State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangdong Laboratory for Lingnan Modern Agriculture, College of Life Sciences, South China Agricultural University, Guangzhou 510642, China.
Pain and Related Disease Research Laboratory, Shantou University Medical College, Shantou 515041, China.
Plant Physiol. 2024 Mar 29;194(4):2069-2085. doi: 10.1093/plphys/kiad568.
Organ size shapes plant architecture during rice (Oryza sativa) growth and development, affecting key factors influencing yield, such as plant height, leaf size, and seed size. Here, we report that the rice Enhancer of Zeste [E(z)] homolog SET DOMAIN GROUP 711 (OsSDG711) regulates organ size in rice. Knockout of OsSDG711 produced shorter plants with smaller leaves, thinner stems, and smaller grains. We demonstrate that OsSDG711 affects organ size by reducing cell length and width and increasing cell number in leaves, stems, and grains. The result of chromatin immunoprecipitation followed by deep sequencing (ChIP-seq) using an antitrimethylation of histone H3 lysine 27 (H3K27me3) antibody showed that the levels of H3K27me3 associated with cytokinin oxidase/dehydrogenase genes (OsCKXs) were lower in the OsSDG711 knockout line Ossdg711. ChIP-qPCR assays indicated that OsSDG711 regulates the expression of OsCKX genes through H3K27me3 histone modification. Importantly, we show that OsSDG711 directly binds to the promoters of these OsCKX genes. Furthermore, we measured significantly lower cytokinin contents in Ossdg711 plants than in wild-type plants. Overall, our results reveal an epigenetic mechanism based on OsSDG711-mediated modulation of H3K27me3 levels to regulate the expression of genes involved in the cytokinin metabolism pathway and control organ development in rice. OsSDG711 may be an untapped epigenetic resource for ideal plant type improvement.
器官大小在水稻（Oryza sativa）生长和发育过程中塑造植物结构，影响影响产量的关键因素，如株高、叶面积和种子大小。在这里，我们报告说，水稻 Enhancer of Zeste [E(z)] 同源物 SET DOMAIN GROUP 711（OsSDG711）调节水稻器官大小。OsSDG711 的敲除导致植株变矮，叶片变小，茎变细，籽粒变小。我们证明，OsSDG711 通过减少叶片、茎和籽粒中的细胞长度和宽度以及增加细胞数量来影响器官大小。使用抗组蛋白 H3 赖氨酸 27 三甲基化（H3K27me3）抗体的染色质免疫沉淀 followed by deep sequencing（ChIP-seq）的结果表明，OsSDG711 敲除系 Ossdg711 中与细胞分裂素氧化酶/脱氢酶基因（OsCKXs）相关的 H3K27me3 水平较低。ChIP-qPCR 分析表明，OsSDG711 通过 H3K27me3 组蛋白修饰调节 OsCKX 基因的表达。重要的是，我们表明 OsSDG711 直接结合这些 OsCKX 基因的启动子。此外，我们测量到 Ossdg711 植物中的细胞分裂素含量明显低于野生型植物。总的来说，我们的研究结果揭示了一种基于 OsSDG711 介导的 H3K27me3 水平调节参与细胞分裂素代谢途径的基因表达的表观遗传机制，并控制水稻器官发育。OsSDG711 可能是一种未被开发的表观遗传资源，可用于理想植物型改良。
