Comparative genomic between the variant of Xanthomonas citri subsp. citri AT, that triggers a host-specific defense response, and the virulent reference strain.

ROESCHLIN R.A.; FAVARO M.A.; CHIESA M.A., ; CABRAL J.; D?ANDREA R.M.; YARYURA P.; VOJNOV A.; GADEA VACAS J.; FILIPPONE M.P.; ESTEBAN, L.; CASTAGNARO A.P.; MARANO M. R.

Rosario

Congreso; IX Reunión Anual de la Sociedad Argentina de Microbiología General (SAMIGE); 2013

SAMIGE

Citrus is an economically important fruit crop that is severely afflicted by Asiatic citrus bacterial canker (CBC), a disease caused by the phytopathogen Xanthomonas citri subsp. citri (X. citri). Recently, we characterized a new X. citri variant, named X. citri AT, which induces an atypical, non-cankerous chlorotic phenotype in Citrus limon and C. paradisi and weak cankerous lesions in C. aurantifolia and C. clementina leaves. In C. limon, the absence of typical CBC symptoms is concomitant with an oxidative burst, suggesting that bacterial factors would be involved in the suppression of CBC development and/or in triggering a hypersensitive-like response (HR) in host. For this reason, X. citri AT complete genome was sequenced by using 454/Roche platform. In the present work, the results of comparative genomics of this bacterium respect to the reference strain X. citri 306 are presented. Comparing both strains, we identified more than 300 different gene sequences related to virulence/pathogenicity, protein metabolism, lipid metabolism and stress response, among others. The sequence analyses of this new variant suggest that X. citri AT would express effector proteins which trigger an immune response in C. limon. Further characterization of different genes with a putative role in HR-like response will be important for the development of new strategies to manage the disease.