Open Access Highly Accessed Research article

Novel insights into the genomic basis of citrus canker based on the genome sequences of two strains of Xanthomonas fuscans subsp. aurantifolii

Leandro M Moreira12, Nalvo F Almeida13, Neha Potnis3, Luciano A Digiampietri1214, Said S Adi13, Julio C Bortolossi5, Ana C da Silva9, Aline M da Silva2, Fabrício E de Moraes5, Julio C de Oliveira56, Robson F de Souza2, Agda P Facincani5, André L Ferraz5, Maria I Ferro5, Luiz R Furlan7, Daniele F Gimenez5, Jeffrey B Jones3, Elliot W Kitajima10, Marcelo L Laia58, Rui P Leite17, Milton Y Nishiyama2, Julio Rodrigues Neto11, Letícia A Nociti5, David J Norman18, Eric H Ostroski14, Haroldo A Pereira5, Brian J Staskawicz19, Renata I Tezza5, Jesus A Ferro5, Boris A Vinatzer4 and João C Setubal1516*

Author Affiliations

1 Departamento de Ciências Biológicas, Instituto de Ciências Exatas e Biológicas, Campus Morro do Cruzeiro, Universidade Federal de Ouro Preto, Ouro Preto, MG, Brazil

2 Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, SP, Brazil

3 Department of Plant Pathology, University of Florida, Gainesville, FL, USA

4 Department of Plant Pathology, Physiology and Weed Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA

5 Departamento de Tecnologia, Faculdade de Ciências Agrárias e Veterinárias de Jaboticabal, UNESP - Univ. Estadual Paulista, Jaboticabal, SP, Brazil

6 Departamento de Ciências Biológicas, Campus de Diadema, Universidade Federal de São Paulo, São Paulo, SP, Brazil

7 Departamento de Melhoramento e Nutrição Animal, Faculdade de Medicina Veterinária e Zootecnia de Botucatu, UNESP - Univ. Estadual Paulista, SP, Brazil

8 Departamento de Engenharia Florestal, Centro de Ciências Agroveterinárias, Universidade do Estado de Santa Catarina, Lages, SC, Brazil

9 Allelyx Applied Genomics, Campinas, SP, Brazil

10 Núcleo de apoio à pesquisa em microscopia eletrônica aplicada à pesquisa agropecuária, Escola Superior de Agricultura Luiz de Queiroz, Universidade de São Paulo, Piracicaba, SP, Brazil

11 Laboratório de Bacteriologia Vegetal, Instituto Biológico Campinas, Campinas, SP, Brazil

12 Escola de Artes, Ciências, e Humanidades, Universidade de São Paulo, São Paulo, SP, Brazil

13 Faculdade de Computação, Universidade Federal do Mato Grosso do Sul, Campo Grande, MS, Brazil

14 Laboratório de Bioinformática, Instituto de Computação, Universidade Estadual de Campinas, Campinas, SP, Brazil

15 Virginia Bioinformatics Institute, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA

16 Department of Computer Science, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA

17 Instituto Agronômico do Paraná, Londrina, PR, Brazil

18 Institute of Food and Agricultural Sciences, Mid-Florida Research & Education Center, University of Florida, Gainesville, FL, USA

19 Department of Plant & Microbial Biology, University of California, Berkeley, Berkeley, CA, USA

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BMC Genomics 2010, 11:238  doi:10.1186/1471-2164-11-238

Published: 13 April 2010



Citrus canker is a disease that has severe economic impact on the citrus industry worldwide. There are three types of canker, called A, B, and C. The three types have different phenotypes and affect different citrus species. The causative agent for type A is Xanthomonas citri subsp. citri, whose genome sequence was made available in 2002. Xanthomonas fuscans subsp. aurantifolii strain B causes canker B and Xanthomonas fuscans subsp. aurantifolii strain C causes canker C.


We have sequenced the genomes of strains B and C to draft status. We have compared their genomic content to X. citri subsp. citri and to other Xanthomonas genomes, with special emphasis on type III secreted effector repertoires. In addition to pthA, already known to be present in all three citrus canker strains, two additional effector genes, xopE3 and xopAI, are also present in all three strains and are both located on the same putative genomic island. These two effector genes, along with one other effector-like gene in the same region, are thus good candidates for being pathogenicity factors on citrus. Numerous gene content differences also exist between the three cankers strains, which can be correlated with their different virulence and host range. Particular attention was placed on the analysis of genes involved in biofilm formation and quorum sensing, type IV secretion, flagellum synthesis and motility, lipopolysacharide synthesis, and on the gene xacPNP, which codes for a natriuretic protein.


We have uncovered numerous commonalities and differences in gene content between the genomes of the pathogenic agents causing citrus canker A, B, and C and other Xanthomonas genomes. Molecular genetics can now be employed to determine the role of these genes in plant-microbe interactions. The gained knowledge will be instrumental for improving citrus canker control.