title: Comparative genomics of cultured and uncultured strains suggests genes essential for free-living growth of Liberibacter.
abstract: The full genomes of two uncultured plant pathogenic Liberibacter, Ca. Liberibacter asiaticus and Ca. Liberibacter solanacearum, are publicly available. Recently, the larger genome of a closely related cultured strain, Liberibacter crescens BT-1, was described. To gain insights into our current inability to culture most Liberibacter, a comparative genomics analysis was done based on the RAST, KEGG, and manual annotations of these three organisms. In addition, pathogenicity genes were examined in all three bacteria. Key deficiencies were identified in Ca. L. asiaticus and Ca. L. solanacearum that might suggest why these organisms have not yet been cultured. Over 100 genes involved in amino acid and vitamin synthesis were annotated exclusively in L. crescens BT-1. However, none of these deficiencies are limiting in the rich media used to date. Other genes exclusive to L. crescens BT-1 include those involved in cell division, the stringent response regulatory pathway, and multiple two component regulatory systems. These results indicate that L. crescens is capable of growth under a much wider range of conditions than the uncultured Liberibacter strains. No outstanding differences were noted in pathogenicity-associated systems, suggesting that L. crescens BT-1 may be a plant pathogen on an as yet unidentified host.
authors.affiliation: Microbiology and Cell Science Department, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, Florida, United States of America.
authors.forename: Jennie R
authors.initials: JR
authors.lastname: Fagen
authors.affiliation: Microbiology and Cell Science Department, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, Florida, United States of America.
authors.forename: Michael T
authors.initials: MT
authors.lastname: Leonard
authors.affiliation: Microbiology and Cell Science Department, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, Florida, United States of America.
authors.forename: Connor M
authors.initials: CM
authors.lastname: McCullough
authors.affiliation: Mathematics and Computer Science Division, Argonne National Laboratory, Argonne, Illinois, United States of America.
authors.forename: Janaka N
authors.initials: JN
authors.lastname: Edirisinghe
authors.affiliation: Mathematics and Computer Science Division, Argonne National Laboratory, Argonne, Illinois, United States of America.
authors.forename: Christopher S
authors.initials: CS
authors.lastname: Henry
authors.affiliation: Plant Pathology Department, Citrus Research and Development Center, Institute of Food and Agricultural Sciences, University of Florida, Lake Alfred, Florida, United States of America.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Davis
authors.affiliation: Microbiology and Cell Science Department, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, Florida, United States of America.
authors.forename: Eric W
authors.initials: EW
authors.lastname: Triplett
mesh_terms: D002244:Carbon / Q000378:metabolism; D002462:Cell Membrane / Q000378:metabolism; D046508:Culture Techniques; D004579:Electron Transport / Q000235:genetics; D005798:Genes, Bacterial / Q000235:genetics*; D020043:Genes, Essential; D023281:Genomics; D006706:Homeostasis / Q000235:genetics; D012230:Rhizobiaceae / Q000166:cytology / Q000235:genetics* / Q000254:growth & development* / Q000378:metabolism; D013045:Species Specificity
chemical_list: D002244:Carbon