Arabidopsis thaliana heterochromatin and methylation dynamics

In Arabidopsis thaliana during embryogenesis and at the initial steps of seed germination the patterns of interphase chromatin organization are established with discrete heterochromatic regions, the chromocenters, associated with epigenetic modifications such as DNA methylation. Embryonic and early germination development endorses a developmental stress that promotes a reduction in heterochromatin levels, accompanied by decondensation of centromeric and pericentromeric domains, along whit a progressive dispersion of 5mC methylation signals. As the plant establishes the developmental stress decreases, and chromatin acquires a typical organization whit large chromocenters, compacted centromeric and pericentromeric sequence, co-located and well defined 5mC signals. DNA hypomethylation and the absence of light during germination results in a variation of chromatin dynamics associated with increased decondensation levels, which strongly sustain the crucial role of epigenetic in the establishment and dynamic of chromatin patterns organization.