Polyamines and poliaminooxidases in plant defense against pathogenic microorganisms

MARINA M; GONZALEZ ME; ROSSI FR; ROMERO FM; MAIALE SJ; GÁRRIZ A; RUIZ OA; PIECKENSTAIN FL

Mendoza

Congreso; XLVIII Reunión Anual Sociedad Argentina de Investigación en Bioquímica y Biología Molecular; 2012

Polyamines, natural polycationic compounds essential for all living organisms, are involved in a variety of physiological processes. Polyamines are positively charged at physiological pH, thusinteracting with negatively charged macromolecules such as nucleic acids and proteins. Plant polyamine melabolism is affected by a number of stresses, including pathogen infection. Recently, the use of model plants such as Nicotiana tabacum and Arabidopsis thaliana, as well as novel inhibitors of polyaminc catabolism, increased our knowledge on the role of PAs in plant defense.Diamino and polyaminooxidases, which metabolize polyamines and release hydrogen peroxide, were shown to contribute to tobacco resistance to pathogenic bacteria, fungí and viruses.Modifications of plant spermine levels by different experimental approaches demonstrated that this tetraamine contributes to A. thaliana resistance to the biotrophic bacterium Pseudomonas viridiflava and cucumber mosaic virus. Interestingly, in planta spermine accumulation led to a variety of transcriptional changes related to plant defense. Further elucidation of PA-mediated changes in the expression of defense-related genes represents an interesting challenge for molecular plant pathologists.