Polyamine concentrations are dynamically regulated during plant-Pseudomonas syringae interactions

FRANCO RUBÉN ROSSI; JUAN MANUEL VILAS; FERNANDO MATÍAS ROMERO; OSCAR ADOLFO RUIZ; ANDRÉS GÁRRIZ

Congreso; Reunion conjunda de sociedades de biociencias; 2017

AbstractDue to their abilities to bind polyanions such as nucleic acids andproteins, the polyamines putrescine, spermidine and spermine are involved in several cellularresponses. For instance, these amines participate in the activation of plantdefense responses and are required for virulence of plant pathogens. Thus, themodulation of their metabolism plays essential roles in plant-pathogeninteractions. In this work, we challenged plants with different pathovars of the bacteria Pseudomonassyringae to evaluate the changes in theconcentrations of polyamines occurring in contrasting pathogenic interactions.Our analysis demonstrated that polyamines are increased in tomato in responseto a virulent strain, which was associated to the induction of severalpolyamine metabolic genes from the plant and the bacteria. These resultssuggest that the metabolism of both organisms modulates polyamine contents ininfected tissues. Interestingly, the rise in the concentration of putrescine was particularly higher in apoplastic fluids. A further exploration ofthe polyamine profiles using Arabidopsis plants demonstrated thatnon-pathogenic strains inducing the hypersensitive response provoked aremarkable increment in their concentrations, which was not observed by usingan avirulent non-host bacteria. Thus, specificregulatory mechanisms may modulate polyamine metabolism in different biologicalinteractions.