The Arabidopsis genome displays centromeric DNA hypomethylation and cytological alterations of heterochromatin upon the attack by virulent Pseudomonas

PAVET V; QUINTERO C; CECCHINI N; ROSA AL; ALVAREZ ME

AMER PHYTOPATHOLOGICAL SOC

Año: 2006 vol. 19 p. 577 - 577

lant tissues display major alterations upon the perception of microbial pathogens. Changes of cytoplasmic and apoplastic components that sense and transduce plant defenses have been extensively characterized. In contrast, less information is available about modifications affecting the plant nuclear genome under these circumstances. Here, we investigated whether the Arabidopsis thaliana DNA methylation status is altered in tissues responding to the attack of Pseudomonas syringae pv. tomato DC3000. We applied amplified fragment length polymorphism analysis to monitor cytosine methylation at anonymous 5′-CCGG-3′ and 5′- GATC-3′ sites in naïve and infected samples. Plant genomic fragments reducing methylation upon infection, including peri/centromeric repeats such as the 180-bp unit, Athila retrotansposon, and a portion of the nuclear insertion of mitochondrial DNA, were isolated and characterized. P. syringae pv. tomato-induced hypomethylation was