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Article

Comparative Genomic Analysis of Phytopathogenic Xanthomonas Species Suggests High Level of Genome Plasticity Related to Virulence and Host Adaptation

by
Juan Carlos Ariute
1,2,
Diego Lucas Neres Rodrigues
3,
Siomar de Castro Soares
4,
Vasco Azevedo
3,
Ana Maria Benko-Iseppon
1,*,† and
Flávia Figueira Aburjaile
2,*,†
1
Genetics Department, Universidade Federal de Pernambuco, Recife 50740-600, Brazil
2
Preventive Veterinary Medicine Departament, Veterinary School, Universidade Federal de Minas Gerais, Belo Horizonte 31270-901, Brazil
3
Genetics, Ecology and Evolution Department, Universidade Federal de Minas Gerais, Belo Horizonte 31270-901, Brazil
4
Institute of Biological and Natural Sciences, Universidade Federal do Triângulo Mineiro, Uberaba 38025-180, Brazil
*
Authors to whom correspondence should be addressed.
These authors contributed equally to this work.
Bacteria 2022, 1(4), 218-241; https://doi.org/10.3390/bacteria1040017
Submission received: 19 July 2022 / Revised: 23 September 2022 / Accepted: 27 September 2022 / Published: 8 October 2022

Abstract

:
Xanthomonas bacteria are known phytopathogens difficult to control in the field, which cause great losses in many economically important crops. Genomic islands are fragments acquired by horizontal transference that are important for evolution and adaptation to diverse ecological niches. Virulence and pathogenicity islands (PAIs) enhance molecular mechanisms related to host adaptation. In this work, we have analyzed 81 genomes belonging to X. campestris, and a complex group of X. citri, X. axonopodis, and X. fuscans belonging to nine different pathovars and three subspecies, to analyze and compare their genomic contents. Xanthomonas pan-genome is open and has a massive accessory genome. Each genome showed between three and 15 exclusive PAIs, well conserved through strains of the same pathovar or subspecies. X. axonopodis pv. anacardii had higher general similarity to X. citri subsp. citri and X. fuscans subsp. aurantifolii, with which a few PAIs were shared. Genomic synteny was even for almost all strains, with few rearrangements found in X. axonopodis pv. anacardii. The prophage regions identified in the genomes were mostly questionable or incomplete, and PAI13 in X. campestris pv. campestris ATCC33913 matched a prophage region of 19 transposable elements. Finally, PAIs in Xanthomonas are pathovar-specific, requiring individual strategies of combat.

1. Introduction

Bacteria of the genus Xanthomonas affect several crops of economic importance, responsible for diseases such as bacterial black spot, citrus canker, and the bacterial canker of grapevine, for instance [1,2]. Even though these phytobacterioses cause considerable economic losses [3], there is still no adequate method to control their spread and reduce disease incidence in agriculture, specially those associated with X. campestris and X. citri [4,5,6,7]. Studies regarding this and other Xanthomonas species, revealed the enormous potential of comparative genomics approaches focused on the accessory genome and mobile elements to elucidate aspects of pathogenicity explicitly assigned to adaptive traits, cell physiology, and host specificity [8,9,10,11,12]. When applied to different pathovars of the same species, this type of approach aids in plant-host relationship studies, since it is possible to identify specific genes and metabolic pathways based on the genome structure and composition as well [13]. Consequently, studies for the identification and characterization of virulence factors and protein effectors shared with different strains of the same species allow the discovery of specific genomic profiles suggesting an increased or reduced virulence for a given host [14,15,16].
Previous studies based on the morphology and other phenotypic characteristics of Xanthomonas have misclassified it taxonomically, such as strains that infect grape, cashew, and mango crops, amongst others [17]. As whole genome-based techniques were improved, topologies in the Xanthomonas genus were changed in many species. For instance, whole-genome sequencing, DNA–DNA hybridization and multilocus analyses in strains of X. axonopodis have shown biased taxonomy in species, subspecies, and pathovar levels, supporting reclassification to X. citri pv. anacardii X. citri pv. vignicola, and X. citri pv. glycines instead [18]. Moreover, other phylogenies confirmed with these new topologies, reclassifying X. fuscans as a pathovar of X. citri, and X. albilineans would form a joint clade linking the Xanthomonas genus to Xyllela fastidiosa [19]. Similarly, recent phylogenetic and ANI (average nucleotide identity) analyses have supported transference of X. campestris pv. arecae and X. campestris pv. musacearum strains to X. vasicola [20].
Even though those species might be similar, it has not yet been elucidated how similar their genomic features as a whole might be, including the dispersion of molecular features related to pathogenicity. Thereby, this study aims to understand the influence of the genomic content of the X. citri complex and X. campestris on virulence, pathogenicity, and the specific host–pathogen correlation.

2. Materials and Methods

2.1. Genome Annotation of Xanthomonas species

We obtained 80 complete genomes from the National Centre for Biotechnology Information (NCBI) belonging to X. citri and X. campestris species. The genomes of those species were selected due to the interest of the research group in species that affect agriculture in Northeast Brazil. All genomes are listed in Table A1, according to their strain, isolation source, and related disease.

2.2. Genomic Characterization and Enrichment Analysis

Initially, all genomes were automatically annotated by Rapid Annotation using Subsystem Technology (RAST) performed to predict putative CDSs, tRNA, and rRNA regions [21]. Subsequently, we used the Artemis tool [22] for manual gene characterization according to alignments done at UniProt, Pfam, and InterProScan databases. To carry out genetic enrichment, we used the Gene Ontology Functional Enrichment Annotation Tool (GO Feat) [23] for the characterization of genes and proteins at three different ontological levels (molecular function, biological process, cellular component) of all 80 genomes of Xanthomonas strains. We also used the Kyoto Encyclopedia of Genes and Genomes (KEGG) [24] to characterize metabolic pathways for both pangenomes and individual sets of genomes. We only performed the characterization for individual sets of genomes to X. citri and X. campestris, due to the low number of representative X. vasicola genomes available.

2.3. Pan-Genome Analyses

For the pan-genome analyses, we used Bacterial Pan-Genome Analyses pipeline (BPGA) [25] to identify clusters of orthologous sequences (COG) among Xanthomonas genomes. We also used Roary [26] for phylogenomic inference and FigTree [27] for phylogenomic tree visualization. Finally, we used the Virulence Factor Database (VFDB) [28] to determine a cluster map of virulence factors throughout all Xanthomonas genomes.

2.4. Prediction and Characterization of Pathogenicity Islands

We used the Genomic Island Prediction Software (GIPSy) tool [29], which is one of the most cited and recommended tools in the literature [30], to obtain genomic islands in all genomes, focusing on pathogenicity islands (PAIs). Then, we added and correlated GO terms to CDS in each pathogenicity island in X. citri and X. campestris strains. In this step, we only considered exclusive PAIs, since many regions were associated with more than one type of genomic island (metabolic, resistance, or symbiotic). We used BLAST Ring Image Generation (BRIG) [31] to represent and evaluate the position of genomic islands in different strains of Xanthomonas, as well as the similarity between strains of the same and different pathovars and/or subspecies. To understand island distribution and conservation through different genomes, the graphs were plotted using representative pathovars, each with a reference strain, so that the relationships between PAIs and hosts would be easier to approach. We chose genomes with the highest number of PAIs as representative genomes for each pathovar. The faded regions in the rings denoted lower similarity (<70%) whilst strong colors denoted higher similarity (>90%). We also used the MAUVE tool [32] to identify probable genomic rearrangements among strains of interest by comparing strain-specific regions correlated with genomic islands of reference strains and checking if there were any disruption, change of location, or change of sense between different strains.

2.5. Subcellular Localization of Proteins inside PAIs

The online platform PSORTb v.3 [33] was used to predict the subcellular location of the coding sequences products inside pathogenicity islands of interest. Specific multifasta files were manually created for each island of interest, with sequences available in the Artemis interface.

2.6. Prediction of Prophages Regions in Xanthomonas genomes

We performed a comparison of prophage regions between different pathogens using PHASTER [34]. This tool identified and classified each prophage region in representative pathovars of X. citri and X. campestris according to scoring in three categories: intact (score green > 90), questionable (score blue 70–90), and incomplete (score red < 70).

