Large-scale chromatin de-compaction induced by low light is not accompanied by nucleosomal displacement.

Arabidopsis thaliana is widely used as model to study chromatin compaction dynamics during development and in response to the environment. Signals such as prolonged heat treatment, low light and pathogen infestation are known to induce large-scale de-condensation of nuclear chromatin. Here we demonstrate that the response to different environments varies at the nucleosomal level. Our results show that in contrast to previous reports on heat and biotic infestation, low light intensity signaling does not alter nucleosomal occupancy, despite the marked effects of low light on global chromatin compaction.