Unraveling epigenetic changes in A. thaliana calli: Impact of HDAC inhibitors

The aim was to characterize epigenetic changes in histone proteins during callus formation from roots and shoots of Arabidopsis thaliana seedlings using mass spectrometry-based approach. Increased level of histone H3.3 variant was found to be the most prominent feature of 20-day-old calli, associated with chromatin relaxation. Methylation status in root- and shoot-derived calli reached the same level during long-term propagation, whereas differences in acetylation levels provided a long-lasting imprint of root and shoot origin. On the other hand, epigenetic signs of origin completely disappeared during 20 days of calli propagation in the presence of histone deacetylase inhibitors (HDACi), sodium butyrate and trichostatin A, although each HDACi affected the state of post-translational histone modifications in a specific manner.