3. Results

3.1. Functional Genomics and Comparative Genomics Insights of Xanthomonas species

All 80 genomes presented around 65% GC content, all relevant information regarding strains is available in Table A1. The automatic annotation on RAST predicted 4287 coding sequences (CDS) in the selected reference genome X. campestris pv. campestris ATCC 33913. The GO results for all 80 strains’ genomes showed that most proteins are involved in molecular functions, representing a percentage higher than 1/3 of the total protein repertoire. The other two categories, biological processes and cellular components ranged from 1925 to 2223 and 1509 to 1813 proteins, respectively (Figure S1). Overall, the COG profile of both X. campestris and X. citri were very similar. Categories of general or unknown function (R and S) had the highest percentages (around 40% and 20%, respectively)in the core, accessory, and unique genomes of these two species, possibly due to the lack of studies on the functional characterization of representative genomes. Other categories of COG with considerable percentages of genes were related to (1) cell wall/membrane/envelope and biogenesis, (2) signal transduction mechanisms, (3) intracellular trafficking, secretion, and vesicular transport, and (4) transcription (Figure S2). For the pan-genome analysis, the distribution of unique, accessory, and core genomes among the categories was almost uniform, except for nucleotide transport and metabolism, in which no unique genes were identified for X. citri, and a small portion of unique with no accessory genes found for X. campestris (Figure S2). Roary prediction of genome shows that the accessory genome of Xanthomonas had a higher number of genes compared to the core and unique genomes, corroborating with BPGA analysis (Figure S3) (Table 1). Moreover, BPGA results indicate the pan-genome is still open, as the alpha value was lower than 1. However, as the curve flattened and stabilized with the increasing number of genomes added to the analysis, it may be closed soon enough, as seen in Figure 1.
Agreeing to that, the distribution of metabolic pathways on KEGG for the Xanthomonas pan-genome showed that some categories had more sequences belonging to the accessory genome than to the core, specifically categories that are somehow related to pathogenicity and virulence, such as cell motility, glycan biosynthesis and metabolism, infectious diseases, membrane transport, signal transduction, xenobiotics degradation and metabolism (Figure 2). General categories like cellular processes and environmental information processing also showed more genes related to the accessory pan-genome. The pan-genome matrix based on the core genome revealed that X. campestris exhibited clusters of genes different from the other species’ genomes (Figure S4). The core phylogenomic tree on this figure is also available in Figure S5.
Finally, the search for virulence factors revealed 14 genes present through the genomes, but only 4 were identified in all 81 genomes: htpB, pilG, cheY, and fliN. Other virulence factors such as pilT, vipB, clpV1, ugd, and vipA were also common for most of the genomes. Only the genomes of X. campestris pv. raphani 756C, X. citri subsp. malvacearum XcmN1005 and X. citri subsp. malvacearum MS14003 presented exclusive virulence factors fliA and pilC, respectively. A cluster map for all virulence factors is available in Figure S6.

3.2. Genomic Islands Reveal a New Potential Regarding the Pathogenicity of the Genus

All genomes analyzed presented PAIs, and most of them matched with genomic regions of GC content deviation. The genomes of X. campestris pv. campestris 17, X. citri pv. fuscans ISO118C5, X. citri pv. fuscans ISO118C3, X. citri pv. phaseoli var. fuscans CFBP6167 and X. citri pv. phaseoli var. fuscans CFBP6996R presented only three PAIs, making the lowest number found in this analysis. On the other hand, X. citri subsp. malvacearum XcmH1005 exhibited the highest quantity, with 15 exclusive PAIs. The total number of PAIs found for all genomes is available in Table A2. Most of the islands found on the genomes constituted CDSs annotated as hypothetical proteins, only being able to infer their function based on the enrichment analysis. Among the X. citri subsp. citri genomes, strain TX160197 exhibited the highest number of PAIs (14) and high genomic similarity with other strains, except for AW13, AW14, AW15, AW16, TX160042, and TX160149. Besides, all different strains from this subspecies exhibited similarity below 70% for PAI24 and gaps inside this genomic region (Figure 3). As for X. campestris, strain ATCC 33913 contained ten PAIs, of which most were highly conserved in this species’ strains, except for strain 17 and X. campestris pv. raphani 756C. As for X. vasicola pv. arecae NCPB2649 and X. vasicola pv. musacearum (Figure 4).
The previous scenario was similar for X. citri subsp. malvacearum: PAIs in the reference strain XcmH1005 had high conservation, although gap regions were present in large islands, such as PAI14 (Figure 5). However, in X. citri pv. phaseoli var. fuscans, almost all islands found in the selected reference strain CFBP7767 consisted of gap regions in the other strains of this pathovar, except for strains CFBP6992 and CFBP4885 (Figure 6), also similar to what was observed in genomes of X. citri pv. fuscans.
ForX. citri pv. aurantifolii genomes, strain FDC1559 presented 11 well-conserved and exclusive PAIs. Moreover, strain 1566 had a similarity of 100% with the reference genome (Figure 7). For X. citri pv. vignicola, X. citri pv. anacardii, X. axonopodis pv. vignicola, and X. axonopodis pv. anacardii, most of the PAIs identified in the reference genome were gap regions in the other strains (Figure 8). Finally, X. citri pv. glycines exhibited the highest conservation of pathogenicity islands among their strains (Figure 9).
As for interspecies comparisons, genomes of X. axonopodis pv. anacardii showed high genomic identity when compared against the genome of X. campestris pv. campestris ATCC 33913. However, none of the PAIs identified in the latter showed high conservation amongst X. axonopodis pv. anacardii genomes, as most of its PAIs, matched with significant genomic gaps (Figure 10). In contrast, PAIs found in X. citri subsp. citri TX160197 had higher conservation and similarity. Similar profiles were observed for PAIs in X. citri subsp. malvacearum Xcmh1005, X. citri pv. phaseoli var. fuscans CFBP7767, X. axonopodis pv. vignicola CFBP7111 and X. axonopodis pv. glycines 12-2. The highest similarity of PAIs was observed in comparison with the genome of X. fuscans subsp. aurantifolii FDC1559 (PAIs 6, 11, 12, and 28) (Figure 11).
Although some of these islands were conserved in different pathovars, they presented different levels of integrity. An example is CDS XCG122_1740, a virulence regulator located in PAI8 of X. citri pv. glycines 12-2, which suffered an inversion in X. citri pv. anacardii IBSBF2579 PAI6, corresponding to CDS IBSBF_1976 (Figure S7). On the other hand, some genomic islands exhibited exceptional conservation in certain strains of the same pathovar, exhibiting almost no changes, such as for PAI21 of X. citri pv. vignicola CFBP7111, CFBP7112, and CFBP7111 (Figure S8).

3.3. Cellular Localization and Ontology of Pathogenicity Islands

Most PAIs contained hypothetical proteins that were secondly annotated as putative virulence factors, such as sequences related to carbohydrate metabolic process (GO:0005975), hydrolase activity (GO:0016787), DNA-binding transcription factor activity (GO:0003700), and signaling receptor activity (GO:0038023).
Subcellular analysis of 28 well-conserved PAIs indicated that most proteins had cytoplasmic or unknown cellular localization. Only 119 coding sequences had different localizations, while only nine were described as extracellular proteins: three found in X. citri pv. anacardii IBSBF2579, one in X. citri pv. vignicola CFBP7111 and X. citri pv. aurantifolii FDC1559, and two in X. citri pv. glycines 12-2 and X. citri pv. fuscans ISO188C1 genomes. No extracellular proteins were found in well-conserved PAIs belonging to X. campestris or other X. citri genomes. Finally, five proteins were found for the outer membrane, and 15 proteins might be in multiple positions inside the cell. All the other proteins found were for cytoplasmic membrane location.

3.4. Prophage Regions, Transposable Elements and Their Relationship with Pathogenicity Islands

The highest numbers of prophage regions were observed in genomes of X. citri pv. aurantifolii strain FDC1609 (3 intact, 2 questionable and 7 incomplete), strain 1566 (2 intact, 2 questionable and 3 incomplete) and X. citri pv. vignicola CFBP7111 (4 intact and 4 incomplete). Regions that corresponded with many incomplete prophages were found in the genomes of X. campestris pv. raphani 756C (regions 1 and 3), X. campestris pv. campestris CN15 (regions 2 and 3), B100 (region 2), ICMP 21080 (region 4) and ICMP 4013 (region 12). Two regions of intact phages were detected in the genomes of X. vasicola pv. musacearum NCPPB 4379 and X. campestris pv. campestris 8004. The number of prophage regions found for each genome is available in Table A3.
Interestingly, some genomic islands and prophage regions overlapped. For instance, in the genome of X. campestris pv. campestris ATCC33913, PAI13, a genomic island of identity above 90% when compared against other genomes of the same species, comprehended mostly insertion sequences (IS) transposases and matched a region of an intact prophage. Those sequences belonged to the Isxcc1 and IS3 families (19 out of 23 CDSs), and others were annotated as phage-related proteins. The different sequences were putative virulence factors related to molecular functions, such as carbon-sulfur lyase activity (GO:0016846) and oxidoreductase activity (GO:0016491). In addition, many transposable elements in well-conserved PAIs were seen in PAIs 23 and 24 of X. citri subsp. citri TX160197, PAI4 of X. citri subsp. malvacearum AR81009 (which was well conserved in the genomes of strains XcmH1005 and XcmN1003, but not in MSCT and MS14003), and PAIs 11 and 12 of the X. citri subsp. malvacearum AR81009 PAI11. The genome of X. citri pv. phaseolis var. fuscans CFBP7767 showed sequences related to bacterial conjugation, pili, transposases, and virulence factors within PAI13. As for X. citri pv. anacardii IBSBF2579 genome, PAI8 was not only counted with many transposable elements but also a few putative virulence factors as well. However, this region did not match any prophage region detected in the genome, intact or not.

