FIT互作蛋白FPP1/2调控拟南芥铁稳态的分子机制研究

缺铁影响农作物的生长发育和产量。研究植物铁平衡的分子机制有利于耐缺铁农作物的培育。拟南芥中，FIT是铁平衡调控的核心转录因子，调控IRT1和FRO2等铁吸收相关基因。FIT表达于根表皮细胞和中柱细胞，暗示FIT除了在根表皮细胞中参与铁的吸收外，可能在中柱部分具有生物学功能。申请人前期通过在根中柱特异性表达FIT-GFP，采用免疫共沉淀与质谱联用筛选获得2个全新的FIT互作蛋白FPP1/2，但其在根中柱部位是否存新型的铁稳态调控机制尚不清楚。在此基础上，本项目拟采用荧光共振能量转移技术验证FIT与FPP1/2是否于根中柱部位互作；进一步利用遗传学和生理生化方法，鉴定FPP1/2突变所导致的表型变化的生物学机制；最后通过分子生物学和多组学方法，探究FPP1/2调控铁稳态的分子机制。本项目研究结果，为进一步深入研究植物中柱部位铁稳态的分子调控机制提供全新的见解和角度。

Iron deficiency is a worldwide problem in crop production, which affects more than 30% of crops in the world. Therefore, it is critical to determine the regulation mechanism of iron homeostasis, which is vital to solving the problem caused by iron deficiency in crop production. In Arabidopsis, FIT is a critical regulatory hub in iron homeostasis that could directly regulate the iron uptake-related genes including IRT1 and FRO2. Previous studies showed that the FIT was expressed in both the root epidermis and stele cells, indicating that FIT may have potential biological functions in the steles, in addition to participating in iron uptake in the root epidermis. In this project, two novel FIT-interacting proteins FPP1/2 were identified using Co-IP-MS/MS method by specifically expressing FIT-GFP in the root steles in Arabidopsis, which suggested that the FPP1/2 may mediate a new type of iron homeostasis regulation network in the stele cells. Thus, this project plans to use fluorescence resonance energy transfer technology to verify whether FIT and FPP1/2 could interact in the root steles. Genetics, physiological and biochemical methods will be used to identify the biological mechanism of phenotypic changes caused by FPP1/2 mutation. Finally, molecular biology and multi-omics methods will be employed to uncover the molecular mechanism of FPP1/2 in the regulation of iron homeostasis in Arabidopsis. This project will help to further elucidate the regulation mechanism of iron homeostasis in the stele cells in plant roots.