赤霉素信号途径调控拟南芥根尖干细胞命运的分子机制研究

赤霉素通过GID1介导其信号途径降解DELLA蛋白，进而能促进植物生长发育。然而，拟南芥中DELLA蛋白缺失多突变体global表现出根系变短，静止中心细胞和根尖干细胞异常的表型。此外，水稻DELLA蛋白缺失突变体slr1也有类似表型，但其中的调控机制尚不清楚。在拟南芥中，WOX5基因是维持中心细胞和根尖干细胞稳定的关键因子。本项目通过遗传诱变筛选，获得了WOX5的抑制子ROW1（Repressor of WOX5）。ROW1是一个核定位蛋白，并能形成相分离。进一步研究发现ROW1和DELLA蛋白互作，并且DELLA影响ROW1蛋白相分离的形成。本项目拟通过探究GA-DELLA信号途径调控ROW1相分离状态及其功能来揭示赤霉素信号对调控根尖干细胞的新机制，不仅能解开困扰赤霉素研究领域的难题，还可以推动蛋白相分离等国际热点领域的研究，更能进一步为分子育种和农业生产奠定新的理论基础。

Gibberellins promote plant development by mediating the degradation of DELLA protein, a key repressor of growth. However, in Arabidopsis, DELLA protein loss-of-function mutant global showed the phenotypes of shortened roots, abnormal QC cells and root stem cells. Although similar phenotypes were observed in rice slr1 mutants, little is known about the molecular mechanisms that integrate the GA signaling into the QC cells and root stem cells to coordinate cell division and cell expansion. In Arabidopsis, WOX5 gene is the key factor to maintain the stability of QC cells and root stem cells. The ROW1 (repressor of WOX5) was identified by genetic screening. ROW1 protein is localized in nucleus and can form the process of phase separation phenomenon.. Further yeast two hybrid assays showed that ROW1 could interact directly with DELLA protein. And what’s more, DELLA protein could affect the formation of EOW1 phase separation, which may reverse function of ROW1 in regulating WOX5 expression levels. Our project aims to explore how the regulation of ROW1 phase separation mediated by GA signaling in controlling developmental processes in roots, and provide new ideas and insights for revealing new mechanisms of GA signaling pathway in regulating the cell fates of QC cells and root stem cells, which can not only break through the puzzles in GA signaling and protein separation researches, but also further polish the theoretical foundation for molecular breeding and agricultural growth.