Modulation of polyamine metabolism in Arabidopsis thaliana by salicylic acid

ROSSI, FRANCO; GARRIZ, ANDRES; MARINA, MARÍA; PIECKENSTAIN, FERNANDO

PHYSIOLOGIA PLANTARUM

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2021 vol. 173 p. 843 - 855

0031-9317

Polyamines(PAs) play important roles in plant defense against pathogens, but theregulation of PA metabolism by hormone-mediated defense signaling pathways hasnot been studied in depth. In this study, the modulation of PA metabolism inArabidopsis by salicylic acid (SA) was analyzed, by combining the exogenousapplication of this hormone with the use of PA biosynthesis and SAsynthesis/signaling mutants. SA induced notable modifications of polyaminemetabolism, mainlyconsisting in putrescine accumulation both in whole-plant extracts andapoplastic fluids. Put was accumulated at the expense of increased biosynthesisby arginine decarboxylase 2 and decreased oxidation by copper amine oxidase.Enhancement of Put levels by SA was independent of the regulatory protein Non-Expressor of Pathogenesis Related 1(NPR1) and the signaling kinases MKK4 and MPK3, but depended on MPK6. On itspart, plant infection by Pseudomonassyringae pv. tomato DC3000elicited Put accumulation in a SA-dependent way. The present study demonstratesa clear connection between SA signaling and plant PA metabolism in Arabidopsis andcontributes to understand the mechanisms by which SA modulates PA levels duringplant-pathogen interactions.