OsMADS27在microRNA444b介导下调控水稻种子萌发的机理探讨

项目名称： OsMADS27在microRNA444b介导下调控水稻种子萌发的机理探讨

项目编号： No.31470288

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 生物科学

项目作者： 吴凤

作者单位： 中国科学院植物研究所

项目金额： 85万元

中文摘要： 种子萌发作为作物生长并保证产量的关键环节,受众多内外因素（尤其是激素）的复杂调控。双子叶植物拟南芥中已鉴定到一系列参与种子萌发的因子，而且形成了一个主要的调控网络。然而，在作为重要农作物的单子叶植物水稻中，种子萌发的分子机理和调控网络还有待完善。本项目的实验材料是前期工作中得到的一个水稻OsMADS27基因的功能缺失突变体，表现为种子萌发延迟，而且该表型能够很好的被OsMADS27的全长基因组序列所互补。检测发现突变体中ABA含量明显升高。此外，序列分析发现OsMADS27基因是microRNA444b的靶基因之一。本项目的申请旨在探讨OsMADS27基因如何与microRNA444b相互作用通过影响ABA等种子萌发相关激素的含量，进而影响种子萌发的分子机理。本研究的开展将丰富现有受microRNA调控的MADS基因的功能研究，为水稻种子萌发调控网络的整合提供一些科学证据。

中文关键词： 水稻；MADS-box基因；种子萌发；小RNA；脱落酸

英文摘要： Seed germination is a thread of life of plants that guarantee its survival, thus playing an important role in modern agriculture to increase crop production to feed the growing world population. It is known that seed germination is usually regulated by a series of internal and external factors, especially plant hormones. In the eudicot model plant Arabidopsis, many such seed germination-related factors have been identified, and a relatively clear understanding of germination regulatory networks has been established. However, in monocots such as rice, the function of MADS-box genes involved in the seed germination is still unknown, and the further molecular mechanisms that control germination still need to be elucidated. In this study, we obtained an OsMADS27 loss-of-function mutant of rice and observed delayed germination and increased ABA content phenotypes. This delayed germination could be rescued by expression of OsMADS27, but the precise functional role of this factor remains unknown and requires further investigation. In addition, previous sequence analysis showed that OsMADS27 is one of the target genes of microRNA444b, though there is no direct molecular or functional evidence for this. Therefore, here we also seek to investigate the regulatory roles of miR444b-regulated OsMADS27 inhibiting ABA synthesis in regulating seed germination in rice. This study will help us to better understand the functions of MADS-box genes that are regulated by microRNA, and will supply some direct evidence that demonstrates the integration of multiple regulatory networks of seed germination in rice.

英文关键词： rice;MADS-box gene;seed germination;microRNA;ABA