4. Discussion

4.1. Insights Provided by the Pan-Genome of Xanthomonas

Some pangenomics studies on certain species of Xanthomonas have been carried out to find out what makes strains more or less virulent. For instance, pan-genome tools have been addressed to aid in taxonomy revisions of X. arboricola, and also to find relationships between different lineages of Xanthomonas species based on the core genome [35,36,37]. Some effectors, such as TALEs and T3SEs, are present in most strains of X. citri pv. glycines, indicating a closed pan-genome due to low differences in genomic content [38,39]. For X. perforans, however, it has been found that most of the pan-genome is made of more than 4000 genes present in accessory genomes, indicating an open genome due to recombination mechanisms of this species [16]. Studies on the sister clade of Xanthomonas and Stenotrophomonas have shown that almost only 10% of the genes make part of a core genome of this genus [40]. In the present study, we described the pan-genome for the most representative species of the genus. We suggest the reason it is still open is due to a high diversity of accessory genomes, especially regarding their pathogenicity traits. These results open new perspectives for the study of evolutionary genomics of Xanthomonas, focusing on their accessory genomes.

4.2. Enrichment Analysis in Pathogenicity Islands

The genomic features annotation was more in-depth than in previous studies [41,42], considering mainly the number of identified pseudogenes. Moreover, the high percentage of unique genes with general or unknown functions in X. citri strains had already been associated with its wide range of diversification [43]. Two significant characters of integrative conjugative elements (ICE) are found in a high number of Xanthomonas PAIs: integrase-like sequences and type IV secretion systems (T4SS) genes. Since ICEs may also originate from genomic islands, the high quantity of these types of sequence may indicate Xanthomonas might have acquired genomic islands through ICE events, and the well-conserved ones among strains are those containing mobile elements encoded by ICE [44]. Furthermore, as PAIs evolve to carry only the genes essential for their maintenance and transference [45], considering the PAIs here identified lack the usual genetic features commonly associated with pathogenicity (such as virulence factors, toxins, adhesins, and others), perhaps the genomic islands of Xanthomonas might have already gone through strong evolutionary pressure. As seen in Figure S7, a few putative virulence factors changed their genomic syntenic region when transference occurred, which may indicate genome shuffling. Although component genes of T4SS were not directly associated with virulence in different Xanthomonas species, the presence of T4SS genes in PAIs is essential because it may aid in interspecific competition whenever contact between different plant microbiome bacteria happens, thus, facilitating host colonization [42,46]. Our results present significant ontological terms of biological, molecular, and cellular processes implicated in pathogenicity and bacterial virulence. Considering biological process features analysis, a considerable number of GO terms classified as DNA-mediated transposition was found in genomes of X. citri. The recombinant DNA-mediated gene can produce xanthan gum, which is essential for colonization and bacterial growth [47,48], promoting infection success. In molecular mechanisms, genes encoding type III effectors play a crucial role in plant–pathogen interaction, stimulating defense responses [49,50]. Sequences related to the nucleic acid-binding ontology, present in most PAIs, have already been described in X. campestris [51]. Those proteins may act as catabolic factors and are involved in phytopathogenesis regulation; however, it is important to note that not only nucleic acid-binding proteins are responsible for gene regulation [52]. Activities related to the growth and proliferation of bacteria within the host are also associated with the presence of iron-sulfur binding proteins, essential for micronutrient acquisition required for pathogenic bacteria [53,54,55]. They play critical roles in the control of many cellular activities essential to pathogenicity, such as metabolic pathways and intracellular transport molecules [56]. Genomic evolution studies of X. campestris pv. campestris and X. citri pv. citri identified 30 genomic islands that originated from the lateral transference of genes [57]. This suggests that it could be associated with the improved ability of a pathogen to adapt to specific environments and/or hosts. In our study, homologous genes for resistance were found on the pathogenicity islands as well. Metallopeptidases, for instance, are typically associated with catalytic activities such as the cleavage of reactive oxygen species (ROS) in dismutation reactions [58]. The burst of ROS has an antimicrobial effect on the plant cell, so those genes are associated with defense within the host [59]. It demonstrates how genes located in PAIs do not strictly act as virulence factors but may also aid in the pathogen protection against natural defenses on host.
Finally, this work is the first study to carry out an in-depth comparative analysis of Xanthomonas species presenting ontological characterization and excellent curation of genes and their predicted products in these complete genomes. The pathogenicity island analysis revealed an essential role in the infection process and a wide field for experimental investigation in pathways acting directly on plant–pathogen response. Due to the environmental microbial diversity, this community undergoes selective pressures over the years, making it difficult to understand the association of a pathovar/disease to a particular genomic repertoire. More studies aimed at the microbial community can open a potential spectrum on this subject. Due to the high similarity among PAIs belonging to X. citri pv. anacardii, X. citri pv. glycines and X. citri pv. fuscans strains, we propose that those pathovars might have similar virulence mechanisms. Therefore, the same methods for diagnostic and preventive treatment might also be considered for the affected crops. The response mechanism that those different hosts display to stop these pathogens also needs to be considered.

4.3. Prophage Regions and the Evolution of Bacterial Phytopathogens

Many studies have tried to infer the origin and role of prophage regions in bacteria to elucidate a disease or the ability to interact with the host; nevertheless, the mechanisms still seem unknown [60,61]. Plant–pathogen interactions allow a high genetic variation and exchange both between the environment and between the host, so the higher is the host range of a pathogen, the higher genetic variability it displays. Transposable element insertion may alter the frame of determining genes, reducing or increasing their expression level and, therefore, affecting bacterial virulence. The presence of many genetic elements in these genomes reinforces the occurrence of past recombination or horizontal transfer events [8].
Prophage regions have already been reported for X. campestris pv. campestris ATCC 33913, attributed to insertion events before the evolution and separation events among X. campestris and Xanthomonas oryzae species, with identity superior to 90% [60]. Since we observed overlapping regions with PAIs and prophage sequences, it suggests that phage insertions occurred in one original strain and disseminated through genomic island sharing events. Most strains of the same pathovar were obtained in the same geographical region, reinforcing that they probably shared those genomic regions before the diversification of those species.

5. Conclusions

Overall, the participation of pathogenicity islands in the Xanthomonas genus’ accessory genome is undeniable since most islands were specific in each lineage subgroup, despite the overall great genomic similarity. Up until now, a significant part of Xanthomonas’ molecular features is still unknown, and as they are also present in PAIs, they may contain vital information for understanding its virulence. On this thought, future studies are fundamental to help understand pathogen-host relationships better, and that knowledge would also influence the development of preventive biotechnological tools in modern agriculture, especially for plant immunization. A broad accessory pan-genome influencing pathogenicity means developing specific strategies to fight each pathovar on their own, but a soon-to-be-closed pan-genome means those strategies might be effective for a considerable time. In addition to that, the characterization of the different PAIs investigated in this study suggests that some may be indirectly involved in virulence, as many of them contain transposable elements that can alter the actual genomic configuration and control of gene expression originating from past phages. Finally, Xanthomonas bacteria are highly adapted to phytopathogenicity due to their big genetic arsenal.

Supplementary Materials

The following supporting information can be downloaded at: https://www.mdpi.com/article/10.3390/bacteria1040017/s1.

Author Contributions

Conceptualization, supervision, writing—review and editing: F.F.A. and A.M.B.-I.; methodology, formal analysis, and data curation: J.C.A. and D.L.N.R.; writing—original draft preparation: J.C.A.; writing—review and editing: S.d.C.S. and V.A. All authors have read and agreed to the published version of the manuscript.

Funding

This research received no external funding.

Institutional Review Board Statement

Not applicable.

Informed Consent Statement

Not applicable.

Data Availability Statement

All genomes are available in the NCBI database.

