胚珠是种子的前体，其发育正常与否直接关系到植物个体的繁衍及产量。植物个体产生的胚珠数量有限，胚珠发育因而成为产量形成的关键因素。此外，胚珠具有复杂的组织极性，包含孢子体及配子体两个世代的细胞。因此，研究胚珠发育的分子调控机制，对于了解种子的形成和发育至关重要，而且有助于回答细胞间信号交流机制等基础生物学问题。已有研究揭示了控制胚珠发育的部分转录因子。然而，调控这些转录因子发挥功能的元件尚未被发现。申请人目前鉴定了拟南芥核转运蛋白IMF，其突变体胚珠发育异常，表现在珠被细胞极性生长缺陷、胚囊不能正常形成，造成雌性部分不育。本项目拟对imf进行深入的表型分析，明确其在胚珠发育中的作用；通过蛋白互作及候选基因筛选等方法，发掘鉴定依赖于IMF进行核转运的转录因子；结合转录组测序，对该转录因子及下游途径进行深入解析，从而阐明IMF介导转录因子入核、调控胚珠发育的信号途径，为深入解析胚珠发育的分子机制

Ovules are progenitors of seeds. Ovular development is therefore critical for plant reproduction and seed yield. Because the limited number of ovules an individual plant produces is much fewer than that of pollen grains, ovule development is thus a limiting factor for crop yield. In addition to its agronomical impact, ovules are multi-cellular tissues not only with a complex tissue polarity but also contain cells from two generations: the sporophytic inner and outer integument cells as well as the gametophytic embryo sac. Therefore, to investigate the molecular mechanism underlying ovular development is not only critical for agricultural productivity but also useful to understand basic biological questions, such as mechanisms of tissue polarity establishment and inter-cellular communication. .Studies in the past decade uncovered many transcription factors (TFs) controlling ovule development. However, regulatory components of these TFs are obscure. ..Previously, we characterized an Arabidopsis gene, IMPORTIN-FOR-FERTILIZATION (IMF). Functional loss of IMF resulted in defective ovule development. Specifically, imf mutants could not form regular outer integuments, contain defective embryo sacs and are partially female sterile. .This project thus aims at understanding the signaling pathway and related components in IMF-mediated ovule development. Specifically, we propose to 1) characterize the ovular developmental defects of imf in details; 2) identify key transcription factors whose nucleo-cytoplasmic shuttling depends on IMF by using protein interaction assays; 3) identify interacting proteins of these TFs and dissect downstream events mediated by IMF-TFs. By these approaches, we hope to establish the IMF-TF signaling pathway controlling ovule development and provide novel insights into molecular mechanism underlying ovule development.