受茉莉酸诱导的FtERF5转录因子调控苦荞抗倒伏的分子机制研究

Tartary buckwheat (Fagopyrum tataricum) is a crop suitable for medicine and food due to containing various flavonoids, minerals, and vitamins etc. Lodging limits buckwheat yields, but the molecular mechanism of lodging resistance remains unclear. It has been reported that lignin content is closely related to lodging resistance. Previously, we found that methyl jassonate (MeJA) induced semidwarf growth in buckwheat and increased the content of lignin. We identified the AP2-ERF (APETALA2/Ethylene Responsive Factor) type transcription factor FtERF5 was highly increased with MeJA treatment and co-expressed with lignin synthesized related genes by transcriptome sequencing. In this study, we will combine various techniques including molecular biology, biochemistry and cell biology to investigate the expression pattern of FtERF5, to identify the targeting lignin synthesized gene, to identify interacting factors, and to demonstrate the function of FtERF5 in buckwheat. This study will deeply explain the molecular mechanism of MeJA signaling-mediated lodging resistance mediated by FtERF5, and provide theoretical basis for buckwheat molecular breeding of lodging resistance.

苦荞富含多种黄酮类物质、矿物质、维生素等，是一种药食两用的经济作物。倒伏是影响苦荞产量的重要农艺性状，但是苦荞抗倒伏的分子调控机制尚不清楚。大量研究证明，木质素含量与作物倒伏密切相关。本研究前期工作发现外源施加茉莉酸甲酯促进苦荞半矮化生长，木质素含量增加。利用转录组测序筛选到受茉莉酸甲酯诱导并与木质素合成相关基因高度关联的AP2/ERF（APETALA2/Ethylene Responsive Factor）类转录因子FtERF5。本项目拟在此基础上利用qRT-PCR、凝胶迁移、酵母单杂交、酵母双杂交等分子生物学、生物化学及细胞生物学等技术手段，分析FtERF5的组织表达特异性，确定FtERF5调控的木质素合成相关靶基因，鉴定调控FtERF5的互作蛋白，揭示FtERF5在苦荞体内的功能，全面系统阐述FtERF5调控苦荞抗倒伏的分子机制，为苦荞抗倒伏性状改良和品质育种提供重要的理论基础。

荞麦营养全面，具有良好的药用和保健功效。倒伏严重制约着荞麦的产量和品质，木质素含量与茎秆倒伏密切相关。茉莉酸可以诱导木质素合成相关基因的表达，但是其中的调控机制尚不清楚。本研究发现外源施加茉莉酸可以促进苦荞矮化生长和木质素积累。利用转录组分析，挖掘到受茉莉酸诱导且与木质素合成关键基因高度相关的7个转录因子FtERF5、FtMYB2、FtMYB4、FtMYB11、FtMYB21、FtMYB24、FtMYB50。通过构建候选基因的过量表达毛状根，发现FtMYB2过量表达后显著抑制了毛状根生长，促进了木质素积累，过量表达FtERF5等基因不影响木质素积累。基于多组学联合分析，筛选到与FtMYB2高度相关的转录因子FtWRKY44及2个下游靶基因。阐明了FtMYB2可以通过参与调控木质素积累，进而参与苦荞抗倒伏性的机制。此外，通过进行资源评价与鉴定，筛选出抗倒伏的材料6份，为荞麦育种提供了重要资源。.在本项目的支持下，发表SCI论文3篇，分别发表在Genome Biology 、New Phytologist及Plant Biotechnology Journal杂志；以第三完成人申报国家发明专利1项；培养硕士研究生1名。