侧生分生组织（Axillary Meristem，AM）形成于叶原基根部的一团分生组织细胞，其发生直接影响植物株型的建立，决定作物的产量，是发育生物学的重要问题，并可指导作物改良。由于AM发生区的细胞数量非常少，基因表达水平较低，并涉及复杂的干细胞重建过程，传统手段的研究难于进行。转录调控在侧芽发生过程中发挥重要作用，对其中转录调控网络的解析是揭示AM形成分子机制的关键。我们的前期工作利用系统生物学技术在全基因组水平重构了AM发生过程的上游基因调控网络，并发现和鉴定了新的调控因子。研究同时发现LAS，CUC3是关键性的调控中心，但其作用机制也就是调控的下游基因尚不明确。本项目拟将细胞类型特异的转录谱分析用于特异诱导体系，并结合ChIP-seq技术，鉴定CUC3基因的下游转录谱。该项目的实施将鉴定出上述基因的下游基因，拓展AM发生的调控网络，阐释AM发生的分子机制。

Axillary meristems (AMs), which initiate from a mass of stem cells in the axils of leaf primodia, play important roles in plant architecture, and are crucial for crop productivity. Studies on AM initiation are not only the fundamental issue in plant development biology, but also can guide for crop design. Due to limited cells in the boundary region where AM initiate, the gene expression levels are low. The reestablishment of stem cells are also involved in this process that traditional methods cannot make a breakthrough. Transcriptional regulation play important roles in this process. To dissect the gene regulation network is key to illustrate the mechanism for AM initiation. Our previous work employed systems biology to study the gene regulatory network underlying AM initiation. We identified some novel factors involved and reconstructed the upstream regulatory network. We also found that although LAS, CUC3 genes play crucial roles, their mechanisms that is their downstream regulatory genes are still largely unknown. This project will analyze cell-type specific transcriptomes in a specific inducible system, and combine chromatin immunoprecipitation together with seq technique (ChIP-seq), to dissect the downstream transcriptomes of these genes. This will identify the target genes of CUC3, and expand the regulatory network, which will further illustrate the molecular mechanisms involved in AM initiation.