真核生物存在大量长度大于200核苷酸但不编码蛋白的RNA分子，即lncRNA。研究表明，人类和动物细胞的lncRNA通过顺式或反式作用对编码基因进行调控。然而，lncRNA在植物中的研究非常滞后，有限的报道仅围绕拟南芥和水稻开展。二穗短柄草是近年来发现的研究禾谷类作物和能源植物的模式生物，但人们对其非编码RNA缺乏了解，对其lncRNA无任何研究。我们前期研究结果揭示了短柄草中由miRNA和选择性剪切介导成花素FT基因转录后水平调控的分子机制，并进一步发现FT2 内含子区可产生lncRNA，命名为LNR2。有意思的是，尽管不同光照时间条件下FT2表达存在明显差异，但LNR2表达并无明显不同；过量表达LNRFI2的转基因植株开花显著延迟。本项目将以此为出发点，深入研究LNR2参与光周期开花过程的生物学功能和作用机理。本项目将为深入了解lncRNA调控植物基因表达的分子机制提供重要启示。

There is now accumulating evidence that long non-coding RNAs (>200 nucleotides) called lncRNAs are widely spread in eukaryotic genomes. Many lncRNAs characterized from animal and human cells have been demonstrated that they epigenetically or post- transcriptionally regulate protein-coding mRNAs in cis or in trans. However, the progress of lncRNA investigation in plants is quite limited and some initial studies reported have been only focused on Arabidopsis and rice. There is no any functional exploration of lncRNAs to date in Brachypodium distachyon which has been extensively thought as a suitable model system for studies on temperate cereals and biofuel plants. Previously, we revealed the mechanisms of post-transcriptional regulation of florigen genes (FLOWERING LOCUS T 1 and 2, FT1 and FT2) mediated by microRNAs (miRNA) and alternative splicing (AS) in flowering time control in Brachypodium. We subsequently identified a lncRNA namely LONG NON-CODING RNA FROM FT2 INTRON 2 (LNR2) from the intronic region of FT2, and interestingly found it had different expression patterns with FT2 under long-day and short-day environments. Overexpression of LNR2 transgenic plants severely delay the heading date. In this project, integrated with genetics, biochemistry and molecular biology approaches, we will pursue the role and action mechanisms of LNR2 in photoperiod-mediated flowering time control in Brachypodium. The information obtained in this study will not only provide novel insights into mechanisms of gene modulation by lncRNAs in plants, but also may develop new technologies for molecular improvement on crop heading date in the future.