Involvement of histone modification in regulating CUP-SHAPED COTYLEDON genes during shoot regeneration in Arabidopsis

Histone modification is a ubiquitous regulator of gene transcription. Arabidopsis CUP-SHAPED COTYLEDON ( CUC ) genes serve as a marker for shoot apical meristem initiation, but how they are regulated during shoot regeneration from in vitro culture, it is not yet understood. Here, the histone modification status of CUC1 , CUC2 , and CUC3 was analysed using a combination of chromatin immunoprecipitation (ChIP) and real time quantitative PCR. The activation of CUC1 and CUC2 was associated with an increased level of histone H3K4 trimethylation and/or H3K9 acetylation, as well as a reduced level of H3K9 demethylation in various parts of their promoter and coding sequences. Histone modification is suggested to play an important role in regulating CUC1 and CUC2 expression during shoot regeneration.