Complete genome sequences of six copper-resistant Xanthomonas strains causing bacterial spot of solaneous plants, Bblonging to X. gardneri, X. euvesicatoria, and X. vesicatoria, using long-read technology

Xanthomonas vesicatoria, Xanthomonas euvesicatoria, and Xanthomonas gardneri cause bacterial spot disease. Copper has been applied since the 1920s as part of integrated management programs. The first copper-resistant strains were reported some decades later. Here, we fully sequenced six Xanthomonas strains pathogenic to tomato and/or pepper and having a copper-resistant phenotype. (Résumé d'auteur

Adaptation of genetically monomorphic bacteria: evolution of copper resistance through multiple horizontal gene transfers of complex and versatile mobile genetic elements

Copper-based antimicrobial compounds are widely used to control plant bacterial pathogens. Pathogens have adapted in response to this selective pressure. Xanthomonas citri pv. citri, a major citrus pathogen causing Asiatic citrus canker, was first reported to carry plasmid-encoded copper resistance in Argentina. This phenotype was conferred by the copLAB gene system. The emergence of resistant strains has since been reported in Réunion and Martinique. Using microsatellite-based genotyping and copLAB PCR, we demonstrated that the genetic structure of the copper-resistant strains from these three regions was made up of two distant clusters and varied for the detection of copLAB amplicons. In order to investigate this pattern more closely, we sequenced six copper-resistant X. citri pv. citri strains from Argentina, Martinique and Réunion, together with reference copper-resistant Xanthomonas and Stenotrophomonas strains using long-read sequencing technology. Genes involved in copper resistance were found to be strain-dependent with the novel identification in X. citri pv. citri of copABCD and a cus heavy metal efflux resistance-nodulation-division system. The genes providing the adaptive trait were part of a mobile genetic element similar to Tn3-like transposons and included in a conjugative plasmid. This indicates the system's great versatility. The mining of all available bacterial genomes suggested that, within the bacterial community, the spread of copper resistance associated to mobile elements and their plasmid environments was primarily restricted to the Xanthomonadaceae family

Deciphering copper resistance in Xanthomonas citri pv. citri

International audienceCopper-based compounds are widely used in integrated pest management (1PM) programs aiming at controlling agriculturally important plant bacterial pathogens and the latter have adapted in response to this selective pressure. Copper resistance of Xanthomonas citri pv. citri (Xcc), a major citrus pathogen worldwide causing Asiatic citrus canker, was first observed in Argentina two decades ago and subsequently reported as a coplAB-based, plasmid-encoded system. The emergence of resistant strains has since been reported in Réunion (South West lndian Ocean) and Martinique (Eastern Caribbean Sea). Disease severity was found markedly increased in groves established with susceptible cultivars and infected with copper-resistant Xcc. Using tandem repeat-based genotyping and coplAB PCR, we demonstrated that the genetic structure of the copper-resistant strains from these three regions was made up of two distant clusters and varied for the detection of coplAB amplicons. ln order to investigate this pattern more closely, we sequenced six copper-resistant Xcc strains from Argentina, Martinique and Réunion, together with reference copper-resistant Xanthomonas and Stenotrophomonas strains using long-read sequencing technology. Genes involved in copper resistance were found to be straindependent with the novel identification in Xcc of copABCD and a eus heavy metal efflux resistancenodulation- division system. The genes providing the adaptive trait were part of a mobile genetic element similar to Tn3-like transposons and included in a conjugative plasmid. The mining of all bacterial genomes available from public databases suggested that the mobile elements containing copper resistance genes and their plasmid environments were primarily detected in the Xanthomonadaceae family

Deciphering copper resistance in Xanthomonas citri pv. citri

International audienceCopper-based compounds are widely used in integrated pest management (1PM) programs aiming at controlling agriculturally important plant bacterial pathogens and the latter have adapted in response to this selective pressure. Copper resistance of Xanthomonas citri pv. citri (Xcc), a major citrus pathogen worldwide causing Asiatic citrus canker, was first observed in Argentina two decades ago and subsequently reported as a coplAB-based, plasmid-encoded system. The emergence of resistant strains has since been reported in Réunion (South West lndian Ocean) and Martinique (Eastern Caribbean Sea). Disease severity was found markedly increased in groves established with susceptible cultivars and infected with copper-resistant Xcc. Using tandem repeat-based genotyping and coplAB PCR, we demonstrated that the genetic structure of the copper-resistant strains from these three regions was made up of two distant clusters and varied for the detection of coplAB amplicons. ln order to investigate this pattern more closely, we sequenced six copper-resistant Xcc strains from Argentina, Martinique and Réunion, together with reference copper-resistant Xanthomonas and Stenotrophomonas strains using long-read sequencing technology. Genes involved in copper resistance were found to be straindependent with the novel identification in Xcc of copABCD and a eus heavy metal efflux resistancenodulation- division system. The genes providing the adaptive trait were part of a mobile genetic element similar to Tn3-like transposons and included in a conjugative plasmid. The mining of all bacterial genomes available from public databases suggested that the mobile elements containing copper resistance genes and their plasmid environments were primarily detected in the Xanthomonadaceae family