BIOFILM FORMATION DURING CITRUS CANKER REQUIRES THE Xanthomonas OUTER MEMBRANE PROTEIN OPRB

CAROLINA GRANDELLIS; FICARRA F; GOTTIG N; OTTADO J

Congreso; Congreso SAIB 2015; 2015

Citrus canker restricts citrus fruit export, and Xanthomonas citri subsp. citri (Xcc) is the causal agent of thisworldwide distributed disease. Previously, we detected that the expression of the outer membrane porin OprB isincreased during bacterial Xcc biofilm formation, OprB belongs to the family of carbohydrates transport proteins. Tofurther study its role during disease establishment, we constructed a Xcc deletion mutant (XccΔoprB) and confirmedthat this protein is required for the formation of biofilm structures, as well as for bacterial adherence to the plant cells,and also virulence. Furthermore, disease assays with both wild type and mutant pathogenic strains revealed adecrease of canker lesions by 50% when lacking OprB. Given the known function of OprB in other bacteria, glucoseuptake was measured and we demonstrated that OprB is necessary for glucose uptake to the cell. Moreover,metabolite abundance between the two strains was compared and differences of carbon intermediate metabolites weredetected revealing that Xcc undergoes a reprogramming of the carbon metabolism when it senses a shortage ofglucose input. Overall, our results point to the participation of OprB in the process of biofilm formation and virulencewith a main role in bacterial metabolic changes, highlighting that environmental nutrient availability may definepathogen virulence