The influence of a polyamine oxidase inhibitor on the hydrogen peroxide defense system of Arabidopsis thaliana against Pseudomonas syringae

Bacterial infection by Pseudomonas syringae can cause leaf-spot and blast diseases that defoliate plants, leading to high loss in agricultural production. The aim of this project is to investigate the influence of polyamines and polyamine metabolism in Arabidopsis thaliana when subjected to Pseudomonas syringae infection. Because plants are sessile organisms they need to provide efficient defense against biotic and abiotic stresses. In order to protect themselves against pathogens plants have evolved several defense systems. Polyamines, such as spermidine and spermine, have multiple functions in plants, including growth, development, and defense against various environmental stressors, and these molecules play an important role during hypersensitive response triggered by pathogen attacks. During pathogen infection plants are able to degrade polyamines with the help of polyamine oxidases releasing hydrogen peroxide (H2O2) in order to destroy pathogenic microorganisms, such as Pseudomonas syringae. Plants were treated with guazatine in order to inhibit polyamine oxidases, and infiltrated with Pseudomonas syringae strain DC3000 afterwards. Bacterial growth is measured in guazatine treated and untreated groups to determine differences of plant defense. Furthermore, polyamine oxidase activity, H2O2 content, polyamine levels and gene(s) expression profiles were analyzed. In further research resulting from this project, different sections of possible H2O2 production pathways could be more narrowly defined.

My Experience

I had a great time exploring both the daily work of a researcher at BTI and the American culture. I met a lot of people from all over the world, improved my laboratory working skills and attended great events such as the annual BTI summer picnic. I also really enjoyed the weekly seminars with talks given from researchers of different scientific fields concerning plant research, and I was able to make new contacts which will be very helpful for my further career. I really appreciate the chance to participate in a summer internship in this beautiful town and all the priceless memories it gave to me!