Transcriptional profiling of Arabidopsis polyamine oxidase 1 mutant and overexpression line in interaction with Pseudomonas syringae

GONZÁLEZ-PÉREZ, E; JASSO ROBLES, FI; GONZALEZ, ME; JIMÉNEZ-BREMONT, JF; OVANDO-VÁZQUEZ, C; BECERRA-FLORA, A; DE DIEGO, N; RODRÍGUEZ-KESSLER, M

Oaxaca

Congreso; XX National Plant Biochemistry and Molecular Biology Congress, 3rd Meeting of the Mexico Section of the American Society of Plant Biologists, 13th Mexico-USA Plant Biology Symposium; 2023

Polyamine catabolism by polyamine oxidase enzymes mediates signaling and stress responses through hydrogen peroxide production. Five genes encode polyamine oxidasesin the Arabidopsis thaliana genome, with cytoplasmic and peroxisomal localization.Recently, we analyzed the phenotype of Atpao single mutants in response to Pseudomonas syringae pv. tomato DC3000 and identified that the Atpao1-1 single mutant was resistant to bacterial infection. This mutant line has lower spermine oxidation activity, accumulates reactive oxygen species (hydrogen peroxide and superoxide anion radical), and shows increased RBOH activity and alterations in the activity of different antioxidant enzymes. In addition, several markers of the salicylic acid pathway were found to be deregulated in the mutant line in comparison to the WT (A. thaliana ecotype Columbia). All these data suggested that cytoplasmic polyamine oxidation through AtPAO1 impacts hydrogen peroxide production and hormonal signaling. To further understand the participation of the AtPAO1 gene in plant defense the Atpao1-1 mutant and a 35S::AtPAO1 overexpression line were sequenced by RNAseq. Herein, we present an analysis of the Atpao1-1 mutantand 35S::AtPAO1 transcriptomes under control and stress conditions (24 hpi with P. syringae). In the WT, biological processes such as the jasmonic acid mediated signaling pathway, plant-type hypersensitive response, glutathione metabolic process, and responset o hydrogen peroxide, were up-regulated in response to the pathogen while in the Atpao1-1 mutant, these processes were down-regulated 24 hpi. In accordance with previous observations, the ethylene synthesis and signaling pathway was repressed in the Atpao1-1mutant line in control and stress conditions. Furthermore, the auxin and cytokinin signaling pathways were deregulated in the mutant Atpao1-1 mutant and a 35S::AtPAO1. The participation of polyamine oxidation in plant defense and in the modulation of hormonal response in discussed.