气孔是植物表皮上重要的特化细胞结构，调控着植物光合作用和蒸腾作用所需气体交换和水分蒸发。拟南芥FOUR LIPS（FLP）是第一个被鉴定的调控气孔发育后期细胞分裂和分化的关键MYB转录因子。我们在前期flp-1突变体EMS诱变突变体筛选中发现，flp-1 xs01c突变体表现出比flp-1明显加剧的异常气孔表型,导致表皮细胞冗余分裂、细胞分化受阻。图位克隆结果发现XS01C编码一个F-box蛋白，但是否作为SCF复合体的组成部分并通过泛素降解途径参与气孔发育还没有报道。本项目中拟利用分子生物学、生物化学和细胞生物学等技术，探讨XS01C与相应气孔发育后期的关键调控因子的网络关系，验证蛋白泛素化也是气孔发育重要调控途径之一，研究结果为深入理解植物发育中细胞分裂和分化调控机制提供新依据。

Stomata are plant-specific epidermal structures which play important function in gas exchanges requiring for the process of photosynthesis and water evaporation. Arabidopsis FOUR LIPS (FLP) is the first identified key MYB transcription factor regulating the terminal cell division and differentiation during stomatal development. By means of screening of EMS-mutated flp-1 mutants, we found that flp-1 xs01c mutant displays an aggressive stomatal defective phenotype in comparing with flp-1 single mutant, leading to excessive cell divisions and retarded cell differentiation. Map-based cloning analysis indicates that XS01C encodes an F-box protein, a putative component of SCF complexes, however whether the ubiquitination regulatory pathway plays a role during stomatal development has not been reported. Using approaches of molecular, biochemical and cellular biology, we will probe the regulatory network between XS01C and other key factors that function at the terminal stages of stomatal development, identify the involvement of protein ubiquitination pathway during stomatal development. The results will provide new evidences in revealing the mechanism of controlling of cell division and differentiation during plant development.