表皮毛广泛存在于陆生植物的地上部组织，是植物与环境之间的一道屏障，参与植物对逆境响应等重要生物学过程。同时，表皮毛也是研究植物细胞命运调控的优良模式系统。揭示表皮毛细胞形成和发育的关键因子和调控机制，具有重要的理论和应用价值。拟南芥HD-Zip家族转录因子GLABRA 2（GL2）是调控表皮毛形成和发育的关键因子，其功能丧失导致表皮毛严重缺失，发育受阻。本项目将以GL2为线索，一方面通过地塞米松诱导的GL2瞬时表达系统、基因芯片、染色质免疫共沉淀-芯片等实验，系统的建立GL2下游调控路径网络；另一方面通过筛选gl2-3遗传逆转突变体，克隆和鉴定与GL2遗传互作的新因子，并阐明他们与GL2及其他控制表皮毛发育的基因之间的互作机制，完善GL2介导的表皮毛发育遗传调控网络。通过本项目的研究，将进一步完善植物表皮毛形成和发育的分子调控模型，为通过改造表皮毛来提高植物的抗逆性奠定理论基础。

Trichomes, which differentiate from epidermal cells, cover most of the aerial parts of terrestrial plants. Trichome serves as a barrier between plants and the environment, play a very important role in protecting plants from environment stress. Trichome is considered as an elegant model system for studying cell fate specification. Therefore, revealing the key factors, as well as their molecular regulation mechanisms involved in controlling trichome cell initiation and development, have very important values both in theoretical and application levels. The transcription factor GLABRA 2(GL2) is a member of HD-Zip gene family. It acts as a master regulator during the trichome initiation and the following developmental processes, and the loss of GL2 functions results in a severe trichome depletion phenotype. However, the downstream pathways of Gl2 in regulation of trichome development remains unknown. In this project, we will further explore the functions of GL2 in two ways. On one hand, we will determine the direct target genes and downstream pathways of GL2, using dexamethasone (DEX) induced GL2 transient expression system, microarray, Chromatin Immunoprecipitation-chip (ChIP-chip), DEX/ cycloheximide (CHX) treatment, and ChIP experiments. On the other hand, we will carry out a genetic modifier screening of the gl2-3 mutant, clone and identify new factors which genetically interact with GL2 during trichome development. This research is not only useful in understanding the molecular mechanism of Gl2 in regulation of trichome development, it also has potential applications in enhancing plant abiotic stress tolerance.