IBR   13079
INSTITUTO DE BIOLOGIA MOLECULAR Y CELULAR DE ROSARIO
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Analysis of a Xanthomonas axonopodis pv. citri Hairpin in Host and Non-Host Plants
Autor/es:
SGRO GG; DUNGER G; ORELLANO EG; OTTADO J; GOTTIG N
Lugar:
Tucumán, Argentina
Reunión:
Congreso; XLV Reunión Anual de la Sociedad Argentina de Investigación en Bioquímica y Biología Molecular; 2009
Institución organizadora:
XLV Reunión Anual de la Sociedad Argentina de Investigación en Bioquímica y Biología Molecular.
Resumen:
Plant-pathogenic bacteria colonize their hosts through the secretion of virulence effector proteins by the type III protein secretion system. This system is codified by the hrp (for hypersensitive response (HR) and pathogenicity) cluster and it is indispensable for pathogenicity in the host plant and induction of HR since it mediates the translocation of effector proteins across the bacterial membrane and the walls and plasma membranes of plant cells. HR is a rapid, local, programmed cell death that is induced upon recognition of the pathogen and inhibits pathogen growth within the infected plants. Xanthomonas axonopodis pv. citri (Xac) hrp cluster has a hpa1 gene that encodes a harpin. Harpins are heat-stable, glycine-rich proteins that associate stably with synthetic membranes and form ion-conducting pores. We constructed a Xac hpa1 deletion mutant and analyzed the role of Hpa1 in citrus canker as well as its capacity as an HR inducing peptide in non-host tobacco plants. Although we observed that Hpa1 could induce HR in non-host plants, elicitation of HR in citrus leaves by this harpin depends also on the presence of other bacterial determinants. These joined actions enhance basal immune responses and resembles pathogen-associated molecular pattern (PAMP)-triggered immunity, suggesting a role for Hpa1 as a PAMP.