Participation of the AtPUT2 gene encoding a polyamine transporter in the plant defense response against Pseudomonas syringae

FLORES HERNÁNDEZ, E; GONZALEZ, ME; RODRÍGUEZ-KESSLER, M

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

The interaction between plants and microorganisms is recurrent in nature. Therefore, plants have developed a complex defense system that is activated just after pathogen recognition.The regulation of the plant defense system depends on several mediators, among which are polyamines. These amines are present in all organisms, where they are essential for cell viability. In plants, among other processes, polyamines participate in the establishment and regulation of the defense response, through modulating their metabolism, specifically their biosynthesis, conjugation, and catabolism. However, it is unknown whether polyamine transport is involved in the plant defense response. In our study, the importance of  Polyamine Uptake Transport 2 (AtPUT2) in the interaction between Arabidopsis thaliana and Pseudomonas syringae pv. tomato DC3000 was analyzed. We found that AtPUT2 expression is induced in response to P. syringae in the early stages of interaction. In turn, the absence of the transporter (in the Atput2-1 mutant line) induces Arabidopsis resistance to the bacterium. Under normal conditions and during interaction with the pathogen, the mutant line shows changes in the expression levels of genes involved in the salicylic acid pathway, suggesting that the resistance phenotype appears to be associated with the dysregulation of SA-mediated hormone signaling. Interestingly, using a reporter promoterline (promAtPUT2::GUS) it was found that AtPUT2 gene expression decreased in response to salicylic acid treatment. On the other hand, we found that the Atput2-1 mutant line does not adequately develop the hypersensitive response, an important process in the plantdefense response. However, the mechanism underlying this response remains to bedetermined. These results provide evidence for the involvement of the AtPUT2 transporter in the defense response of Arabidopsis against Pseudomonas syringae.