近日，华中农业大学作物遗传改良国家重点实验室周道绣课题组取得重要研究成果，5月8日，相关研究成果在学术期刊《植物细胞》（Plant Cell）上发表。

该研究利用高通量测序探究了水稻幼穗形成过程中组蛋白H3赖氨酸27（H3K27）和赖氨酸27 （H3K4）甲基化和基因表达的动态变化，发现这两种不同的组蛋白赖氨酸甲基化的相对变化对幼穗形成过程中基因表达重编程起重要的作用。抑制或超量表达相关的组蛋白赖氨酸甲基化酶和去甲基化酶不仅影响水稻穗发育过程中全基因组水平上组蛋白甲基化变化和一些关键性穗发育调控基因的表达水平，同时也改变了穗形和穗粒数。

进一步的研究表明上述组蛋白赖氨酸甲基化酶和去甲基化酶相互作用，控制一系列重要基因表达在幼穗发育过程中的重编程。这些结果部分揭示了水稻幼穗发育基因表达的表观调控机制。（来源：中国科学报 赵毓 文乐乐）

Regulation of Histone Methylation and Reprogramming of Gene Expression in the Rice Inflorescence Meristem

Abstract  Rice inflorescence meristem (IM) activity is essential for panicle development and grain production. How chromatin and epigenetic mechanisms regulate IM activity remains unclear. Genome-wide analysis revealed that in addition to genes involved in the vegetative to reproductive transition, many metabolic and protein synthetic genes were activated in IM compared with shoot apical meristem and that a change in the H3K27me3/H3K4me3 ratio was an important factor for the differential expression of many genes. Thousands of genes gained or lost H3K27me3 in IM, and downregulation of the H3K27 methyltransferase gene SET DOMAIN GROUP 711 (SDG711) or mutation of the H3K4 demethylase gene JMJ703 eliminated the increase of H3K27me3 in many genes. SDG711-mediated H3K27me3 repressed several important genes involved in IM activity and many genes that are silent in the IM but activated during floral organogenesis or other developmental stages. SDG711 overexpression augmented IM activity and increased panicle size; suppression of SDG711 by RNA interference had the opposite effect. Double knockdown/knockout of SDG711 and JMJ703 further reduced panicle size. These results suggest that SDG711 and JMJ703 have agonistic functions in reprogramming the H3K27me3/H3K4me3 ratio and modulating gene expression in the IM.

原文链接：http://www.plantcell.org/content/early/2015/05/08/tpc.15.00201.full.pdf+html