INVESTIGADORES
ROSSI franco Ruben
congresos y reuniones científicas
Título:
POLYAMINE CATABOLISM IN THE PLANT PATHOGEN Pseudomonas syringae
Autor/es:
JUAN MANUEL VILAS; FRANCO RUBÉN ROSSI; OSCAR ADOLFO RUIZ; MARÍA MARINA; ANDRÉS GÁRRIZ
Lugar:
Mendoza
Reunión:
Congreso; Reunion Anual Sociedad Argentina de Investigación en Bioquímica y Biología Molecular; 2012
Resumen:
In bacteria, many mechanisms
regulate polyamine (PA) intracellular levels. The research conducted on this
subject has often been limited to biosynthesis and uptake rather than
catabolism. This work aimed to explore the PA catabolic pathways existing in
the plant pathogen Pseudomonas syringae. Putrescine and spermidine were
the most abundant PAs in this strain. In addition, bacteria were able to grow
in culture media amended with these compounds as nitrogen sources, proving the
existence of catabolic routes for them. In this trend, the analysis of the
bacterial genome identified four genes belonging to two different degradation
pathways in which PAs are oxidatively deaminated. qPCR performed on two of
these genes demonstrated the existence of a regulatory mechanism that reduces
their expression when putrescine is added to the culture medium. In turn, the
PA analogue 1,12-dodecanediamine, which inhibits PA oxidases from plants and
mice, blocked bacterial multiplication at 10 mM, suggesting that these enzymes
play a major role in the growth of the microorganism. However, the inhibitor
was unable to prevent the infection of Arabidopsis plants, even though it
should be kept in mind that this outcome may be due to a balance between the
inhibition of bacterial growth and the attenuation of host defense mediated by
plant PA oxidases previously reported by our group.