セミナー情報

Discovery of a novel plant strategy is essential to solve increasing global environmental issues. To that end, chromatin-based understanding is imperative as chromatin modification is widely connected to gene regulation in eukaryotes. Histone modification such as acetylation of lysine sites on histone N-terminus that is highly conserved epigenetic information in eukaryotes correlates with gene activity and formation of chromatin structure. Deacetylation of histone N-terminus by histone deacetylase is required for rapid gene repression, gene silencing in euchromatic region and maintenance in heterochromatic region. Suitable deacetylations drive adequate development, environmental response and chromatin reconstitution for survival, adaptation and evolution. However, only a few direct evidences have been found so far for chromatin regulation in plant stress responses.
　Arabidopsis histone deacetylase6 (HDA6) is involved in several biological events occurred on both euchromatin and heterochromatin regions in Arabidopsis. Recently, we found that HDA6 functions as a switch molecule of gene expression on euchromatin region to drive the metabolic flow conversion from glycolysis to acetic acid biosynthesis under drought stress. Moreover, this “acetic acid effect to confer the drought tolerance” is conserved in monocots and dicots. In contrast, on heterochromatin region, HDA6 represses the jumping of retro-transposable elements (TE) on genome wide and prevents the misamplification of Arabidopsis genome. In addition, HDA6 maintains higher order of heterochromatin on pericentromeric regions in Arabidopsis via these TE silencing. HDA6 extensively regulates Arabidopsis genome activity. In this seminar, I would like to discuss about HDA6 function as an epigenetic integrator of genome activity in Arabidopsis.