IBR   13079
INSTITUTO DE BIOLOGIA MOLECULAR Y CELULAR DE ROSARIO
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
STUDY OF XACPNP IN XANTHOMONAS CITRI SUBSP. CITRI
Autor/es:
MARÍA VICTORIA BARCAROLO, BETIANA S. GARAVAGLIA, FLORENCIA A. FICARRA, NATALIA GOTTIG, JORGELINA OTTADO
Lugar:
Bogotá
Reunión:
Conferencia; 5th Xanthomonas Genomics Conference; 2015
Resumen:
Xanthomonas citri subsp. citri (Xcc) is the bacterium responsible for citrus canker. This phytopathogen contains a gene encoding a plant natriuretic peptide (PNP)-like protein (XacPNP) that shares significant sequence similarity and identical domain organization with PNPs and it is not present in any other bacteria. PNPs are peptide hormones involved in regulation of ions and water homeostasis. We have previously shown that XacPNP is involved in plant-pathogen interaction modulating host homeostasis to the benefit of the pathogen, such as the improvement of host photosynthesis, rendering a healthier tissue that favors the survival of this biotrophic bacterium. However, a possible role of XacPNP on bacterial physiology has never been studied. XacPNP is synthesized as a preprotein and probably processed during secretion. We found that expression of the recombinant XacPNP precursor caused bacterial lysis in Esherichia coli, and this effect was not observed when the predicted mature protein was expressed. Moreover, the expression of XacPNP precursor in Xcc, and in a variant of Xanthomonas axonopodis pv. vesicatoria, impaired bacterial survival of both strains under saline stress conditions. These results suggest a possible role of XacPNP in the regulation of ion influx in these bacteria. The infiltration of a Xcc strain that expresses XacPNP fused to GFP in citrus leaves revealed that this protein is secreted as predicted by bioinformatics and localizes on the citrus cells plasma membrane. These results suggest that XacPNP is secreted to exert its function and that it has an effect on bacterial physiology in saline environmental conditions.