title: A "repertoire for repertoire" hypothesis: repertoires of type three effectors are candidate determinants of host specificity in Xanthomonas.
abstract: BACKGROUND
  The genetic basis of host specificity for animal and plant pathogenic bacteria remains poorly understood. For plant pathogenic bacteria, host range is restricted to one or a few host plant species reflecting a tight adaptation to specific hosts.
  
  
  RESULTS
  Two hypotheses can be formulated to explain host specificity: either it can be explained by the phylogenetic position of the strains, or by the association of virulence genes enabling a pathological convergence of phylogenically distant strains. In this latter hypothesis, host specificity would result from the interaction between repertoires of bacterial virulence genes and repertoires of genes involved in host defences. To challenge these two hypotheses, we selected 132 Xanthomonas axonopodis strains representative of 18 different pathovars which display different host range. First, the phylogenetic position of each strain was determined by sequencing the housekeeping gene rpoD. This study showed that many pathovars of Xanthomonas axonopodis are polyphyletic. Second, we investigated the distribution of 35 type III effector genes (T3Es) in these strains by both PCR and hybridization methods. Indeed, for pathogenic bacteria T3Es were shown to trigger and to subvert host defences. Our study revealed that T3E repertoires comprise core and variable gene suites that likely have distinct roles in pathogenicity and different evolutionary histories. Our results showed a correspondence between composition of T3E repertoires and pathovars of Xanthomonas axonopodis. For polyphyletic pathovars, this suggests that T3E genes might explain a pathological convergence of phylogenetically distant strains. We also identified several DNA rearrangements within T3E genes, some of which correlate with host specificity of strains.
  
  
  CONCLUSIONS
  These data provide insight into the potential role played by T3E genes for pathogenic bacteria and support a "repertoire for repertoire" hypothesis that may explain host specificity. Our work provides resources for functional and evolutionary studies aiming at understanding host specificity of pathogenic bacteria, functional redundancy between T3Es and the driving forces shaping T3E repertoires.
authors.affiliation: Département Santé des Plantes et Environnement, Institut National de la Recherche Agronomique, Beaucouzé, France.
authors.forename: Ahmed
authors.initials: A
authors.lastname: Hajri
authors.forename: Chrystelle
authors.initials: C
authors.lastname: Brin
authors.forename: Gilles
authors.initials: G
authors.lastname: Hunault
authors.forename: Frédéric
authors.initials: F
authors.lastname: Lardeux
authors.forename: Christophe
authors.initials: C
authors.lastname: Lemaire
authors.forename: Charles
authors.initials: C
authors.lastname: Manceau
authors.forename: Tristan
authors.initials: T
authors.lastname: Boureau
authors.forename: Stéphane
authors.initials: S
authors.lastname: Poussier
mesh_terms: D001419:Bacteria / Q000145:classification / Q000302:isolation & purification; D018407:Bacterial Physiological Phenomena; D005798:Genes, Bacterial; D054884:Host-Pathogen Interactions; D010802:Phylogeny; D010944:Plants / Q000382:microbiology; D016133:Polymerase Chain Reaction; D014974:Xanthomonas / Q000145:classification / Q000235:genetics / Q000502:physiology*
references.citation: Mol Plant Microbe Interact. 2004 Aug;17(8):931-40
references.pmid: 15305614
references.citation: PLoS One. 2008 Jun 04;3(6):e2369
references.pmid: 18523661
references.citation: Phytopathology. 2005 Aug;95(8):918-25
references.pmid: 18944414
references.citation: Phytopathology. 2000 Jul;90(7):683-90
references.pmid: 18944486
references.citation: Trends Microbiol. 2003 Oct;11(10):479-87
references.pmid: 14557031
references.citation: Genetics. 2004 Jul;167(3):1341-60
references.pmid: 15280247
references.citation: Annu Rev Microbiol. 2000;54:641-79
references.pmid: 11018140
references.citation: Phytopathology. 2007 Dec;97(12):1568-77
references.pmid: 18943717
references.citation: Trends Microbiol. 1999 May;7(5):191-5
references.pmid: 10354593
references.citation: Proc Natl Acad Sci U S A. 1998 Mar 17;95(6):3140-5
references.pmid: 9501229
