3’UTR来源的长链非编码RNA调控植物激素信号转导的机制研究

Non-coding RNAs (ncRNAs) play vital roles in growth and development of plants and animals as well as in occurrence and development of human diseases. Nowadays, exploring novel ncRNAs and dissecting their function are one of the hottest topics in biology. During our investigation of the signaling mechanism of plant hormone ethylene, we have found that long non-coding RNAs derived from 3’UTRs (3’lncRNAs) of EBF1/2 mRNAs modulates plant ethylene responses through promoting the translation of EBF1/2 genes. Furthermore, our finding reveals that the expressions of EBF1/2 genes are subjected to transcriptional activation and post-transcriptional regulation, both of which are most likely controlled by 3’lncRNA. Therefore, in the present proposal, we aim to investigate the molecular mechanisms of 3’lncRNA-directed regulation of EBF1/2 gene expression at translational, transcriptional and post-transcriptional levels. Meanwhile, we will systemically identify 3’lncRNAs in plant through genomic approaches, and explore their biological functions and mechanistic regulations on the transmission of genetic information in plants. Expected results of this proposal will potentially expand our understanding of ncRNAs.

非编码RNA在动植物生长发育和人类疾病发生等过程中具有重要调控作用，发掘新型的非编码RNA并探究其功能是当前生物学的研究热点。我们在研究植物气体激素乙烯作用机制时发现了一类来自mRNA 3’UTR的长链非编码RNA（3’UTR-derived long non-coding RNA，简称3’lncRNA），通过促进EBF1/2 mRNA的翻译来调控乙烯反应。此外，我们还发现EBF1/2 3’lncRNA有可能通过激活转录和产生内源siRNA的方式调控EBF1/2的基因表达。因此，本申请拟对EBF1/2 3’lncRNA从翻译、转录及转录后水平三个层面调控EBF1/2基因表达进行深入研究。同时，我们将利用基因组学方法系统分离和鉴定植物中的其它3’lncRNA，并对这一类新型lncRNA在植物基因信息传递过程中的调控机制和生理功能开展进一步研究，从而拓展我们对非编码RNA的认识。

长链非编码RNA（long non-coding RNA，即lncRNA）在生命活动中扮演着重要的角色。本项目负责人在研究植物激素乙烯信号转导时发现了一类来源于mRNA 3’UTR的长链非编码RNA分子（3’lncRNA）。这是一种新型的非编码RNA，但人们对其调控植物激素反应的作用机理仍然知之甚少。在本项目的资助下，通过研究：1）我们发现乙烯处理时3’lncRNAEBF1/2通过与PUBP1和EIN2直接相互作用而抑制EBF1/2的翻译；2）同时还发现3’lncRNAEBF1/2被RDR6与DCL2招募和加工形成siRNA进而以依赖AGO1的方式促进EBF1/2的转录；3）我们鉴定到了负责3’lncRNAEBF1/2产生的RNA内切酶NYN1；4）我们通过测定降解组而挖掘出大量新的3’lncRNA，进而挑选3’lncRNACO并对其生物学功能进行了验证，发现转基因植物明显晚花，这暗示3’lncRNA在植物中具有普适性；5）我们阐明了3’lncRNA来源的22 nt siRNA的合成通路，翻译抑制作用机理，并揭示了其在植物对环境胁迫适应性中的生物学意义。这些研究大大加深了我们对非编码RNA调控植物激素信号转导的理解，具有重要的意义。