昼夜节律调控水稻杂种优势的比较转录组和表观基因组学研究

Rice is one of the most important food crop in our country and its heterosis has been widely used in agricultural production, but the mechanism is still unclear. Elucidating the molecular mechanism of heterosis in rice will help to further improve the food yield and new varieties. Present studies indicated that the core factors of circadian rhythm, including CCA1, TOC1 and GI, etc., have important regulatory functions in plant heterosis, and all these factors have been epigenetically modified, suggesting epigenetic regulation may play important roles in the circadian rhythm regulatory mechanism of rice heterosis. Based on our previous studies of comparative transcriptomics and small RNA-omics on the molecular mechanism of heterosis in hybrid rice, in this study we plan to use the flag leaves at grain-filling stage as materials for the comparative dynamic transcriptomics and epigenomics analysis of the super hybrid rice Liangyou2186 and its parents at different time points during circadian rhythms, by the next generation high-throughput sequencing technology, in order to analyze the circadian regulatory network of high yield heterosis in super hybrid rice, reveal the dynamic variations of gene expression, DNA methylation and histone modifications, and find the key regulatory factors and their regulation mechanisms, above of which will provide a theoretical basis for the breeding of new super-high-yield varieties of agricultural cultivation.

水稻是我国最重要的粮食作物之一，其杂种优势已在农业生产中广泛应用，但机理尚不十分清楚；阐明水稻杂种优势的分子机理有助于进一步提高水稻粮食产量和品种改良。目前研究表明，昼夜节律核心调控因子CCA1、TOC1、GI等在植物杂种优势中具有重要调控功能，而这些因子本身又受到表观遗传学修饰，暗示表观遗传学调控可能在水稻杂种优势的昼夜节律调控机制中发挥重要作用。在本实验室前期对水稻杂种优势分子机理的比较转录组学和小分子RNA组学研究基础上，本研究拟以水稻灌浆期剑叶为材料，通过新一代高通量测序技术，进行超级杂交稻两优2186与其父母本在昼夜节律多个时钟节点下的比较转录组和表观基因组动态研究，以期全面解析超级杂交稻高产杂种优势形成过程中的昼夜节律调控网络，揭示基因表达与DNA甲基化、组蛋白修饰的动态变化规律，发现其中的关键调控因子及其调控机理，为超高产农业新品种培育提供理论依据。