The meristematic regulatory network controlling the floral transition (BLOOM-NET)

控制花转变的分生组织调控网络（BLOOM-NET）

• 批准号: 93529320
• 负责人: Professor Dr. George Coupland, Ph.D.
• 金额: --
• 依托单位: Centre for Plant Sciences
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2009
• 资助国家: 德国
• 起止时间: 2008-12-31 至 2012-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/93529320?language=en
• 关键词: meristematic; regulatory; network; controlling; floral

The overall aim of this project is to define the complex regulatory network that acts in the shoot apical meristem (SAM) to regulate the timing of transition to flowering, and to model quantitative and dynamic changes in this network during the floral transition.Several proteins with major functions in this process have been elucidated by genetic analyses in recent years. Nevertheless, the precise interplay and temporal behaviour, as well as the characteristics of the components that underpin the robustness of this regulatory system, have not been defined yet. This information is essential to predict the effects of mutations or environmental changes on flowering time. Ultimately, it will allow the adjustment of flowering time in crops of economic importance, and ensures that this transition occurs when required. We will focus on a sub-set of MADS box transcription factors (TFs) that have been shown to be the key regulators of the floral transition in the model species Arabidopsis thaliana. The exact timing of flowering is regulated by a tight balance between these transcriptional activators and suppressors. Our aim is to perform iterative cycles of wetlab experiments and modelling, to obtain comprehensive and quantitative data sets that lead to novel and testable hypotheses. Quantitative information derived from the wet experiments will be integrated in a simple wiring diagram describing all known qualitative interactions between the major regulatory components of the flowering system. Towards the end of the project this will lead to a mathematical model describing the regulatory steps controlling flowering time in the meristem. The following specific objectives are postulated:- Determine the concentrations of key-regulators (MADS proteins) in the shoot apical meristem (SAM) over time and link this to phenotypic output (i.e. the flowering time) under standard and perturbed conditions.- Obtain comprehensive binding site data-sets (i.e. target genes) of the various MADS-factors using a novel ChIP-SEQ approach.- Obtain the temporal transcriptome from the meristem of wild-type (WT) and mutant plants at various time points before and directly after the transition to reproductive development, and compare these data with the direct targets of TFs.- Determine the dimerization affinities of the MADS box TF molecules. Predict target sites at the genome level and model target site binding affinity and MADSfactor dimerization affinities.- Integrate the quantitative and qualitative aspects of the components of the network in a mathematical model that predicts the time of flowering as a function of balances between suppressors and activators.

本项目的总体目标是确定植物茎尖分生组织（SAM）中调控开花转变时间的复杂调控网络，并模拟花转变过程中该网络的定量和动态变化，近年来通过遗传分析阐明了在这一过程中起主要作用的几种蛋白质。然而，确切的相互作用和时间行为，以及支撑这一监管体系稳健性的组成部分的特征，尚未得到界定。这些信息对于预测突变或环境变化对开花时间的影响至关重要。最终，它将允许调整具有经济重要性的作物的开花时间，并确保这种过渡在需要时发生。我们将专注于一个子集的MADS盒转录因子（TF）已被证明是模式物种拟南芥的花转变的关键调节因子。开花的确切时间由这些转录激活子和抑制子之间的紧密平衡来调节。我们的目标是进行湿实验室实验和建模的迭代循环，以获得全面和定量的数据集，从而得出新颖和可检验的假设。来自湿实验的定量信息将被集成在一个简单的接线图描述所有已知的开花系统的主要调控组件之间的定性相互作用。接近项目结束时，这将导致一个数学模型，描述控制开花时间的分生组织的监管步骤。设想的具体目标如下： 确定随着时间的推移茎尖分生组织（SAM）中关键调节因子（MADS蛋白）的浓度，并将其与标准和扰动条件下的表型输出（即开花时间）联系起来。 使用新的ChIP-SEQ方法获得各种MADS因子的综合结合位点数据集（即靶基因）。 在过渡到生殖发育之前和之后的不同时间点，从野生型（WT）和突变体植物的分生组织获得时间转录组，并将这些数据与TF的直接靶标进行比较。 测定MADS盒TF分子的二聚化亲和力。在基因组水平预测靶位点，并对靶位点结合亲和力和MADS因子二聚化亲和力进行建模。 将网络组件的定量和定性方面整合到一个数学模型中，该模型预测开花时间作为抑制因子和激活因子之间平衡的函数。