references.citation: Phytopathology. 2005 Sep;95(9):1098-111
references.pmid: 18943308
references.citation: Proc Natl Acad Sci U S A. 2004 Nov 23;101(47):16624-9
references.pmid: 15545602
references.citation: Plant J. 2007 Aug;51(4):604-16
references.pmid: 17573803
references.citation: Mol Plant Microbe Interact. 2006 Nov;19(11):1151-8
references.pmid: 17073298
references.citation: Mol Plant Microbe Interact. 2000 Sep;13(9):911-21
references.pmid: 10975648
references.citation: Phytopathology. 2000 Jul;90(7):677-82
references.pmid: 18944485
references.citation: Cell Microbiol. 2008 Feb;10(2):285-92
references.pmid: 18034865
references.citation: Annu Rev Phytopathol. 2004;42:385-414
references.pmid: 15283671
references.citation: Mol Microbiol. 2004 Oct;54(2):353-65
references.pmid: 15469508
references.citation: Mol Plant Microbe Interact. 2005 Dec;18(12):1306-17
references.pmid: 16478050
references.citation: Annu Rev Phytopathol. 2007;45:129-51
references.pmid: 17367270
references.citation: BMC Microbiol. 2007 Aug 30;7:81
references.pmid: 17760980
references.citation: Nat Rev Microbiol. 2006 Nov;4(11):811-25
references.pmid: 17041629
references.citation: PLoS One. 2008;3(11):e3828
references.pmid: 19043590
references.citation: Mol Microbiol. 2006 Oct;62(1):26-44
references.pmid: 16942603
references.citation: Plant J. 2004 Feb;37(4):554-65
references.pmid: 14756767
references.citation: PLoS Biol. 2005 May;3(5):e130
references.pmid: 15799709
references.citation: Science. 2001 May 11;292(5519):1096-9
references.pmid: 11352062
references.citation: J Clin Microbiol. 2005 Jan;43(1):66-73
references.pmid: 15634952
references.citation: Infect Genet Evol. 2008 May;8(3):386-93
references.pmid: 18321793
references.citation: Syst Appl Microbiol. 2008 Oct;31(5):366-77
references.pmid: 18783906
references.citation: Mol Plant Microbe Interact. 2000 Dec;13(12):1346-55
references.pmid: 11106027
references.citation: Nature. 2007 Oct 18;449(7164):835-42
references.pmid: 17943120
references.citation: FEMS Microbiol Lett. 2002 Sep 24;215(1):23-31
references.pmid: 12393196
references.citation: Proc Natl Acad Sci U S A. 1999 Sep 14;96(19):10875-80
references.pmid: 10485919
references.citation: Appl Environ Microbiol. 2006 Feb;72(2):1072-8
references.pmid: 16461651
references.citation: J Bacteriol. 1998 Apr;180(8):2244-7
references.pmid: 9555912
references.citation: Proc Natl Acad Sci U S A. 2000 Apr 25;97(9):4856-61
references.pmid: 10781092
references.citation: Int J Syst Evol Microbiol. 2000 Mar;50 Pt 2:665-677
references.pmid: 10758874
references.citation: Genetics. 2006 Oct;174(2):1041-56
references.pmid: 16951068
references.citation: Mol Plant Microbe Interact. 1998 May;11(5):423-8
references.pmid: 9574509
references.citation: Proc Natl Acad Sci U S A. 2005 Mar 22;102(12):4419-24
references.pmid: 15755815
references.citation: Appl Environ Microbiol. 2005 May;71(5):2418-32
references.pmid: 15870329
references.citation: OMICS. 2005 Summer;9(2):160-72
references.pmid: 15969648
references.citation: Appl Environ Microbiol. 2005 Apr;71(4):2008-15
references.pmid: 15812033
references.citation: Plant J. 2005 Mar;41(6):801-14
references.pmid: 15743446
references.citation: Nucleic Acids Res. 2005 Jan 26;33(2):577-86
references.pmid: 15673718
references.citation: J Bacteriol. 1990 Jan;172(1):143-8
references.pmid: 2152895
references.citation: Mol Plant Microbe Interact. 2006 Feb;19(2):99-111
references.pmid: 16529372
references.citation: Curr Biol. 2005 Dec 20;15(24):2230-5
references.pmid: 16360685
references.citation: Mol Plant Microbe Interact. 1999 Jan;12(1):35-44
references.pmid: 9885191
references.citation: Mol Plant Microbe Interact. 2004 Nov;17(11):1192-200
references.pmid: 15553245
references.citation: PLoS Pathog. 2009 Apr;5(4):e1000388
references.pmid: 19381254
references.citation: Curr Opin Microbiol. 2009 Feb;12(1):37-43
references.pmid: 19168386
references.citation: PLoS Genet. 2006 Dec;2(12):e209
references.pmid: 17194219
references.citation: Int J Med Microbiol. 2005 Oct;295(6-7):455-62
references.pmid: 16238019
references.citation: Appl Environ Microbiol. 1993 Mar;59(3):851-9
references.pmid: 16348894
references.citation: Appl Environ Microbiol. 2006 Nov;72(11):7359-64
references.pmid: 16963554
references.citation: Mol Plant Microbe Interact. 2004 Jul;17(7):771-9
references.pmid: 15242171
references.citation: Curr Opin Plant Biol. 2007 Aug;10(4):349-57
