Exogenous Salicylic Acid Induce Changes in Putrescine Metabolism in A. thaliana

ROSSI, FRANCO RUBÉN; MARINA, MARÍA; PIECKENSTAIN, FERNANDO LUIS

Rosario

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

Sociedad Argentina de Investigaciones en Bioquímica y Biología Molecular

Salicylic acid (SA) is a key hormone for defense responses in plants, and plays a critical role in resistance to pathogens. Increments on SA levels activate different signaling cascades in which that defense hormone participates, where H2O2 acts as a secondary messenger and activates a large number of mechanisms that contribute to overall plant defense. On the other hand, polyamines are a group of compounds that are active in defense mechanisms against pathogens. The metabolism of the diamine putrescine (Put) is altered by stressful conditions in plants, which generally results increasing its levels. Previous results showed that exogenous addition of SA induces a high increase in Put levelsmediated by an increase in ADC2 activity . Moreover, in apoplastic fluid, Put levels were increased and amine oxidase activity was decreased in plants treated with exogenous SA. The staining with diaminebenzidine to adc2 mutant plants(with had lower levels of Put than WT plants), allowed noting that these plants accumulate higher levels of H2O2 than WT plants after SA addition. Put supplementation to adc2 mutant plants decreased the H2O2 levels. These results indicate that the accumulation of Put, after the exogenous addition of SA, it is probably necessary to regulate H2O2 levels during plant defense responses.