抽穗期是决定水稻地区和季节适应性的重要农艺性状。前期研究中，我们利用水稻晚熟突变体lvp1图位克隆了组蛋白甲基转移酶基因SDG724，验证了其编码蛋白的体内外酶学活性，并阐明了该酶通过影响OsMADS50和RFT1基因位点处染色质H3K36me2/3的甲基化水平调控水稻抽穗期，首次揭示了水稻抽穗期的表观遗传调控机制，该研结果已在国际学术期刊《Plant Cell》发表；同时，对lvp1突变体进行了化学诱变，获得了6个抽穗期显著提早的回复突变体，并已初步定位了其中1个突变基因。本项目在此基础上，拟采用高通量测序与图位克隆相结合的策略，克隆2-3个回复突变基因，并通过转基因遗传互补、遗传与基因表达分析以及染色质免疫共沉淀实验，研究突变基因的功能，探明它们与SDG724的互作关系及组蛋白甲基化所起的调控作用，以丰富水稻抽穗期的表观遗传调控机制，为水稻育种提供理论支撑和基因资源。

Rice heading date is an important agronomic trait for climatic and regional adaption. Previously, using a rice late flowering mutant lvp1, we cloned a histone methyl transferase gene SDG724 by map-based cloning, verified its enzymatic activity in vivo and in vitro, clarified it regulated rice heading date pathway by mediating histone H3K36me2/3 levels on Os MADS50 and RFT1 chromatin locis, revealed the epigenetic regulation mechanism of heading date in rice for the first time and published it in the international academic journal Plant Cell; meanwhile, 6 revertants were obtained by a chemical mutagenesis of lvp1, and 1 mutant gene was rough mapped. On this basis, this project intends to clone 2-3 reverse mutant genes by next generation sequencing technology combined with a map-based cloning strategy, and through genetic complementary, genetic and expression analysis, chromatin immunoprecipitation assay, understand the functions of these genes, prove the regulatory relationships between them and SDG724, clarify the roles of histone methylation in heading date regulation pathway, rich rice epigenetics mechanism of heading date, and provide theoretical support and genetic resources for rice breeding.