Mechanisms of infection used by Xanthomonas axonopodis pv. citri in citrus canker disease

GOTTIG N; GARAVAGLIA BS; GAROFALO CG; ZIMARO T; SGRO GG; FICARRA FA; DUNGER G; DAURELIO LD; THOMAS L; GEHRING C; ORELLANO EG; OTTADO J

Current Research, Technology and Education Topics in Applied Microbiology and Microbial Biotechnology

FORMATEX

Lugar: Badajoz, España; Año: 2010;

The citrus canker causing bacteria Xanthomonas axonopodis pv. citri uses several mechanisms to colonize its host. Among them, attachment to the host surface by specific proteins named adhesins is important to the progress of the disease. Once the bacteria is attached to the host it delivers pathogenicity effector proteins inside the plant cell trough the type III protein secretion system that modulate the plant basal defense response for the benefit of the pathogen. As a later step in pathogenesis, X. axonopodis pv. citri must form biofilms which are matrix-enclosed bacterial populations that adhere to each other with the involving of adhesins and the exopolysaccharide xanthan. Besides these basic mechanisms this bacteria uses also a plant natriuretic peptide-like protein to regulate host homeostasis and in that way improves host photosynthesis leading to a more healthy tissue during the infection that suit X. axonopodis pv. citri biotrophic lifestyle. These bacterial strategies in citrus canker are discussed.