Yao Yao, Zhou Jincong, Wang Jiacheng, Lei Xue, Jiang Anjie, Sun Qianwen
Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing, China.
Tsinghua-Peking Center for Life Sciences, Beijing, China.
Nat Plants. 2025 Apr;11(4):808-820. doi: 10.1038/s41477-025-01962-6. Epub 2025 Mar 31.
Eukaryotic euchromatin is the less-compact chromatin and is modified by many histone modifications such as H3 lysine 36 methylation (H3K36me). Here we report a new chromatin state, 'transcription resistive', which is differentiated from activation and silencing. Transcription resistive is stamped by H3K36me with almost undetectable transcription activity but open-chromatin state, and occupies most documented plant essential genes. Mutating SDG8, previously known as the major H3K36 methyltransferase in Arabidopsis, surprisingly elevates 78.7% of H3K36me3-marked resistive loci, which accounts for 39.4% of the coding genome. Genetically, SDG8 prevents H3K36me activity of SDG4 at short and intronless genes to secure plant fertility, while it collaborates with other H3K36me methyltransferases on long and intron-rich genes. Together, our results reveal that SDG8 is the primary sensor that suppresses excessive H3K36me, and uncovered that 'transcription resistive' is a conserved H3K36me-stamped novel transcription state in plants, highlighting the regulatory diversities and biological significance of H3K36 methylation in eukaryotes.
真核生物常染色质是结构较松散的染色质，会被多种组蛋白修饰所改变，如H3赖氨酸36甲基化（H3K36me）。在此我们报告一种新的染色质状态——“转录抗性”，它与激活和沉默状态不同。转录抗性以H3K36me为特征，转录活性几乎检测不到，但染色质处于开放状态，且占据了大多数已记录的植物必需基因。突变之前被认为是拟南芥中主要H3K36甲基转移酶的SDG8，令人惊讶地使78.7%的H3K36me3标记的抗性位点增加，这些位点占编码基因组的39.4%。在遗传学上，SDG8在短的无内含子基因上阻止SDG4的H3K36me活性以确保植物育性，而在长的富含内含子的基因上它与其他H3K36me甲基转移酶协作。总之，我们的结果表明SDG8是抑制过量H3K36me的主要感知器，并揭示“转录抗性”是植物中一种保守的由H3K36me标记的新转录状态，突出了真核生物中H3K36甲基化的调控多样性和生物学意义。
