Arabidopsis chromatin alterations triggered by Pseudomonas syringae pv. tomato infection and their effects on defenses

ALVAREZ ME; CAMBIAGNO DAMIAN

Corrientes

Congreso; XXXI Reunión Argentina de Fisiología Vegetal; 2016

SAFV

Plant cells trigger many different alterations in response to microbial pathogen infection. At the nuclear level, they modify the patterns of gene expression, DNA methylation and histone methylation/ acetylation/phosphorylation regulating some defense genes through these epigenetic marks. In addition, they can manifest severe changes in chromatin structure under particular infection conditions. An example of this is the massive DNA demethylation (loss of 5-methyl cytosine) and heterochromatin relaxation that take place in Arabdiopsis cells infected with Pseudomonas syringae pv. tomato. These responses affect centromeric regions that are rich in repetitive sequences and transposons. This work evaluates how centromeric chromatin demethylation affects the expression of transposons and defense genes. To this end, we studied their behavior in two set of samples including infected wild type tissues and healthy tissues of mutant plants lacking centromeric repressive epigenetic marks. Our results suggest that deregulation of transposons influences the expression of disease resistance genes. Mechanisms that could generate this effect will be discussed.