Characterization of plants with altered levels of PNPs in plant defense

FICARRA FA; GOTTIG N; OTTADO J

Rosario

Congreso; L Reunión Anual de la Sociedad Argentina de Investigación Bioquímica y Biología Molecular.; 2014

Xanthomonas axonopodis pv. citri, the citrus canker-causing pathogen, contains a gene encoding a plant natriuretic peptide (PNP)-like protein (XacPNP) that shares significant sequence similarity and identical domain organization with PNPs. It has been shown that XacPNP expression is induced upon infection of citrus plants, suggesting that this peptide is involved in plant-pathogen interaction. Moreover, XacPNP is able to improve host photosynthesis, rendering a healthier tissue that favors its own survival. We found that AtPNP from Arabidopsis thaliana is highly induced upon infection with Pseudomonas syringae pv. tomato. To characterize the effect of PNPs in plant infection, we obtained A. thaliana transgenic lines that overexpress XacPNP and AtPNP as well as knock out plants in its endogenous gene. Using a flooding assay we characterized the response of these modified A. thaliana lines to bacterial pathogens that are able to elicit different responses, such as disease and hypersensitive response. Our results indicated that the transgenic lines present altered responses to infection when compared to the parental line. Also, in planta pathogen growth experiments and the evaluation of the expression of genes related to plant defense showed differences among the transgenic lines bearing or not XacPNP and AtPNP, putting forward that PNPs have a role in plant pathogenesis and defense.