Role of the bZIP transcription factor PERIANTHIA in the regulatory network underlying meristem function and floral patterning

本研究旨在从机制水平上阐明PERIANTHIA （PAN）这一bZIP转录因子在分生组织功能和花型形成的调控网络中的作用。PAN在茎尖分生组织和幼花原基中都很活跃，这是正确确定花被器官数量的必要条件。我们发现除了这一作用，PAN还通过激活AGAMOUS （AG）在花发育中发挥重要作用，AGAMOUS是花型形成和干细胞控制所必需的核心调节因子。此外，pan突变还会影响茎尖分生组织中干细胞系统核心成员的表达。我们现在提议研究PAN如何能够控制这两个非常不同的功能，即芽分生组织中的细胞增殖和新兴花中的细胞分化。具体目的是：(1)通过表达谱和全基因组结合研究鉴定PAN靶点。(2) PAN辅助因子的识别与分析。(3) PAN网络新基因的发现。(4)将PAN整合到分生组织控制和花型形成的已知调控网络中。(5)对PAN调控机制的认识。该项目将极大地促进我们对分生组织功能和花模式的调控网络的理解，并阐明PAN如何作为分生组织细胞增殖和分化之间的分子开关。在基础设施层面，社区不仅将受益于产生的大规模数据集，更重要的是，我们将在项目期间实现染色质免疫沉淀微阵列检测技术的进步。这些技术将立即提供给其他AFGN/NSF2010小组，甚至在发表之前。

This proposal is aimed at elucidating the role of PERIANTHIA (PAN), a bZIP transcription factor, in the regulatory network that underlies meristem function and floral patterning on a mechanistic level. PAN is active both in the shoot apical meristem as well as in young floral primordia, where it is necessary for the correct specification of perianth organ number. We have found that in addition to this role, PAN has important functions in floral development by activating AGAMOUS (AG), a core regulator necessary for patterning as well as stem cell control. Furthermore, pan mutations affect the expression of central players of the stem cell system in the shoot apical meristem. We are now proposing to study how PAN is able to control these two very diverse functions, namely cell proliferation in the shoot meristem and cell differentiation in emerging flowers. The specific aims are: (1) Identification of PAN targets by expression profiling and genome-wide binding studies. (2) Identification and analysis of PAN co-factors. (3) Discovery of novel genes in the PAN network. (4) Integration of PAN into known regulatory networks of meristem control and floral patterning. (5) Mechanistic understanding of PAN regulation. The proposed project will substantially advance our understanding of the regulatory network underlying meristem function and floral patterning and elucidate how can PAN act as a molecular switch between proliferation and differentiation of meristematic cells. On the infrastructure level, the community will not only benefit from the large-scale datasets produced, but more importantly from the advancements in chromatin-immunoprecipitation with microarray detection technologies we will achieve during the project. These technologies will be made available to other AFGN/NSF2010 groups immediately, even prior to publication.