Characterization of a new Xanthomonas citri subsp.citri isolate which triggers a host-specific response

ROESCHLIN R.A.; CHIESA M.A; ENRIQUE R.; FAVARO M.A; TORRES P.S.; FILIPPONE M.P.; GMITTER JR. F.; VOJNOV A.A.; CASTAGNARO A.; MARANO M.R.; .GADEA J

valencia

Congreso; xii iNTERNATIONAL cITRUS cONGRESS; 2012

Citrus is an economically important fruit crop that is severely afflicted by Asiatic citrus bacterial canker (CBC), a disease caused by Xanthomonas citri subsp. citri (XC). Recently, we have identified a XC strain, named XCT44, which induces a hypersensitive-like response in Citrus limon leaves. To gain insight into the dynamics of these host-specific responses, we have investigated biofilm formation and accumulation of defense markers by XCT44 on different citrus species. Biofilm formation was monitored by confocal laser scanning microscopy (CLSM) over a 10-day period. XCT44 strain was unable to form structured biofilm after 6 days post-inoculation. This observation is associated with early production of reactive oxygen species by the plant. Transcriptomic analysis of C. limon leaves in response to the non pathogenic (XCT44) and pathogenic (XC) strains showed that XCT44 induces specific genes that points towards the involvement of salicylic acid and glucosinolates metabolism in the onset of the defense responses. Further characterization of these genes with a role in this HR-like response will be important for the development of new strategies to manage the disease.