核孔蛋白NUP62调控开花时间的分子机制

开花是植物生长发育阶段最重要的组成部分，直接影响植物生长的世代长短和繁殖速度。改良植物开花时间性状不仅对扩大新品种适宜种植范围极其重要，对于提高植物产量，增强植物抗逆性也具有重要意义。核孔复合体是核质信息交换的通道，有多个核孔蛋白被报道突变后开花提前，但具体机制不清楚。FLC是开花时间调控的抑制因子，对它的转录调控研究的比较清楚，但是在蛋白水平的调控很少有报道。本项目将研究核孔蛋白NUP62调控开花时间的功能并阐明分子机制；研究NUP62转运FLC入核的过程和机制；研究NUP62互作蛋白ALDH通过与NUP62的互作调控FLC的入核来调控开花时间的机制；研究核孔蛋白NUP62亚复合体其他成员在调控开花时间和转运FLC入核中的作用及机理。我们的研究将解析一条新的调控FLC的开花时间途径，也将解析核孔蛋白通过调控FLC的入核来调控开花时间的机理，为核孔复合体调控蛋白的核质穿梭提供理论依据。

The transition from vegetative to reproductive development is the most important process during the life cycle of a flowering plant, which directly affects the generation length and reproductive speed of plant growth. Improving the flowering time traits of plants is not only very important for expanding the suitable planting range of new varieties, but also for improving the yield of plants (especially crops) and enhancing the stress resistance of plants. The nuclear pore complex (NPC) is a macromolecular assembly of protein subcomplexes that serves as a key regulator of macromolecule (RNAs and proteins) trafficking between the cytoplasm and nucleoplasm. Some nucleoporins have been reported to function in flowering time regulation, but their mechanisms remain unknown. FLC is a key repressor that controls the flowering time properly. The role of FLC has been extensively studied at the transcriptional level, however, the FLC role at post-translational level, such as FLC modification, stability and transport, is only at the beginning. In this proposed project, we will conduct in-depth investigations on how nucleoporin NUP62 regulates flowering time and will elucidate the molecular mechanisms. We will explore the process of NUP62 mediating FLC nuclear import and illustrate the mechanism; we will also explore how the NUP62-interacting protein ALDH works together with NUP62 to mediate FLC nuclear import and regulates flowering time. We will also identify whether the other nucleoporins that form NUP62 subcomplex function in the flowering time regulation through modulation of FLC nuclear import. Our findings will reveal a new mechanism on regulation of FLC in floral transition and uncover a role of nucleoporin in modulation of FLC nuclear import. Our findings will also provide knowledge to understand the biological functions of NPCs in nucleocytoplasmic shuttling.