references.pmid: 17625953
references.citation: Trends Genet. 2007 Jun;23(6):293-300
references.pmid: 17434232
references.citation: Mol Microbiol. 1997 Dec;26(5):1057-69
references.pmid: 9426142
references.citation: Bioinformatics. 1998;14(9):817-8
references.pmid: 9918953
references.citation: Mol Plant Microbe Interact. 2009 Jun;22(6):747-57
references.pmid: 19445599
references.citation: Appl Environ Microbiol. 2004 Apr;70(4):1999-2012
references.pmid: 15066790
references.citation: Genome Res. 2005 Jun;15(6):757-67
references.pmid: 15899963
references.citation: J Clin Microbiol. 2007 Oct;45(10):3366-76
references.pmid: 17652485
references.citation: Appl Environ Microbiol. 2008 May;74(10):3295-301
references.pmid: 18359831
references.citation: Curr Opin Plant Biol. 2004 Aug;7(4):384-90
references.pmid: 15231260
references.citation: Int J Syst Evol Microbiol. 2004 Jan;54(Pt 1):15-24
references.pmid: 14742454
references.citation: Annu Rev Microbiol. 2006;60:425-49
references.pmid: 16753033
references.citation: Proc Natl Acad Sci U S A. 2005 Feb 15;102(7):2549-54
references.pmid: 15701698
references.citation: J Bacteriol. 2008 Jan;190(1):343-55
references.pmid: 17951377
references.citation: J Plant Physiol. 2006 Feb;163(3):233-55
references.pmid: 16386329
references.citation: Science. 2002 Mar 1;295(5560):1722-6
references.pmid: 11872842
references.citation: Annu Rev Phytopathol. 1998;36:41-58
references.pmid: 15012492
references.citation: Appl Environ Microbiol. 2008 May;74(9):2669-78
references.pmid: 18326683
references.citation: Curr Opin Microbiol. 2006 Feb;9(1):28-32
references.pmid: 16384724
references.citation: J Bacteriol. 2006 May;188(10):3697-708
references.pmid: 16672623
references.citation: Mol Plant Microbe Interact. 2005 Feb;18(2):142-9
references.pmid: 15720083
references.citation: Mol Microbiol. 2003 Sep;49(5):1239-51
references.pmid: 12940984
references.citation: Annu Rev Phytopathol. 2001;39:187-224
references.pmid: 11701864
references.citation: Mol Plant Pathol. 2005 May 1;6(3):335-45
references.pmid: 20565662
references.citation: Mol Plant Microbe Interact. 2009 Feb;22(2):176-89
references.pmid: 19132870
references.citation: Genome Biol. 2007;8(10):R218
references.pmid: 17927820
references.citation: Appl Environ Microbiol. 2007 Mar;73(5):1678-82
references.pmid: 17209062
references.citation: Nature. 2002 May 23;417(6887):459-63
references.pmid: 12024217
references.citation: Mol Plant Pathol. 2003 May 1;4(3):141-57
references.pmid: 20569374
references.citation: Microbiol Mol Biol Rev. 1998 Sep;62(3):725-74
references.pmid: 9729608
references.citation: Nature. 2006 Nov 16;444(7117):323-9
references.pmid: 17108957
references.citation: PLoS Pathog. 2006 Oct;2(10):e104
references.pmid: 17040127
references.citation: Mol Plant Microbe Interact. 2006 Mar;19(3):342-9
references.pmid: 16570663
references.citation: Nature. 1990 Jul 26;346(6282):385-6
references.pmid: 2374611
references.citation: Proc Natl Acad Sci U S A. 2005 Aug 2;102(31):11064-9
references.pmid: 16043691
references.citation: Mol Biol Evol. 2006 Nov;23(11):2049-57
references.pmid: 16882701
references.citation: J Bacteriol. 2007 Jan;189(2):377-87
references.pmid: 17085551
references.citation: Methods Mol Biol. 2000;132:115-30
references.pmid: 10547834
references.citation: BMC Microbiol. 2009 Feb 19;9 Suppl 1:S4
references.pmid: 19278552
references.citation: Trends Microbiol. 1999 Dec;7(12):482-7
references.pmid: 10603483
references.citation: J Cell Sci. 2007 Sep 15;120(Pt 18):3271-8
references.pmid: 17726062
references.citation: Res Microbiol. 2008 Apr;159(3):216-20
references.pmid: 18281198
references.citation: BMC Microbiol. 2009 Feb 19;9 Suppl 1:S1
references.pmid: 19278549
references.citation: J Bacteriol. 1995 Sep;177(17):4963-8
references.pmid: 7665472
references.citation: Appl Environ Microbiol. 2005 Jul;71(7):3778-85
references.pmid: 16000789
references.citation: J Bacteriol. 2003 Dec;185(24):7092-102
references.pmid: 14645268
references.citation: Mol Plant Microbe Interact. 2006 Nov;19(11):1180-92
references.pmid: 17073301
references.citation: J Bacteriol. 2005 Nov;187(21):7254-66
references.pmid: 16237009
references.citation: Phytopathology. 2004 Jun;94(6):593-603
references.pmid: 18943484
references.citation: J Bacteriol. 2006 Nov;188(21):7652-60
references.pmid: 16936021