iSAM: Integrative Systems Analysis of the Shoot Apical Meristem

形态发生是生物体在发育过程中由细胞形成的过程。生物体及其组成器官具有明确和可识别的形状和形式，这需要许多细胞的协调作用。然而，尽管广泛关注细胞成分，我们仍然不了解如何产生如此复杂的结构和模式。本项目旨在通过分析、模型构建、生物学测试和改进等过程，了解高等植物茎尖分生组织（SAM）中导致生长和器官产生的形态发生事件。SAM是一群分裂的、未分化的细胞，在植物的整个生命周期中，它们以高度有序的模式在茎尖上产生叶子和其他器官。SAM是一个复杂的自我维持和稳定的结构，在其中心安置了干细胞群，在其外围安置了启动器官。SAM产生构成所有地上植物组织的细胞，并决定侧枝器官的数量、类型和位置。因此，sam是植物结构的基础和主要农艺性状的决定因素。鉴于其重要性，人们对其进行了广泛的研究，并获得了有关其分子和细胞成分的丰富信息。然而，我们不了解这些成分是如何组合成具有特定形状和生长动力学的多细胞结构的。我们希望解决的正是这个问题。我们将基于对活体SAM的生物学观察和关键参数的测量，包括对植物激素的反应，通过建立SAM功能的多层次计算机模型来实现这一目标，这些激素既定义了单个细胞的生长和分裂，也协调了SAM结构的整体行为。该项目的结果将大大增加对重要的SAM系统形态发生的细胞基础的理解。它将产生许多相关的新数据，这些数据将被组织在一个数据库中。这将以生长的虚拟组织的形式支撑SAM生长的第一个完整的空间化细胞模型，其中细胞根据一个基于定量数据确定响应的小网络程序进行机械相互作用和响应。该模型将用于预测性实验，允许解决有关SAM系统的维护，器官发生和形态发生的具体问题。该提案将英国、法国和芬兰的四个领先研究团队联系起来，这些团队之前有过几次相关的联合合作记录，并在成像、建模、植物激素和细胞分裂方面带来协同专业知识和技术，以解决这一重要的系统问题。

Morphogenesis is the process by which organisms are built up from cells during development. Living organisms and their component organs have defined and recognisable shapes and forms, and this requires the coordinated actions of many cells. However, despite extensive focus on the cellular components, we still do not understand how such complex structures and patterns are produced. The goal of this project is to understand the morphogenetic events leading to growth and organ production in the shoot apical meristem (SAM) of higher plants, in an iterative process of analysis, model building, biological testing and refinement. The SAM is a population of dividing, undifferentiated cells that generates the leaves and other organs of plants in highly ordered patterns at shoot tips throughout the life of the plant. The SAM is a complex self-maintaining and stable structure, housing at its centre a population of stem cells and initiating organs on its periphery. The SAM produces the cells that comprise all aboveground plant tissues, and defines the number, type and position of lateral organs. SAMs are thus the basis of plant architecture and determinants of major agronomic traits. In view of its importance, the SAM has been extensively studied and a wealth of information is available concerning its molecular and cellular components. Nevertheless, we do not understand how these components assemble into the multicellular structures that have specific shapes and growth dynamics. It is this question we wish to address. We will do this through building multi-level computer models of SAM function, based on biological observation of living SAMs and measurements of key parameters, including responses to plant hormones that both define the growth and division of individual cells and coordinate the overall behaviour of the SAM structure. The outcome of the project will be a greatly increased understanding of the cellular basis of morphogenesis in the important SAM system. It will generate many relevant new data that will be organised in a database. This will underpin the first complete spatialised cellular model of SAM growth in the form of a growing virtual tissue, in which cells mechanically interact and respond according to a small network programme determining responses based on quantitative data. This model will be used for predictive experimentation allowing specific questions regarding the maintenance, organogenesis and morphogenesis of the SAM system to be addressed. This proposal links four leading research teams in UK, France and Finland, with a previous track record of several relevant joint collaborations, and bringing synergistic expertise and technologies in imaging, modelling, plant hormones and cell division to address this important systems problem.