Analysis of regulatory networks underlying morphogenesis of leaf epidermis pavement cells

叶表皮铺装细胞形态发生的调控网络分析

• 批准号: 431219018
• 负责人: Professorin Dr. Katharina Bürstenbinder
• 金额: --
• 依托单位: Arbeitsgruppe Zellbiologie der Pflanzen
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2019
• 资助国家: 德国
• 起止时间: 2018-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/431219018?language=en
• 关键词: Analysis; regulatory; networks; underlying; morphogenesis

The development of multicellular organisms from a fertilized egg cell to complex organisms with specialized tissues and organs requires precise coordination of growth. The basic processes that drive growth are cell division and cell expansion, which generate new cells and increase the size of individual cells, respectively. During cell expansion, cells acquire various distinct shapes to fulfill their specialized functions (cell differentiation). In plants, cell expansion is controlled and restricted by a rigid cell wall that surrounds individual cells outside of the plasma membrane and physically glues neighboring cells. Deposition of cell wall material is mediated by the plant cytoskeleton, comprised of microtubules and actin filaments, which form a highly dynamic intracellular network. The concerted activity of the cell wall and the cytoskeleton is coordinated by complex signaling networks that integrate endogenous and external signals for precise regulation of growth. Leaf epidermis pavement cells form one of the most complex cell shapes in plants with multiple lobes and indentations in their anticlinal walls. In addition to their importance for leaf growth and their protective role for photosynthetically active tissues, pavement cells thus are a popular and suitable model system to study multipolar growth in the context of a tissue of mechanically coupled cells. Genetic and pharmaceutical studies, mostly in the model plant Arabidopsis thaliana, have identified several factors that control pavement cell morphogenesis. The precise mechanisms and principles underlying shape formation, however, remain largely enigmatic. In our previous work we identified a member of a plant-specific class of microtubule-associated proteins, IQ67 DOMAIN5 (IQD5), as novel regulator of pavement cell shape and cell wall composition, which likely integrates calcium signaling at the microtubule cytoskeleton. In addition, we have developed a software-tool, which for the first time enables fully automatic detection and comparative quantitative analysis of pavement cell shape from microscopy images. Our first analyses of pavement cell shape in naturally occurring Arabidopsis ecotypes revealed large intraspecific variation that provide a suitable basis to identify associated genetic loci. Within the proposed project we aim to functionally characterize the role of IQD5 in regulation of microtubule organization and in cellular signaling pathways, using cell biology and reverse-genetics approaches. In addition, we will use forward-genetics approaches to identify novel regulators by linking genotypic and phenotypic variation within Arabidopsis accessions and by screening of mutant collections. Collectively, the combined analysis of pavement cell shape regulation by reverse- and forward-genetics approaches will provide a suitable framework to investigate mechanisms of cell morphogenesis and will contribute to a more holistic understanding of the underlying principles.

多细胞生物从受精卵细胞到具有专门组织和器官的复杂生物的发展需要精确的生长协调。驱动生长的基本过程是细胞分裂和细胞扩增，它们分别产生新细胞和增加单个细胞的大小。在细胞扩增过程中，细胞获得各种不同的形状以实现其特定功能（细胞分化）。在植物中，细胞扩张受到刚性细胞壁的控制和限制，刚性细胞壁包围质膜外的单个细胞，并物理粘合相邻细胞。细胞壁物质的沉积是由植物细胞骨架介导的，细胞骨架由微管和肌动蛋白丝组成，它们形成高度动态的细胞内网络。细胞壁和细胞骨架的协同活动由复杂的信号网络协调，该信号网络整合内源和外部信号以精确调节生长。叶表皮铺装细胞是植物中形态最复杂的细胞之一，垂周壁上有多个裂片和凹陷。除了它们对叶片生长的重要性和它们对光合活性组织的保护作用之外，铺面细胞因此是研究机械耦合细胞组织背景下多极生长的流行和合适的模型系统。遗传和药物研究，主要是在模式植物拟南芥，已经确定了几个因素，控制路面细胞形态发生。然而，形状形成背后的精确机制和原则在很大程度上仍然是个谜。在我们以前的工作中，我们确定了一种植物特异性微管相关蛋白IQ67 DOMAIN 5（IQD5）的成员，作为路面细胞形状和细胞壁组成的新型调节剂，它可能在微管细胞骨架上整合钙信号。此外，我们还开发了一种软件工具，首次实现了从显微镜图像中对路面细胞形状进行全自动检测和比较定量分析。我们的第一个分析路面细胞的形状在自然发生的拟南芥生态型揭示了大的种内变异，提供了一个合适的基础，以确定相关的遗传位点。在拟议的项目中，我们的目标是使用细胞生物学和反向遗传学方法，从功能上表征IQD5在微管组织调节和细胞信号传导途径中的作用。此外，我们将使用正向遗传学的方法，以确定新的监管机构，通过连接基因型和表型的变化，在拟南芥的加入和筛选突变体的集合。总的来说，路面细胞形状调控的反向和正向遗传学方法的综合分析将提供一个合适的框架，以调查细胞形态发生的机制，并将有助于更全面地了解基本原则。