically significant diseases in various crops. Their virulence is dependent on the translocation of type III effectors (T3Es) into plant cells by the type III secretion system (T3SS), a process regulated by the master response regulator HrpG. Although HrpG has been studied for over two decades, its regulon across diverse Xanthomonas species, particularly beyond type III secretion, remains understudied.

Phylodynamic Insights into Global Emergence and Diversification of the Tomato Pathogen pv. .

The emergence of plant pathogens is often associated with waves of unique evolutionary and epidemiological events. pv. is one of the major pathogens causing bacterial spot disease of tomatoes.

Complete Genome Sequence of a Copper-Resistant pv Strain Isolated from Broccoli in Mauritius Suggests Adaptive Gene Gain Through Horizontal Gene Transfer.

Bacterial adaptation is facilitated by the presence of mobile genetic elements and horizontal gene transfer of genes, such as those coding for virulence factors or resistance to antimicrobial compounds. A hybrid assembly of Nanopore MinIon long-read and Illumina short-read data was produced from a copper-resistant pv.  strain isolated from symptomatic broccoli leaves in Mauritius.

Herbarium specimen sequencing allows precise dating of Xanthomonas citri pv. citri diversification history.

Herbarium collections are an important source of dated, identified and preserved DNA, whose use in comparative genomics and phylogeography can shed light on the emergence and evolutionary history of plant pathogens. Here, we reconstruct 13 historical genomes of the bacterial crop pathogen Xanthomonas citri pv. citri (Xci) from infected Citrus herbarium specimens.

A minisatellite-based MLVA for deciphering the global epidemiology of the bacterial cassava pathogen Xanthomonas phaseoli pv. manihotis.

Cassava Bacterial Blight (CBB) is a destructive disease widely distributed in the different areas where this crop is grown. Populations studies have been performed at local and national scales revealing a geographical genetic structure with temporal variations. A global epidemiology analysis of its causal agent Xanthomonas phaseoli pv.

Suspicions of two bridgehead invasions of Xylella fastidiosa subsp. multiplex in France.

Of American origin, a wide diversity of Xylella fastidiosa strains belonging to different subspecies have been reported in Europe since 2013 and its discovery in Italian olive groves. Strains from the subspecies multiplex (ST6 and ST7) were first identified in France in 2015 in urban and natural areas. To trace back the most probable scenario of introduction in France, the molecular evolution rate of this subspecies was estimated at 3.

Molecular Epidemiology of Phylotype I Strains in the Southwest Indian Ocean Region and Their Relatedness to African Strains.

The increasing requirement for developing tools enabling fine strain traceability responsible for epidemics is tightly linked with the need to understand factors shaping pathogen populations and their environmental interactions. Bacterial wilt caused by the species complex (RSSC) is one of the most important plant diseases in tropical and subtropical regions. Sadly, little, outdated, or no information on its epidemiology is reported in the literature, although alarming outbreaks are regularly reported as disasters.

Molecular epidemiology of the citrus bacterial pathogen pv. from the Arabian Peninsula reveals a complex structure of specialist and generalist strains.

Molecular epidemiology studies are essential to refine our understanding of migrations of phytopathogenic bacteria, the major determining factor in their emergence, and to understand the factors that shape their population structure. Microsatellite and minisatellite typing are useful techniques for deciphering the population structure of pv. , the causal agent of Asiatic citrus canker.

Pathotyping Citrus Ornamental Relatives with pv. and pv. Refines Our Understanding of Their Susceptibility to These Pathogens.

pv. () and pv. () are causal agents of Citrus Bacterial Canker (CBC), a devastating disease that severely affects citrus plants.

A network approach to decipher the dynamics of Lysobacteraceae plasmid gene sharing.

Plasmids provide an efficient vehicle for gene sharing among bacterial populations, playing a key role in bacterial evolution. Network approaches are particularly suitable to represent multipartite relationships and are useful tools to characterize plasmid-mediated gene sharing events. The bacterial family Lysobacteraceae includes plant commensal, plant pathogenic and opportunistic human pathogens for which plasmid-mediated adaptation has been reported.

First historical genome of a crop bacterial pathogen from herbarium specimen: Insights into citrus canker emergence.

Over the past decade, ancient genomics has been used in the study of various pathogens. In this context, herbarium specimens provide a precious source of dated and preserved DNA material, enabling a better understanding of plant disease emergences and pathogen evolutionary history. We report here the first historical genome of a crop bacterial pathogen, Xanthomonas citri pv.

