二穗短柄草基因间区增强子鉴定及其组蛋白修饰特征分析

Enhancers are essential elements that involved in gene regulation. Genome-wide identification and functional characterization of plant enhancers will not only provide insight into the mechanism of the gene regulation, but also facilitate the application of enhancers in plant genetic engineering. Wheat is one of the three most important food crops in China. Because of its huge genome size and large number of repeats, wheat functional genomic study and breeding have been daunting tasks. Thus, the exploit and investigation of wheat relatives, such as Brachypodium distachyon, can expedite our understanding of both fundamental and applied genetics in wheat. This proposal aims to identify intergenic enhancers in B. distachyon on a genome-wide scale using DNase-seq. Subsequently, the function of candidate enhancers will be validated using permanent transformation or transient expression assay. In addition, with multiple genomic approaches including mRNA-seq and ChIP-seq, the relationship among enhancers, their associated histone modifications and nearby gene expression will be comprehensively investigated and discussed. The outcome of this project will not only strengthen our understanding on how gene expression is coordinated by enhancers and histone modifications, but also it will provide candidate enhancers in wheat genetic engineering and molecular breeding.

增强子是基因表达调控的重要元件之一。植物全基因组增强子的鉴定及功能分析，不仅有利于加强对基因表达调控机制的理解，同时可为植物基因工程中增强子的应用提供重要的理论依据。小麦是我国三大粮食作物之一，但其基因组庞大，重复序列繁多，导致对小麦功能基因组的研究进展相对缓慢，分子育种也面临巨大的挑战。 因此，对近缘模式植物基因表达调控的探索有利于加速小麦理论研究及基因工程育种。本项目采用DNase-seq、mRNA-seq和ChIP-seq等组学手段在全基因组水平鉴定二穗短柄草幼苗期基因间区增强子，全面分析增强子及邻近基因表达水平的内在联系；探讨增强子周围核小体的组蛋白修饰特征与增强子功能的关系；最后，选取部分增强子进行转基因或瞬时转化功能验证。该研究成果将加强我们对增强子在基因表达调控中作用机制的认识，深化对增强子周围核小体组蛋白修饰特征的理解，同时也为小麦基因工程中增强子的选择与应用奠定理论基础。