Organising Tissue Cell Polarity and Growth in Plants

不像我们制造的大多数东西，比如汽车和手机，我们周围的生物结构是通过生长产生的：一棵树从一颗种子生长出来，一个人类的孩子从一个显微镜下的受精卵生长出来。这种增长不是由外部的手引导的，而是自我组织的，由内部规则协调的。复杂的结构可以从这个过程中产生，因为生长和变形以不同的速率发生在组织上，并且优先在特定的方向上。一个主要的挑战是要了解这种通过成长进行自我建设的过程是如何运作的。研究这个问题可能使我们能够以预测的方式调节生长结构，从而使我们能够更有效地利用，管理和与生命系统互动。实现这一目标的一个主要障碍是，我们目前对生长组织中的方向是如何指定和协调的知之甚少。我们最好的工作假设是，这个过程取决于每个细胞都有一个极性，就像一个内部指南针，但这种极性如何在整个组织中传播和协调仍然不清楚。该项目旨在通过研究植物中协调的极性以及它如何导致组织以特定方向生长来解决这个问题。植物细胞被细胞壁包围，阻碍了细胞间的直接通讯。因此，极性协调被认为是间接的，由小分子介导，如植物激素生长素，可以通过细胞壁扩散。我们最近开发了一个一般性的假设，这个过程可能会导致协调的极性在整个组织和这个项目的主要目的是通过实验和计算方法相结合来测试这个和其他hypothesis.To了解极性协调的机制，我们的目标是开关上的基因，已经牵连在极性控制的细胞内生长叶片组织的补丁。通过激活小块组织中的这些基因，我们希望看到周围组织的极性如何受到影响，以及这如何影响细胞的生长，我们可以通过生物成像详细跟踪。这些实验将在正常植物和通过突变去除某些极性成分的植物中进行。我们还打算开发计算建模系统，使我们能够确定特定的假设是否可以解释所观察到的极性和生长变化模式。这将涉及开发新的软件来处理组织的细胞性质以及它们生长和变形的方式。这些实验和计算方法应该使我们能够对极性和生长如何协调达成新的更深入的理解，从而提高我们管理和利用生物系统的能力。

Unlike most things that we manufacture, like cars and phones, the biological structures we see around us are generated through growth: a tree grows from a seed and a human child grows from a microscopic fertilised egg. This growth is not guided by an external hand but is self-organised, coordinated by internal rules. Complex structures can arise from this process because growth and deformation occur at varying rates over tissues and preferentially in particular directions. A major challenge is to understand how this process of self-construction through growth operates. Answering this question may allow us to modulate growing structures in a predictive way and thus enable us to exploit, manage and interact with living systems more effectively. A major block to achieving this goal is that we currently understand little about how orientations are specified and coordinated within growing tissues. Our best working hypothesis is that this process depends on each cell having a polarity, like an internal compass, but how this polarity is propagated and coordinated across a tissue remains unclear. This project aims to address this problem by studying polarity coordinated in plants and how it may lead to tissue growing out in particular orientations. Plant cells are surrounded by walls which impede direct communication from one cell to another. Polarity coordination is therefore thought to operate indirectly, mediated by small molecules, such as the plant hormone auxin, that can diffuse through the cell wall. We have recently developed a general hypothesis for how this process may lead to coordinated polarity across tissues and a major aim of this project is to test this and other hypotheses through a combination of experimental and computational methods.To understand the mechanism of polarity coordination, we aim to switch on genes that have been implicated in polarity control in patches of cells within growing leaf tissue. By activating these genes in small patches of tissue we hope to see how the polarity of the surrounding tissue is affected and how this affects the growth of the cells, which we can follow in detail with bioimaging. These experiments will be conducted in normal plants and also plants in which certain polarity components have been removed through mutation. We also intend to develop computational modelling systems that will allow us to determine whether particular hypotheses can account for the observed patterns of polarity and growth change. This will involve developing new software to deal with both the cellular nature of tissues and the way they grow and deform. Taken together these experimental and computational approaches should enable us to arrive at a new and deeper understanding of how polarity and growth are coordinated and thus advance our ability to manage and exploit biological systems.