Contribution of a harpin protein from Xanthomonas axonopodis pv. citri to pathogen virulence.

摘要: Summary Xanthomonas axonopodis pv. citri (Xac), the bacterium that causes citrus canker, contains a gene in hrp [for hypersensitive response (HR) and pathogenicity] cluster encodes harpin protein called Hpa1. Hpa1 produced HR nonhost plants tobacco, pepper Arabidopsis, whereas, host plant citrus, it elicited weak defence with no visible phenotype. Co-infiltrations of Xac or without recombinant leaves larger number cankers presence protein. To characterize effect during disease, an XacΔhpa1 mutant was constructed, infiltration this caused smaller cankers. In addition, lack hindered bacterial aggregation both solution in planta. Analysis infiltrated revealed alterations mesophyll morphology by cavitations crystal idioblasts, suggesting binding to membranes elicitation signalling cascades. Overall, these results suggest that, even though elicits and, lesser extent, plants, its main roles canker are alter leaf structure aggregate cells, thus increase virulence pathogen fitness. We expressed N-terminal C-terminal regions found although only region showed increased aggregation, supporting role as active domain.