+1 Recommend
0 collections
      • Record: found
      • Abstract: found
      • Article: found
      Is Open Access

      Natural Genetic Variation of Xanthomonas campestris pv. campestris Pathogenicity on Arabidopsis Revealed by Association and Reverse Genetics


      Read this article at

          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.


          The pathogenic bacterium Xanthomonas campestris pv. campestris, the causal agent of black rot of Brassicaceae, manipulates the physiology and the innate immunity of its hosts. Association genetic and reverse-genetic analyses of a world panel of 45 X. campestris pv. campestris strains were used to gain understanding of the genetic basis of the bacterium’s pathogenicity to Arabidopsis thaliana. We found that the compositions of the minimal predicted type III secretome varied extensively, with 18 to 28 proteins per strain. There were clear differences in aggressiveness of those X. campestris pv. campestris strains on two Arabidopsis natural accessions. We identified 3 effector genes ( xopAC, xopJ5, and xopAL2) and 67 amplified fragment length polymorphism (AFLP) markers that were associated with variations in disease symptoms. The nature and distribution of the AFLP markers remain to be determined, but we observed a low linkage disequilibrium level between predicted effectors and other significant markers, suggesting that additional genetic factors make a meaningful contribution to pathogenicity. Mutagenesis of type III effectors in X. campestris pv. campestris confirmed that xopAC functions as both a virulence and an avirulence gene in Arabidopsis and that xopAM functions as a second avirulence gene on plants of the Col-0 ecotype. However, we did not detect the effect of any other effector in the X. campestris pv. campestris 8004 strain, likely due to other genetic background effects. These results highlight the complex genetic basis of pathogenicity at the pathovar level and encourage us to challenge the agronomical relevance of some virulence determinants identified solely in model strains.


          The identification and understanding of the genetic determinants of bacterial virulence are essential to be able to design efficient protection strategies for infected plants. The recent availability of genomic resources for a limited number of pathogen isolates and host genotypes has strongly biased our research toward genotype-specific approaches. Indeed, these do not consider the natural variation in both pathogens and hosts, so their applied relevance should be challenged. In our study, we exploited the genetic diversity of Xanthomonas campestris pv. campestris, the causal agent of black rot on Brassicaceae (e.g., cabbage), to mine for pathogenicity determinants. This work evidenced the contribution of known and unknown loci to pathogenicity relevant at the pathovar level and identified these virulence determinants as prime targets for breeding resistance to X. campestris pv. campestris in Brassicaceae.

          Related collections

          Most cited references45

          • Record: found
          • Abstract: not found
          • Article: not found

          On the Adaptive Control of the False Discovery Rate in Multiple Testing With Independent Statistics

            • Record: found
            • Abstract: found
            • Article: not found

            Replication of an origin-containing derivative of plasmid RK2 dependent on a plasmid function provided in trans.

            pRK212.2, a derivative of the broad host range plasmid RK2, contains two EcoRI cleavage fragments, A and B, neither of which can replicate by itself in Escherichia coli. Fragment A (41.7 kilobases), but not fragment B (14.4 kilobases), can be cloned by insertion into the unrelated plasmids mini-F and ColE1. Fragment B contains the origin of replication and the ampicillin-resistance determinant of RK2. Transformation of E. coli cells containing the mini-F-fragment A hybrid plasmid with fragment B DNA results in the recircularization and replication of fragment B as a nonmobilizable plasmid (pRK2067) with the copy number and incompatibility properties of RK2. Fragment B cannot be cloned in the absence of fragment A because the latter fragment suppresses a function, specified by fragment B, that results in loss of host cell viability. A small segment (2.4 kilobases) of fragment B that contains the RK2 origin of replication but no longer affects host cell growth in the absence of fragment A had been cloned previously by insertion into a ColE1 plasmid. This hybrid plasmid, designated pRK256, will replicate in E. coli polA mutants only when a fragment A-bearing helper plasmid is present. These results demonstrate that the potentially lethal function specified by fragment B of RK2 is not necessary for replication and that at least one trans-acting function is directly involved in RK2 replication.
              • Record: found
              • Abstract: not found
              • Article: not found

              Small mobilizable multi-purpose cloning vectors derived from the Escherichia coli plasmids pK18 and pK19: selection of defined deletions in the chromosome of Corynebacterium glutamicum


                Author and article information

                American Society of Microbiology (1752 N St., N.W., Washington, DC )
                4 June 2013
                May-Jun 2013
                : 4
                : 3
                : e00538-12
                INRA, Laboratoire des Interactions Plantes Micro-organismes (LIPM), UMR 441, Castanet-Tolosan, France [ a ]
                CNRS, LIPM, UMR 2594, Castanet-Tolosan, France [ b ]
                INRA, UMR, 1345 IRHS, Beaucouzé, France [ c ]
                Université d’Angers, UMR, 1345 IRHS, Beaucouzé, France [ d ]
                Université de Toulouse, Université Paul Sabatier, Toulouse, France [ e ]
                Agrocampus Ouest, Centre d’Angers, Institut National d’Horticulture et de Paysage, UMR, 1345 IRHS, Beaucouzé, France [ f ]
                Author notes
                Address correspondence to Laurent D. Noël, laurent.noel@ 123456toulouse.inra.fr , or Anne Genissel, anne.genissel@ 123456versailles.inra.fr .

                Present address: Anne Genissel, INRA-AgroParisTech BIOGER, Thiverval Grignon, France; Ahmed Hajri, INRA, UMR 1349 IGEPP, Le Rheu, France; Matthieu Chabannes, CIRAD, UMR BGPI, Montpellier, France; Perrine David, HM Clause, La Bohalle, France; Stéphane Poussier, Université de la Réunion, UMR C53 PVBMT, Saint-Denis, France.

                E.G. and A.G. contributed equally to the work.

                Invited Editor David Guttman, University of Toronto Editor Frederick Ausubel, Massachusetts General Hospital

                Copyright © 2013 Guy et al.

                This is an open-access article distributed under the terms of the Creative Commons Attribution-Noncommercial-ShareAlike 3.0 Unported license, which permits unrestricted noncommercial use, distribution, and reproduction in any medium, provided the original author and source are credited.

                : 26 February 2013
                : 10 May 2013
                Page count
                Pages: 13
                Research Article
                Custom metadata
                May/June 2013

                Life sciences
                Life sciences


                Comment on this article