Acknowledgments

We would like to thank the agencies Coordination for the Improvement of Higher Education Personnel (CAPES), Minas Gerais Research Funding Foundation (FAPEMIG) for the Post-Graduate Support Program (PAPG) scholarship ID-11713 5.18/2022, and Pernambuco Research Funding Foundation (FACEPE) for Institutional Scientific Initiation Scholarship Program (PIBIC) BIC-2027-22/17. We would also like to thank the Post Graduate Program in Bioinformatics at the Federal University of Minas Gerais.

Conflicts of Interest

The authors declare no conflict of interest.

Appendix A. General Information Regarding Genomes Used in This Work

All information was retrieved from NCBI, both for Xanthomonas campestris and Xanthomonas citri.
Table A1. Relevant information for the X. campestris and X. citri strains.
Table A1. Relevant information for the X. campestris and X. citri strains.
Species [18]StrainsBioProjectRepliconsAssemblyPhytobacteriosis
Xanthomonas arboricola (Vauterin et al. 1995)17PRJNA280784CP011256.1GCA_000972745.1Black rot of crucifers
Xanthomonas campestris pv. campestris (Pammel) Dowson3811PRJNA428847NZ_CP025750.1GCA_002879955.1Black rot of crucifers
B100PRJNA29801NC_010688.1GCA_000070605.1
ICMP 21080PRJNA283327NZ_CP012145.1GCA_001186415.1
ICMP 4013PRJNA283326NZ_CP012146.1GCA_001186465.1
8004PRJNA15NC_007086.1GCA_000012105.1
CN03PRJNA211759NZ_CP017308.1GCA_002776735.1
CN18PRJNA343742NZ_CP017319.1GCA_002776835.1
ATCC 33913PRJNA296NC_003902GCA_000007145.1
CN12PRJEB4853NZ_CP017310.1GCA_002776775.1
CN17PRJNA211780CP017307.1GCA_002776715.1
Xanthomonas campestris pv. raphani (White) Dye756CPRJNA63187NC_017271.1GCA_000221965.1Black rot of crucifers
Xanthomonas citri pv. anacardii (Ah-You et al. 2009) [62]IBSBF2579PRJNA224116NZ_PESI01000001.1GCA_002837255.1Bacterial black spot
TAQ13PRJNA224116NZ_PESH01000000GCA_002898475.1
TAQ18PRJNA224116NZ_PESG01000001.1GCA_002898415.1
Xanthomonas citri pv. aurantifolii (Ah-You et al. 2009)1566PRJNA273983NZ_CP012002.1GCA_001610915.1Citrus canker
FDC 1559PRJNA273983NZ_CP011160.1GCA_001610795.1
FDC 1561PRJNA273983NZ_CP011250.1GCA_002079965.1
FDC 1609PRJNA273983NZ_CP011163.1GCA_001610815.1
Xanthomonas citri pv. fuscans (Schaad et al. 2007)ISO12C3PRJNA289080NZ_CP012055.1GCA_003999505.1Bacterial blight of bean
ISO18C1PRJNA289080NZ_CP012053.1GCA_003999485.1
ISO18C5PRJNA289080NZ_CP012051.1GCA_004000475.1
4834-RPRJNA176873NC_022539.1GCA_000969685.1
Xanthomonas citri pv. glycines (Nakano, 2019)12-2PRJNA323439NZ_CP015972.1GCA_002163775.1  Bacterial pustule of soybean
8raPRJNA341902NZ_CP017188.1GCA_001854145.2
Xanthomonas citri pv. phaseoli var. fuscans (ex Smith, 1987) Dye 1978         CFBP4885PRJNA384182NZ_CP020992.1GCA_002759355.2Bacterial blight of bean
CFBP6165PRJNA384145NZ_CP020998.1GCA_002759215.3
CFBP6166PRJNA384183NZ_CP021001.1GCA_002759235.2
CFBP6167PRJNA384187NZ_CP021018.1GCA_002759415.2
CFBP6975PRJNA384188NZ_CP021006.1GCA_002759255.3
CFBP6988RPRJNA384160NZ_CP020979.1GCA_002759275.2
CFBP6989PRJNA384161NZ_CP020981.1GCA_002759295.2
CFBP6990PRJNA384163NZ_CP020983.1GCA_002759315.2
CFBP6991PRJNA384178NZ_CP021015.1GCA_002759395.2
CFBP6992PRJNA384177NZ_CP020985.1GCA_002759335.2
CFBP6994RPRJNA384179NZ_CP020987.1GCA_002759175.2
CFBP6996RPRJNA384180NZ_CP020989.1GCA_002759195.2
CFBP7767PRJNA383319NZ_CP021012.1GCA_002759375.2
Xanthomonas citri pv. vignicola (Burkholder, 1994)CFBP7111PRJNA390891NZ_CP022263.1GCA_002218245.1     Bacterial blight of cowpea
CFBP7112PRJNA390892NZ_CP022267.1GCA_002218265.1
CFBP7113PRJNA390890NZ_CP022270.1GCA_002218285.1
Xanthomonas citri subsp. citri (Gabriel et al. 1989) Schaad et al. 2007          03-1638-1-1PRJNA401937     NZ_CP023285.1     GCA_002952295.1Citrus canker
Xcc29-1PRJNA407058NZ_CP023661.1GCA_003665475.1
Xcc49PRJNA407058NZ_CP023662.1GCA_003665455.1
MSCTPRJNA299817NZ_CP017020.1GCA_001719145.1
5208PRJNA255042NZ_CP009026.1GCA_000961415.1
AW13PRJNA255042NZ_CP009029.1GCA_000961435.1
AW14PRJNA255042NZ_CP009032.1GCA_000961455.1
AW15PRJNA255042NZ_CP009035.1GCA_000961475.1
AW16PRJNA255042NZ_CP009038.1GCA_000961495.1
BL18PRJNA255042NZ_CP009023.1GCA_000961395.1
FB19PRJNA255042NZ_CP009020.1GCA_000961375.1
gd2PRJNA255042NZ_CP009017.1GCA_000961355.1
gd3PRJNA255042NZ_CP009014.1GCA_000961335.1
jx-6PRJNA286060NZ_CP011827.1GCA_001028285.3
jx4PRJNA255042NZ_CP009011.1GCA_000961315.1
jx5PRJNA255042NZ_CP009008.1GCA_000961295.1
LH201PRJNA344031NZ_CP018858.1GCA_001922105.1
LH276PRJNA344031NZ_CP018854.1GCA_001922065.1
LJ207-7PRJNA344031NZ_CP018850.1GCA_001922085.1
LL074-4PRJNA344031NZ_CP018847.1GCA_001922045.1
mf20PRJNA255042NZ_CP009005.1GCA_000961275.1
MN10PRJNA255042NZ_CP009002.1GCA_000961255.1
MN11PRJNA255042NZ_CP008999.1GCA_000961235.1
MN12PRJNA255042NZ_CP008996.1GCA_000961215.1
NT17PRJNA255042NZ_CP008993.1GCA_000961195.1
TX160042PRJNA381640NZ_CP020882.1GCA_002139975.1
TX160149PRJNA381640NZ_CP020885.1GCA_002139955.1
TX160197PRJNA381640NZ_CP020889.1GCA_002139995.1
UI7PRJNA255042NZ_CP008987.1GCA_000961155.1
306PRJNA297NC_003919.1GCA_000007165.1
UI6PRJNA255042NZ_CP008990.1GCA_000961175.1
A306PRJNA193618NZ_CP006855.1GCA_000816885.1
Aw12879PRJNA81931NC_020815.GCA_000349225.1
Xanthomonas citri subsp. malvacearum (ex Smith 1901) Schaad et al. 2007MS14003PRJNA396899NZ_CP023159.1GCA_002288585.1Bacterial blight of cotton
AR81009PRJNA396899NZ_CP023155.1GCA_002288565.1
XcmH1005PRJNA298765NZ_CP013004.1GCA_002224525.1
XcmN1003PRJNA298770NZ_CP013006.1GCA_002224545.1
Xanthomonas vasicola pv. arecae (Rao & Mohan) Dye 1978NCPPB 2649PRJNA264725CP034653.1GCA_000770355.2Bacterial leaf streak of maize
Xanthomonas vasicola pv. musacearum (Yirgou & Bradbury) Dye 1978NCPPB 4379PRJNA73877     NZ_CP034655.1    GCA_000277895.2Xanthomonas wilt of banana

