Amplified fragment length polymorphism and multilocus sequence analysis-based genotypic relatedness among pathogenic variants of Xanthomonas citri pv. citri and Xanthomonas campestris pv. bilvae

• Published in: International journal of systematic and evolutionary microbiology Vol. 60; no. Pt 3; pp. 515 - 525
• Main Authors: THI NGOC, Lan Bui, VERNIERE, Christian, JOUEN, Emmanuel, AH-YOU, Nathalie, LEFEUVRE, Pierre, CHIROLEU, Frédéric, GAGNEVIN, Lionel, PRUVOST, Olivier
• Format: Journal Article
• Language: English
• Published: Reading Society for General Microbiology 01-03-2010
• Subjects: Amplified Fragment Length Polymorphism Analysis; Bacterial Proteins - genetics; Bacteriology; Biological and medical sciences; Citrus - microbiology; Fundamental and applied biological sciences. Psychology; Genotype; Microbiology; Molecular Sequence Data; Phylogeny; Plant Diseases - microbiology; Polymorphism, Genetic; Sequence Analysis, DNA; Systematics; Xanthomonas - classification; Xanthomonas - genetics; Xanthomonas - isolation & purification; Xanthomonas - pathogenicity; Pseudomonadales; Variant; Taxonomy; Pathogenic; Xanthomonas campestris pv. citri; Bacteria; Pseudomonadaceae; Amplified fragment length polymorphism marker
• ISSN: 1466-5026; 1466-5034
• DOI: 10.1099/ijs.0.009514-0

Three pathogenic variants (i.e. pathotypes) have been described within Xanthomonas citri pv. citri, the causal agent of Asiatic citrus canker. Pathotype A strains naturally infect a wide range of Citrus species and members of some related genera. In contrast, pathotypes A* and A(w) have narrow host ranges within the genus Citrus and have been isolated from Mexican lime (Citrus aurantifolia L.) and from Mexican lime and alemow (Citrus macrophylla L.), respectively. We used amplified fragment length polymorphism (AFLP) and multilocus sequence analysis (MLSA) based on four partial housekeeping gene sequences (atpD, dnaK, efp and gyrB ) for the genotypic classification of Xanthomonas citri pv. citri and the poorly characterized citrus pathogen Xanthomonas campestris pv. bilvae. A Mantel test showed that genetic distances derived from AFLP and MLSA were highly correlated. X. campestris pv. bilvae showed a close relatedness to the type strain of X. citri, indicating that this pathovar should be reclassified as X. citri pv. bilvae. All pathotype A* and A(w) strains were most closely related to X. citri pv. citri strains with a wide host range (pathotype A), confirming previous DNA-DNA hybridization data. Pathotype A(w) should be considered a junior synonym of pathotype A* on the basis of pathogenicity tests, AFLP, MLSA and PCR using pathovar-specific primers. Evolutionary genome divergences computed from AFLP data suggested that pathotype A* (including A(w) strains) is a group of strains that shows a wider genetic diversity than pathotype A.