Zheng Beibei, Liu Jingjing, Gao Anqi, Chen Xiaomei, Gao Lingling, Liao Liao, Luo Binwen, Ogutu Collins Otieno, Han Yuepeng
CAS Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, The Innovative Academy of Seed Design of Chinese Academy of Sciences, Wuhan 430074, China.
Hortic Res. 2022 Jun 3;9:uhac132. doi: 10.1093/hr/uhac132. eCollection 2022.
Plant tissues are capable of developing unorganized cell masses termed calluses in response to the appropriate combination of auxin and cytokinin. Revealing the potential epigenetic mechanisms involved in callus development can improve our understanding of the regeneration process of plant cells, which will be beneficial for overcoming regeneration recalcitrance in peach. In this study, we report on single-base resolution mapping of DNA methylation and reprogramming of the pattern of trimethylation of histone H3 at lysine 27 (H3K27me3) at the genome-wide level during the leaf-to-callus transition in peach. Overall, mCG and mCHH were predominant at the genome-wide level and mCG was predominant in genic regions. H3K27me3 deposition was mainly detected in the gene body and at the TSS site, and GAGA repetitive sequences were prone to recruit H3K27me3 modification. H3K27me3 methylation was negatively correlated with gene expression. culture of leaf explants was accompanied by DNA hypomethylation and H3K27me3 demethylation, which could activate auxin- and cytokinin-related regulators to induce callus development. The DNA methylation inhibitor 5-azacytidine could significantly increase callus development, while the H3K27me3 demethylase inhibitor GSK-J4 dramatically reduced callus development. These results demonstrate the roles of DNA methylation and H3K27me3 modification in mediating chromatin status during callus development. Our study provides new insights into the epigenetic mechanisms through which differentiated cells acquire proliferative competence to induce callus development in plants.
植物组织能够在生长素和细胞分裂素的适当组合作用下，发育形成称为愈伤组织的无组织细胞团。揭示愈伤组织发育过程中潜在的表观遗传机制，有助于我们更好地理解植物细胞的再生过程，这将有利于克服桃的再生难问题。在本研究中，我们报告了桃从叶片到愈伤组织转变过程中，全基因组水平上DNA甲基化的单碱基分辨率图谱以及组蛋白H3赖氨酸27位点三甲基化（H3K27me3）模式的重编程。总体而言，mCG和mCHH在全基因组水平上占主导地位，而mCG在基因区域占主导地位。H3K27me3沉积主要在基因体和转录起始位点（TSS）检测到，并且GAGA重复序列易于招募H3K27me3修饰。H3K27me3甲基化与基因表达呈负相关。叶片外植体培养伴随着DNA低甲基化和H3K27me3去甲基化，这可以激活生长素和细胞分裂素相关调节因子以诱导愈伤组织发育。DNA甲基化抑制剂5-氮杂胞苷可显著促进愈伤组织发育，而H3K27me3去甲基化酶抑制剂GSK-J4则显著降低愈伤组织发育。这些结果证明了DNA甲基化和H3K27me3修饰在愈伤组织发育过程中介导染色质状态的作用。我们的研究为分化细胞获得增殖能力以诱导植物愈伤组织发育的表观遗传机制提供了新的见解。