Appendix B. Mobile Elements Found within Xanthomonas Genomes

Table A2. Number of Pathogenicity Islands (PAIs) found for each genome.
Table A2. Number of Pathogenicity Islands (PAIs) found for each genome.
Species [18]StrainsNumber of PAIs
Xanthomonas arboricola173
Xanthomonas campestris pv. campestris800410
CN036
CN128
CN177
CN187
38119
ATCC 3391310
B1007
ICMP 210808
ICMP 40137
Xanthomonas campestris pv. raphani756C4
Xanthomonas citri pv. anacardiiIBSBF25798
TAQ137
TAQ187
Xanthomonas citri pv. aurantifolii15667
FDC155911
FDC15616
FDC16098
Xanthomonas citri pv. fuscansISO118C14
ISO118C53
ISO12C33
4834-R4
Xanthomonas citri pv. glycines12-27
8ra6
Xanthomonas citri pv. phaseoli var. fuscansCFBP48857
CFBP61654
CFBP61664
CFBP61673
CFBP69754
CFBP6988R3
CFBP69894
CFBP69904
CFBP69913
CFBP69923
CFBP6994R5
CFBP6996R4
CFBP77677
Xanthomonas citri pv. vignicolaCFBP711110
CFBP71128
CFBP71137
Xanthomonas citri subsp. citri (Gabriel et al. 1989) Schaad et al. 20073068
03-1638-1-19
52088
A3069
Aw1287912
AW1313
AW1414
AW1511
AW1613
BL189
FB199
gd27
gd37
jx-69
jx48
jx59
LH2019
LH2769
LJ207-78
LL074-48
mf209
MN109
MN119
MN129
NT178
TX16004213
TX16014910
TX16019714
UI67
UI77
Xcc29-19
Xcc498
Xanthomonas citri subsp. malvacearum (ex Smith 1901) Schaad et al. 2007AR8100915
MS140034
MSCT5
XcmH100513
XcmN100310
Xanthomonas vasicola pv. arecaeNCPPB26498
Xanthomonas vasicola pv. musacearumNCPPB 43796
Table A3. Number of prophages regions in Xanthomonas genomes.
Table A3. Number of prophages regions in Xanthomonas genomes.
StrainsIntact RegionQuestionable RegionIncomplete RegionTotal Prophage Regions
Xanthomonas arboricola 174004
Xanthomonas campestrispv. campestris CN171102
Xanthomonas campestris pv. campestris 38110101
Xanthomonas campestris pv. campestris 80042002
Xanthomonas campestris pv. campestris ATCC 339132103
Xanthomonas campestris pv. campestris B1001001
Xanthomonas campestris pv. campestris CN031203
Xanthomonas campestris pv. campestris CN120303
Xanthomonas campestris pv. campestris CN180000
Xanthomonas campestris pv. campestris ICMP 210802103
Xanthomonas campestris pv. campestris ICMP 40130101
Xanthomonas campestris pv. raphani 756C0101
Xanthomonas citri pv. anacardii IBSBF25791012
Xanthomonas citri pv. anacardii TAQ131012
Xanthomonas citri pv. anacardii TAQ181012
Xanthomonas citri pv. aurantifolii 15662338
Xanthomonas citri pv. aurantifolii FDC15592237
Xanthomonas citri pv. aurantifolii FDC15611102
Xanthomonas citri pv. aurantifolii FDC160932712
Xanthomonas citri pv. fuscans 4834-R1001
Xanthomonas citri pv. fuscans ISO118C11001
Xanthomonas citri pv. fuscans ISO118C51001
Xanthomonas citri pv. fuscans ISO12C31001
Xanthomonas citri pv. glycines 12-23115
Xanthomonas citri pv. glycines 8ra4105
Xanthomonas citri pv. phaseoli var. fuscans CFBP48851001
Xanthomonas citri pv. phaseoli var. fuscans CFBP61651001
Xanthomonas citri pv. phaseoli var. fuscans CFBP61661001
Xanthomonas citri pv. phaseoli var. fuscans CFBP61671001
Xanthomonas citri pv. phaseoli var. fuscans CFBP69752002
Xanthomonas citri pv. phaseoli var. fuscans CFBP6988R2013
Xanthomonas citri pv. phaseoli var. fuscans CFBP69892013
Xanthomonas citri pv. phaseoli var. fuscans CFBP69902013
Xanthomonas citri pv. phaseoli var. fuscans CFBP69912013
Xanthomonas citri pv. phaseoli var. fuscans CFBP69921001
Xanthomonas citri pv. phaseoli var. fuscans CFBP6994R2002
Xanthomonas citri pv. phaseoli var. fuscans CFBP6996R1001
Xanthomonas citri pv. phaseoli var. fuscans CFBP77671001
Xanthomonas citri pv. vignicola CFBP71114048
Xanthomonas citri pv. vignicola CFBP71121102
Xanthomonas citri pv. vignicola CFBP71132136
Xanthomonas citri subsp. citri 03-1638-1-11214
Xanthomonas citri subsp. citri 52081124
Xanthomonas citri subsp. citri A3061124
Xanthomonas citri subsp. citri Aw128793126
Xanthomonas citri subsp. citri AW133126
Xanthomonas citri subsp. citri AW143126
Xanthomonas citri subsp. citri AW153126
Xanthomonas citri subsp. citri AW163126
Xanthomonas citri subsp. citri BL181124
Xanthomonas citri subsp. citri FB191124
Xanthomonas citri subsp. citri gd21124
Xanthomonas citri subsp. citri gd31124
Xanthomonas citri subsp. citri jx-61113
Xanthomonas citri subsp. citri jx41124
Xanthomonas citri subsp. citri jx51124
Xanthomonas citri subsp. citri LH2011113
Xanthomonas citri subsp. citri LH2761214
Xanthomonas citri subsp. citri LJ207-71214
Xanthomonas citri subsp. citri LL074-41214
Xanthomonas citri subsp. citri mf201124
Xanthomonas citri subsp. citri MN101124
Xanthomonas citri subsp. citri MN111124
Xanthomonas citri subsp. citri MN121124
Xanthomonas citri subsp. citri NT171124
Xanthomonas citri subsp. citri str. 3060000
Xanthomonas citri subsp. citri TX1600423104
Xanthomonas citri subsp. citri TX1601492136
Xanthomonas citri subsp. citri TX1601973104
Xanthomonas citri subsp. citri UI61124
Xanthomonas citri subsp. citri UI71124
Xanthomonas citri subsp. citri Xcc29-11113
Xanthomonas citri subsp. citri Xcc491113
Xanthomonas citri subsp. malvacearum AR810090000
Xanthomonas citri subsp. malvacearum MS140032013
Xanthomonas citri subsp. malvacearum MSCT1001
Xanthomonas citri subsp. malvacearum XcmH10050202
Xanthomonas citri subsp. malvacearum XcmN10033115
Xanthomonas vasicola pv. arecae NCPPB26491203
Xanthomonas vasicola pv. musacearum NCPPB 4379     2013

