Plant polyamine oxidases are differentially regulated during the Arabidopsis thaliana-Pseudomonas interaction

JASSO ROBLES, I; JIMÉNEZ-BREMONT, JF; GONZALEZ, ME; PIECKENSTAIN, FL; MÉNDEZ-IBERRI, A; RODRÍGUEZ-KESSLER, M

Querétaro

Congreso; XVI National Congress of Biochemistry and Plant Molecular Biology & IX Symposium México/USA; 2015

Polyamines (PAs) are small aliphatic amines with important regulatory activities in plant cells. The principal polyamines are putrescine, spermidine, spermine and thermospermine. The interest in studying the regulation of PAs through their catabolism is increasing, since the implications of PAs degradation in plant physiology and stress response is still elusive. PA catabolism is mediated by coper-dependent diamine oxidases (DAO) and flavin-dependent polyamine oxidases (PAO). The degradation products are aminoaldehydes, diaminopropane and hydrogen peroxide (H2O2). It has recently been proposed that H2O2 produced by PA catabolism participates in signaling mediated by PAs with multiple effects on defense, development and programmed cell death. Arabidopsis thaliana has five PAO enzymes. AtPAO1 and AtPAO5 are localized in the cytosol, while AtPAO2, AtPAO3 and AtPAO4 are located in the peroxisome. In this work we analyzed the role of A. thaliana AtPAO genes during the interaction with Pseudomonas syringae and P. viridiflava. qRT-PCR analysis show that the interaction with P. syringae up-regulates the expression of AtPAO1 and AtPAO2 while with P. viridiflava all AtPAO genes are down-regulated. The phenotype of T-DNA mutant insertional lines (single and double mutants of AtPAO1 and AtPAO2 genes) during the interaction with Pseudomonas species was also investigated. Preliminary data suggest that A. thaliana pao1-1xpao2-1 doble mutant is more susceptible to Pseudomonas infection than A. thaliana Col0. All this will allow us to understand how PAOs compartmentalization impacts in the production of H2O2, and its contribution to the defense against pathogens.