Diversity and Geographical Structure of pv. on Citrus in the South West Indian Ocean Region.

A thorough knowledge of genotypic and phenotypic variations (e.g., virulence, resistance to antimicrobial compounds) in bacteria causing plant disease outbreaks is key for optimizing disease surveillance and management.

Trends in Molecular Diagnosis and Diversity Studies for Phytosanitary Regulated .

Bacteria in the genus 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 spp. cause a wide variety of non-specific symptoms, making their identification difficult.

Draft Genome Sequences of 284 Xanthomonas citri pv. citri Strains Causing Asiatic Citrus Canker.

High-quality Illumina assemblies were produced from 284 pv. citri pathotype A strains mostly originating from the Southwest Indian Ocean region, a subset of which was also sequenced using MinION technology. Some strains hosted chromosomally encoded transcription activator-like effector (TALE) genes, an atypical feature for this bacterium.

Time-calibrated genomic evolution of a monomorphic bacterium during its establishment as an endemic crop pathogen.

Horizontal gene transfer is of major evolutionary importance as it allows for the redistribution of phenotypically important genes among lineages. Such genes with essential functions include those involved in resistance to antimicrobial compounds and virulence factors in pathogenic bacteria. Understanding gene turnover at microevolutionary scales is critical to assess the pace of this evolutionary process.

Development and comparative validation of genomic-driven PCR-based assays to detect Xanthomonas citri pv. citri in citrus plants.

Background: Asiatic Citrus Canker, caused by Xanthomonas citri pv. citri, severely impacts citrus production worldwide and hampers international trade. Considerable regulatory procedures have been implemented to prevent the introduction and establishment of X.

CRISPR elements provide a new framework for the genealogy of the citrus canker pathogen Xanthomonas citri pv. citri.

Background: Xanthomonads are an important clade of Gram-negative bacteria infecting a plethora of economically important host plants, including citrus. Knowledge about the pathogen's diversity and population structure are prerequisite for epidemiological surveillance and efficient disease management. Rapidly evolving genetic loci, such as Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR), are of special interest to develop new molecular typing tools.

Deciphering how plant pathogenic bacteria disperse and meet: Molecular epidemiology of pv. at microgeographic scales in a tropical area of Asiatic citrus canker endemicity.

Although some plant pathogenic bacteria represent a significant threat to agriculture, the determinants of their ecological success and evolutionary potential are still poorly understood. Refining our understanding of bacterial strain circulation at small spatial scales and the biological significance and evolutionary consequences of co-infections are key questions. The study of bacterial population biology can be challenging, because it requires high-resolution markers that can be genotyped with a high throughput.

A duplex quantitative real-time PCR assay for the detection and quantification of Xanthomonas phaseoli pv. dieffenbachiae from diseased and latently infected anthurium tissue.

Anthurium bacterial blight caused by Xanthomonas phaseoli pv. dieffenbachiae (formerly Xanthomonas axonopodis pv. dieffenbachiae) is the major phytosanitary threat in many anthurium growing areas worldwide.

Molecular Epidemiology of Bacterial Wilt in the Madagascar Highlands Caused by Andean (Phylotype IIB-1) and African (Phylotype III) Brown Rot Strains of the Species Complex.

The species complex (RSSC) is a highly diverse cluster of bacterial strains found worldwide, many of which are destructive and cause bacterial wilt (BW) in a wide range of host plants. In 2009, potato production in Madagascar was dramatically affected by several BW epidemics. Controlling this disease is critical for Malagasy potato producers.

as a host of citrus bacterial canker.

Following a request from the European Commission, the European Food Safety Authority (EFSA) Plant Health (PLH) Panel analysed a dossier submitted by the Japanese authorities in order to clarify the host status of with regard to pv. and pv. , causal agents of citrus bacterial canker, and to indicate whether fruit could represent a pathway for the introduction of citrus bacterial canker into the European Union.

Complete Genome Sequences of Six Copper-Resistant pv. citri Strains Causing Asiatic Citrus Canker, Obtained Using Long-Read Technology.

The gammaproteobacterium pv citri causes Asiatic citrus canker. Pathotype A strains have a broad host range, which includes most commercial citrus species, and they cause important economic losses worldwide. Control often relies on frequent copper sprays.