References

  1. Chagas, M.C.M.; Parra, J.R.P.; Namekata, T.; Hartung, J.S.; Yamamoto, P.T. Phyllocnistis citrella Stainton (Lepidoptera: Gracillariidae) and its relationship with the citrus canker bacterium Xanthomonas axonopodis pv citri in Brazil. Neotrop. Entomol. 2001, 30, 55–59. [Google Scholar] [CrossRef]
  2. Nascimento, A.R.P.; Mariano, R.d.L.R. Cancro bacteriano da videira: Etiologia, epidemiologia e medidas de controle. Cienc. Rural 2004, 34, 301–307. [Google Scholar] [CrossRef]
  3. Iglesias-Bernabé, L.; Madloo, P.; Rodríguez, V.M.; Francisco, M.; Soengas, P. Dissecting quantitative resistance to Xanthomonas campestris pv. campestris in leaves of Brassica oleracea by QTL analysis. Sci. Rep. 2019, 9, 2015. [Google Scholar] [CrossRef] [PubMed]
  4. Batista, J.N.G.; Ferreira, M.A.d.S.V.; Quezado-Duval, A.M. Molecular and phenotypic characterization of Xanthomonas campestris pv. campestris causing black rot in Brassica crops in Brazil. Trop. Plant Pathol. 2021, 46, 684–701. [Google Scholar] [CrossRef]
  5. Nuñez, A.M.P.; Rodríguez, G.A.A.; Monteiro, F.P.; Faria, A.F.; Silva, J.C.P.; Monteiro, A.C.A.; Carvalho, C.V.; Gomes, L.A.A.; Souza, R.M.; de Souza, J.T.; et al. Bio-based products control black rot (Xanthomonas campestris pv. campestris) and increase the nutraceutical and antioxidant components in kale. Sci. Rep. 2018, 8, 10199. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  6. Behlau, F. An overview of citrus canker in Brazil. Trop. Plant Pathol. 2021, 46, 1–12. [Google Scholar] [CrossRef]
  7. Ference, C.M.; Gochez, A.M.; Behlau, F.; Wang, N.; Graham, J.H.; Jones, J.B. Recent advances in the understanding of Xanthomonas citri ssp. citri pathogenesis and citrus canker disease management. Mol. Plant Pathol. 2018, 19, 1302–1318. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  8. Lu, H.; Patil, P.; Van Sluys, M.A.; White, F.F.; Ryan, R.P.; Dow, J.M.; Rabinowicz, P.; Salzberg, S.L.; Leach, J.E.; Sonti, R.; et al. Acquisition and Evolution of Plant Pathogenesis–Associated Gene Clusters and Candidate Determinants of Tissue-Specificity in Xanthomonas. PLoS ONE 2008, 3, e3828. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  9. Hersemann, L.; Wibberg, D.; Blom, J.; Goesmann, A.; Widmer, F.; Vorhölter, F.J.; Kölliker, R. Comparative genomics of host adaptive traits in Xanthomonas translucens pv. graminis. BMC Genom. 2017, 18, 35. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  10. Jacques, M.A.; Arlat, M.; Boulanger, A.; Boureau, T.; Carrère, S.; Cesbron, S.; Chen, N.W.; Cociancich, S.; Darrasse, A.; Denancé, N.; et al. Using Ecology, Physiology, and Genomics to Understand Host Specificity in Xanthomonas. Annu. Rev. Phytopathol. 2016, 54, 163–187. [Google Scholar] [CrossRef] [PubMed]
  11. Assis, R.A.B.; Varani, A.M.; Sagawa, C.H.D.; Patané, J.S.L.; Setubal, J.C.; Uceda-Campos, G.; da Silva, A.M.; Zaini, P.A.; Almeida, N.F.; Moreira, L.M.; et al. A comparative genomic analysis of Xanthomonas arboricola pv. juglandis strains reveal hallmarks of mobile genetic elements in the adaptation and accelerated evolution of virulence. Genomics 2021, 113, 2513–2525. [Google Scholar] [CrossRef] [PubMed]
  12. Huang, C.J.; Wu, T.L.; Zheng, P.X.; Ou, J.Y.; Ni, H.F.; Lin, Y.C. Comparative Genomic Analysis Uncovered Evolution of Pathogenicity Factors, Horizontal Gene Transfer Events, and Heavy Metal Resistance Traits in Citrus Canker Bacterium Xanthomonas citri subsp. citri. Front. Microbiol. 2021, 12, 731711. [Google Scholar] [CrossRef] [PubMed]
  13. Loper, J.E.; Hassan, K.A.; Mavrodi, D.V.; Davis, E.W.; Lim, C.K.; Shaffer, B.T.; Elbourne, L.D.H.; Stockwell, V.O.; Hartney, S.L.; Breakwell, K.; et al. Comparative Genomics of Plant-Associated Pseudomonas spp.: Insights into Diversity and Inheritance of Traits Involved in Multitrophic Interactions. PLoS Genet. 2012, 8, e1002784. [Google Scholar] [CrossRef] [Green Version]
  14. Hajri, A.; Brin, C.; Hunault, G.; Lardeux, F.; Lemaire, C.; Manceau, C.; Boureau, T.; Poussier, S. A «repertoire for repertoire» hypothesis: Repertoires of type three effectors are candidate determinants of host specificity in Xanthomonas. PLoS ONE 2009, 4, e6632. [Google Scholar] [CrossRef]
  15. Kay, S.; Bonas, U. How Xanthomonas type III effectors manipulate the host plant. Curr. Opin. Microbiol. 2009, 12, 37–43. [Google Scholar] [CrossRef] [PubMed]
  16. Timilsina, S.; Pereira-Martin, J.A.; Minsavage, G.V.; Iruegas-Bocardo, F.; Abrahamian, P.; Potnis, N.; Kolaczkowski, B.; Vallad, G.E.; Goss, E.M.; Jones, J.B. Multiple Recombination Events Drive the Current Genetic Structure of Xanthomonas perforans in Florida. Front. Microbiol. 2019, 10, 448. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  17. da Gama, M.A.S.; Mariano, R.d.L.R.; da Silva Júnior, W.J.; de Farias, A.R.G.; Barbosa, M.A.G.; Ferreira, M.Á.d.S.V.; Costa Júnior, C.R.L.; Santos, L.A.; de Souza, E.B. Taxonomic Repositioning of Xanthomonas campestris pv. viticola (Nayudu 1972) Dye 1978 as Xanthomonas citri pv. viticola (Nayudu 1972) Dye 1978 comb. nov. and Emendation of the Description of Xanthomonas citri pv. anacardii to Include Pigmented Isolates Pathogenic to Cashew Plant. Phytopathology 2018, 108, 1143–1153. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  18. Constantin, E.C.; Cleenwerck, I.; Maes, M.; Baeyen, S.; Van Malderghem, C.; De Vos, P.; Cottyn, B. Genetic characterization of strains named as Xanthomonas axonopodis pv. dieffenbachiae leads to a taxonomic revision of the X. axonopodis species complex. Plant Pathol. 2016, 65, 792–806. [Google Scholar] [CrossRef]
  19. Cesbron, S.; Briand, M.; Essakhi, S.; Gironde, S.; Boureau, T.; Manceau, C.; Fischer-Le Saux, M.; Jacques, M.A. Comparative Genomics of Pathogenic and Nonpathogenic Strains of Xanthomonas arboricola Unveil Molecular and Evolutionary Events Linked to Pathoadaptation. Front. Plant Sci. 2015, 6, 1126. [Google Scholar] [CrossRef] [PubMed]
  20. Studholme, D.J.; Wicker, E.; Abrare, S.M.; Aspin, A.; Bogdanove, A.; Broders, K.; Dubrow, Z.; Grant, M.; Jones, J.B.; Karamura, G.; et al. Transfer of Xanthomonas campestris pv. arecae and X. campestris pv. musacearum to X. vasicola (Vauterin) as X. vasicola pv. arecae comb. nov. and X. vasicola pv. musacearum comb. nov. and Description of X. vasicola pv. vasculorum pv. nov. Phytopathology 2020, 110, 1153–1160. [Google Scholar] [CrossRef] [Green Version]
  21. Aziz, R.K.; Bartels, D.; Best, A.A.; DeJongh, M.; Disz, T.; Edwards, R.A.; Formsma, K.; Gerdes, S.; Glass, E.M.; Kubal, M.; et al. The RAST Server: Rapid Annotations using Subsystems Technology. BMC Genom. 2008, 9, 75. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  22. Carver, T.; Berriman, M.; Tivey, A.; Patel, C.; Böhme, U.; Barrell, B.G.; Parkhill, J.; Rajandream, M.A. Artemis and ACT: Viewing, annotating and comparing sequences stored in a relational database. Bioinformatics 2008, 24, 2672–2676. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  23. Araujo, F.A.; Barh, D.; Silva, A.; Guimarães, L.; Ramos, R.T.J. GO FEAT: A rapid web-based functional annotation tool for genomic and transcriptomic data. Sci. Rep. 2018, 8, 1794. [Google Scholar] [CrossRef] [Green Version]
  24. Kanehisa, M. The KEGG resource for deciphering the genome. Nucleic Acids Res. 2004, 32, D277-80. [Google Scholar] [CrossRef] [Green Version]
  25. Chaudhari, N.M.; Gupta, V.K.; Dutta, C. BPGA—An ultra-fast pan-genome analysis pipeline. Sci. Rep. 2016, 6, 24373. [Google Scholar] [CrossRef] [Green Version]
  26. Page, A.J.; Cummins, C.A.; Hunt, M.; Wong, V.K.; Reuter, S.; Holden, M.T.; Fookes, M.; Falush, D.; Keane, J.A.; Parkhill, J. Roary: Rapid large-scale prokaryote pan genome analysis. Bioinformatics 2015, 31, 3691–3693. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  27. Rambaut, A. FigTree—Version 1.4. 3, a Graphical Viewer of Phylogenetic Trees. 2017. Computer program distributed by the author. Available online: http://tree.bio.ed.ac.uk/software/figtree (accessed on 10 September 2022).
  28. Chen, L.; Yang, J.; Yu, J.; Yao, Z.; Sun, L.; Shen, Y.; Jin, Q. VFDB: A reference database for bacterial virulence factors. Nucleic Acids Res. 2005, 33, D325–D328. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  29. Soares, S.C.; Geyik, H.; Ramos, R.T.J.; de Sá, P.H.C.G.; Barbosa, E.G.V.; Baumbach, J.; Figueiredo, H.C.P.; Miyoshi, A.; Tauch, A.; Silva, A.; et al. GIPSy: Genomic island prediction software. J. Biotechnol. 2016, 232, 2–11. [Google Scholar] [CrossRef] [PubMed]
  30. Bertelli, C.; Brinkman, F.S.L. Improved genomic island predictions with IslandPath-DIMOB. Bioinformatics 2018, 34, 2161–2167. [Google Scholar] [CrossRef] [PubMed]
  31. Alikhan, N.F.; Petty, N.K.; Ben Zakour, N.L.; Beatson, S.A. BLAST Ring Image Generator (BRIG): Simple prokaryote genome comparisons. BMC Genom. 2011, 12, 402. [Google Scholar] [CrossRef]
  32. Darling, A.C.E.; Mau, B.; Blattner, F.R.; Perna, N.T. Mauve: Multiple alignment of conserved genomic sequence with rearrangements. Genome Res. 2004, 14, 1394–1403. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  33. Yu, N.Y.; Wagner, J.R.; Laird, M.R.; Melli, G.; Rey, S.; Lo, R.; Dao, P.; Sahinalp, S.C.; Ester, M.; Foster, L.J.; et al. PSORTb 3.0: Improved protein subcellular localization prediction with refined localization subcategories and predictive capabilities for all prokaryotes. Bioinformatics 2010, 26, 1608–1615. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  34. Arndt, D.; Grant, J.R.; Marcu, A.; Sajed, T.; Pon, A.; Liang, Y.; Wishart, D.S. PHASTER: A better, faster version of the PHAST phage search tool. Nucleic Acids Res. 2016, 44, W16–W21. [Google Scholar] [CrossRef] [Green Version]
  35. Singh, A.; Bansal, K.; Kumar, S.; Patil, P.B. Deep Population Genomics Reveals Systematic and Parallel Evolution at a Lipopolysaccharide Biosynthetic Locus in Xanthomonas Pathogens That Infect Rice and Sugarcane. Appl. Environ. Microbiol. 2022, 88, e00550-22. [Google Scholar] [CrossRef]
  36. Zarei, S.; Taghavi, S.M.; Rahimi, T.; Mafakheri, H.; Potnis, N.; Koebnik, R.; Fischer-Le Saux, M.; Pothier, J.F.; Palacio Bielsa, A.; Cubero, J.; et al. Taxonomic Refinement of Xanthomonas arboricola. Phytopathology 2022, 112, 1630–1639. [Google Scholar] [CrossRef] [PubMed]
  37. Rana, R.; Madhavan, V.N.; Saroha, T.; Bansal, K.; Kaur, A.; Sonti, R.V.; Patel, H.K.; Patil, P.B. Xanthomonas indica sp. nov., a Novel Member of Non-Pathogenic Xanthomonas Community from Healthy Rice Seeds. Curr. Microbiol. 2022, 79, 304. [Google Scholar] [CrossRef] [PubMed]
  38. Cho, H.; Song, E.S.; Heu, S.; Baek, J.; Lee, Y.K.; Lee, S.; Lee, S.W.; Park, D.S.; Lee, T.H.; Kim, J.G.; et al. Prediction of Host-Specific Genes by Pan-Genome Analyses of the Korean Ralstonia solanacearum Species Complex. Front. Microbiol. 2019, 10, 506. [Google Scholar] [CrossRef] [Green Version]
  39. Kang, I.J.; Kim, K.S.; Beattie, G.A.; Yang, J.W.; Sohn, K.H.; Heu, S.; Hwang, I. Pan-Genome Analysis of Effectors in Korean Strains of the Soybean Pathogen Xanthomonas citri pv. glycines. Microorganisms 2021, 9, 2065. [Google Scholar] [CrossRef]
  40. Patil, P.P.; Midha, S.; Kumar, S.; Patil, P.B. Genome Sequence of Type Strains of Genus Stenotrophomonas. Front. Microbiol. 2016, 7, 309. [Google Scholar] [CrossRef] [Green Version]
  41. Thieme, F.; Koebnik, R.; Bekel, T.; Berger, C.; Boch, J.; Büttner, D.; Caldana, C.; Gaigalat, L.; Goesmann, A.; Kay, S.; et al. Insights into Genome Plasticity and Pathogenicity of the Plant Pathogenic Bacterium Xanthomonas campestris pv. vesicatoria Revealed by the Complete Genome Sequence. J. Bacteriol. 2005, 187, 7254–7266. [Google Scholar] [CrossRef]
  42. Souza, D.P.; Oka, G.U.; Alvarez-Martinez, C.E.; Bisson-Filho, A.W.; Dunger, G.; Hobeika, L.; Cavalcante, N.S.; Alegria, M.C.; Barbosa, L.R.; Salinas, R.K.; et al. Bacterial killing via a type IV secretion system. Nat. Commun. 2015, 6, 6453. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  43. Bansal, K.; Midha, S.; Kumar, S.; Patil, P.B. Ecological and Evolutionary Insights into Xanthomonas citri Pathovar Diversity. Appl. Environ. Microbiol. 2017, 83, e02993-16. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  44. Johnson, C.M.; Grossman, A.D. Integrative and Conjugative Elements (ICEs): What They Do and How They Work. Annu. Rev. Genet. 2015, 49, 577–601. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  45. Hallstrom, K.N.; McCormick, B.A. Pathogenicity Islands. In Molecular Medical Microbiology; Elsevier: Amsterdam, The Netherlands, 2015; pp. 303–314. [Google Scholar] [CrossRef]
  46. Sgro, G.G.; Oka, G.U.; Souza, D.P.; Cenens, W.; Bayer-Santos, E.; Matsuyama, B.Y.; Bueno, N.F.; dos Santos, T.R.; Alvarez-Martinez, C.E.; Salinas, R.K.; et al. Bacteria-Killing Type IV Secretion Systems. Front. Microbiol. 2019, 10, 1078. [Google Scholar] [CrossRef] [PubMed]
  47. Katzen, F.; Ferreiro, D.U.; Oddo, C.G.; Ielmini, M.V.; Becker, A.; Pühler, A.; Ielpi, L. Xanthomonas campestris pv. campestris gum Mutants: Effects on Xanthan Biosynthesis and Plant Virulence. J. Bacteriol. 1998, 180, 1607–1617. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  48. Capage, M.; Doherty, D.H.; Betlach, M.; Vanderslice, R.W. Recombinant-DNA mediated production of xanthan gum. Biotechnology Advances 1997, 15, 547. [Google Scholar]
  49. Büttner, D.; Noël, L.; Thieme, F.; Bonas, U. Genomic approaches in Xanthomonas campestris pv. vesicatoria allow fishing for virulence genes. J. Biotechnol. 2003, 106, 203–214. [Google Scholar] [CrossRef]
  50. Han, S.W.; Hwang, B.K. Molecular functions of Xanthomonas type III effector AvrBsT and its plant interactors in cell death and defense signaling. Planta 2017, 245, 237–253. [Google Scholar] [CrossRef]
  51. Dong, Q.; Ebright, R.H. DNA binding specificity and sequence of Xanthomonas campestris catabolite gene activator protein-like protein. J. Bacteriol. 1992, 174, 5457–5461. [Google Scholar] [CrossRef] [Green Version]
  52. de Crecy-Lagard, V.; Glaser, P.; Lejeune, P.; Sismeiro, O.; Barber, C.E.; Daniels, M.J.; Danchin, A. A Xanthomonas campestris pv. campestris protein similar to catabolite activation factor is involved in regulation of phytopathogenicity. J. Bacteriol. 1990, 172, 5877–5883. [Google Scholar] [CrossRef]
  53. Payne, S.M. Iron acquisition in microbial pathogenesis. Trends Microbiol. 1993, 1, 66–69. [Google Scholar] [CrossRef]
  54. Jordan, M.R.; Wang, J.; Capdevila, D.A.; Giedroc, D.P. Multi-metal nutrient restriction and crosstalk in metallostasis systems in microbial pathogens. Curr. Opin. Microbiol. 2020, 55, 17–25. [Google Scholar] [CrossRef] [PubMed]
  55. Zhang, P.; Jiang, D.; Wang, Y.; Yao, X.; Luo, Y.; Yang, Z. Comparison of De Novo Assembly Strategies for Bacterial Genomes. Int. J. Mol. Sci. 2021, 22, 7668. [Google Scholar] [CrossRef] [PubMed]
  56. Sharma, A.; Sharma, D.; Verma, S.K. In silico identification of copper-binding proteins of Xanthomonas translucens pv. undulosa for their probable role in plant-pathogen interactions. PMPP Physiol. Mol. Plant Pathol. 2019, 106, 187–195. [Google Scholar] [CrossRef]
  57. Lima, W.C.; Paquola, A.C.; Varani, A.M.; Van Sluys, M.A.; Menck, C.F. Laterally transferred genomic islands in Xanthomonadales related to pathogenicity and primary metabolism: LGT islands in Xanthomonas. FEMS Microbiol. Lett. 2008, 281, 87–97. [Google Scholar] [CrossRef] [Green Version]
  58. Cabrejos, D.A.L.; Alexandrino, A.V.; Pereira, C.M.; Mendonça, D.C.; Pereira, H.D.; Novo-Mansur, M.T.M.; Garratt, R.C.; Goto, L.S. Structural characterization of a pathogenicity-related superoxide dismutase codified by a probably essential gene in Xanthomonas citri subsp. citri. PLoS ONE 2019, 14, e0209988. [Google Scholar] [CrossRef] [Green Version]
  59. O’Brien, J.A.; Daudi, A.; Butt, V.S.; Paul Bolwell, G. Reactive oxygen species and their role in plant defence and cell wall metabolism. Planta 2012, 236, 765–779. [Google Scholar] [CrossRef]
  60. Canchaya, C.; Fournous, G.; Brüssow, H. The impact of prophages on bacterial chromosomes: Prophage-chromosome interaction. Mol. Microbiol. 2004, 53, 9–18. [Google Scholar] [CrossRef]
  61. da Silva, A.C.R.; Ferro, J.A.; Reinach, F.C.; Farah, C.S.; Furlan, L.R.; Quaggio, R.B.; Monteiro-Vitorello, C.B.; Van Sluys, M.A.; Almeida, N.F.; Alves, L.M.C.; et al. Comparison of the genomes of two Xanthomonas pathogens with differing host specificities. Nature 2002, 417, 459–463. [Google Scholar] [CrossRef]
  62. Silva Junior, W.J.; Farias, A.R.G.; Lima, N.B.; Benko-Iseppon, A.M.; Aburjaile, F.; Balbino, V.Q.; Falcão, R.M.; Leitão Paiva Júnior, S.d.S.; Sousa-Paula, L.C.; Mariano, R.L.R.; et al. Complete genome sequence of Xanthomonas citri pv. anacardii strain IBSBF2579 from Brazil. Genome Announc. 2018, 6, e01574-17. [Google Scholar] [CrossRef]
Figure 1. Curve of Xanthomonas genus pan-genome development calculated with all 80 genomes.
Figure 1. Curve of Xanthomonas genus pan-genome development calculated with all 80 genomes.
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Figure 2. KEGG metabolic pathways on the total pan-genome of Xanthomonas.
Figure 2. KEGG metabolic pathways on the total pan-genome of Xanthomonas.
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Figure 3. Alignments of X. citri subsp. citri genomes and their genomic islands. PAI24 is well conserved for (A) strains AW13, AW14, AW15, and AW16, but not for others such as (B) BL18, FB19, gd2, and gd3. It is possible to observe that PAI24 does not present the complete region in the strains BL18, FB19, gd2, and gd3 showing a low identity (<70%) region.
Figure 3. Alignments of X. citri subsp. citri genomes and their genomic islands. PAI24 is well conserved for (A) strains AW13, AW14, AW15, and AW16, but not for others such as (B) BL18, FB19, gd2, and gd3. It is possible to observe that PAI24 does not present the complete region in the strains BL18, FB19, gd2, and gd3 showing a low identity (<70%) region.
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Figure 4. Alignments of X. campestris genomes and their genomic islands.
Figure 4. Alignments of X. campestris genomes and their genomic islands.
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Figure 5. Alignments of X. citri subsp. malvacearum genomes and their genomic islands. Strain XcmN1003 (yellow ring) presents the highest similarity amongst other strains of the same pathovar.
Figure 5. Alignments of X. citri subsp. malvacearum genomes and their genomic islands. Strain XcmN1003 (yellow ring) presents the highest similarity amongst other strains of the same pathovar.
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Figure 6. Alignments of X. citri pv. phaseoli var. fuscans genomes and genomic islands. The strain CFBP 7767 (inner-central ring) has the highest similarity among other strains of the same pathovar.
Figure 6. Alignments of X. citri pv. phaseoli var. fuscans genomes and genomic islands. The strain CFBP 7767 (inner-central ring) has the highest similarity among other strains of the same pathovar.
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Figure 7. Alignments of X. citri pv. aurantifolii genomes and genomic islands. Strain FDC1559 (brown inner ring) has the highest similarity among other strains of the same pathovar in this species.
Figure 7. Alignments of X. citri pv. aurantifolii genomes and genomic islands. Strain FDC1559 (brown inner ring) has the highest similarity among other strains of the same pathovar in this species.
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Figure 8. Alignments of X. citri pv. vignicola (A) and X. citri pv. anacardii (B) genomes and their genomic islands. Almost all pathogenicity islands identified in reference strains CFBP7111 (A), and IBSBF2579 (B) consisted of gap regions in the other strains.
Figure 8. Alignments of X. citri pv. vignicola (A) and X. citri pv. anacardii (B) genomes and their genomic islands. Almost all pathogenicity islands identified in reference strains CFBP7111 (A), and IBSBF2579 (B) consisted of gap regions in the other strains.
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Figure 9. Alignments of X. citri pv. glycines genomes and genomic islands. All pathogenicity islands identified in reference strain 12-2 are conserved in strain 8ra, except for PAI5.
Figure 9. Alignments of X. citri pv. glycines genomes and genomic islands. All pathogenicity islands identified in reference strain 12-2 are conserved in strain 8ra, except for PAI5.
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Figure 10. Genomic islands comparisons with (A) X. campestris pv. campestris ATCC33913 and (B) X. citri subsp. citri TX160197 against strains of X. citri pv. anacardii. The islands showed higher similarity for X. citri subsp. citri genomes than for X. campestris, but no genomic islands of both species were conserved in X. citri pv. anacardii genomes.
Figure 10. Genomic islands comparisons with (A) X. campestris pv. campestris ATCC33913 and (B) X. citri subsp. citri TX160197 against strains of X. citri pv. anacardii. The islands showed higher similarity for X. citri subsp. citri genomes than for X. campestris, but no genomic islands of both species were conserved in X. citri pv. anacardii genomes.
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Figure 11. Genomic islands comparisons with X. citri pv. aurantifolii FDC1559 against strains of X. citri pv. anacardii. The similarity panel was almost even for both species.
Figure 11. Genomic islands comparisons with X. citri pv. aurantifolii FDC1559 against strains of X. citri pv. anacardii. The similarity panel was almost even for both species.
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Table 1. Pan-genomes results (core, accessory, and unique) for X. campestris and X. citri genomes individually, and Xanthomonas genus pan-genome with all 80 genomes.
Table 1. Pan-genomes results (core, accessory, and unique) for X. campestris and X. citri genomes individually, and Xanthomonas genus pan-genome with all 80 genomes.
CoreAcessoryUnique
Xanthomonas2585275011,562
X. campestris341318131173
X. citri293625619055
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Ariute, J.C.; Rodrigues, D.L.N.; de Castro Soares, S.; Azevedo, V.; Benko-Iseppon, A.M.; Aburjaile, F.F. Comparative Genomic Analysis of Phytopathogenic Xanthomonas Species Suggests High Level of Genome Plasticity Related to Virulence and Host Adaptation. Bacteria 2022, 1, 218-241. https://doi.org/10.3390/bacteria1040017

AMA Style

Ariute JC, Rodrigues DLN, de Castro Soares S, Azevedo V, Benko-Iseppon AM, Aburjaile FF. Comparative Genomic Analysis of Phytopathogenic Xanthomonas Species Suggests High Level of Genome Plasticity Related to Virulence and Host Adaptation. Bacteria. 2022; 1(4):218-241. https://doi.org/10.3390/bacteria1040017

Chicago/Turabian Style

Ariute, Juan Carlos, Diego Lucas Neres Rodrigues, Siomar de Castro Soares, Vasco Azevedo, Ana Maria Benko-Iseppon, and Flávia Figueira Aburjaile. 2022. "Comparative Genomic Analysis of Phytopathogenic Xanthomonas Species Suggests High Level of Genome Plasticity Related to Virulence and Host Adaptation" Bacteria 1, no. 4: 218-241. https://doi.org/10.3390/bacteria1040017

APA Style

Ariute, J. C., Rodrigues, D. L. N., de Castro Soares, S., Azevedo, V., Benko-Iseppon, A. M., & Aburjaile, F. F. (2022). Comparative Genomic Analysis of Phytopathogenic Xanthomonas Species Suggests High Level of Genome Plasticity Related to Virulence and Host Adaptation. Bacteria, 1(4), 218-241. https://doi.org/10.3390/bacteria1040017

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