V-Morph_Unravelling how the mechanical regulation of local variability shapes reproducible plant organs

V-Morph_揭示局部变异的机械调节如何塑造可再生的植物器官

• 批准号: 355722357
• 负责人: Professor Dr. Arezki Boudaoud
• 金额: --
• 依托单位: Laboratoire RDP UMR 5667
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2018
• 资助国家: 德国
• 起止时间: 2017-12-31 至 2021-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/355722357?language=en
• 关键词: Morph_Unravelling; how; mechanical; regulation; local

Significant loss in agricultural products is caused by increasingly variable climate and vulnerability of crops to pathogen attacks or extreme environmental conditions. In addition, the agro-industry and the final market often require highly homogeneous crops. This raises the issue of resilience: How to produce robust and homogeneous crops? Here we address the corresponding key question in developmental biology: How do organs form with consistent sizes and shapes in the face of internal and external perturbations? We have assembled an interdisciplinary team to resolve the apparent dichotomy between highly variable cells and robust organs.Previous research has focused on mutants and conditions that affect the global size and shape of organs, enabling the discovery of a large number of regulators. However, most analyses have considered only average cell behaviours, overlooking local heterogeneity and stochastic variation. Here we adopt an orthogonal approach: We screen for mutants with enhanced variability in organ size or shape. Plants produce many flowers, allowing us to detect variability within an individual organism. We have chosen the abaxial sepal, the outermost leaf-like floral organ, for its accessibility for imaging and micromanipulation: the whole process of organogenesis from a primordium to the mature organ can be observed with a confocal microscope. Variability of sepal size and shape can be assessed within an individual plant.Based on our previous work, we propose that tissue mechanics and mechanosensing are key regulators of organ variability, because morphogenesis directly depends on the mechanical control of growth and because mechanical stress is largely prescribed by organ size and shape. We will test this hypothesis in Arabidopsis thaliana, chosen for the availability of genetic and molecular resources. Our main objectives are (i) to analyse spatial and temporal variability in sepal morphogenesis at all scales, considering growth and its effectors, (ii) to identify and characterise genes that regulate variability, by performing a directed screen among mutants affecting the cell wall, plant hydraulics, and mechanosensing, and (iii) to integrate the corresponding mechanisms in mechanical models of growth and test these models experimentally, notably by local mechanical and genetic perturbations to sepals.Overall, our project addresses a central question in developmental biology and is relevant to food security, especially in the context of increasing climatic fluctuations. On the one hand, we will isolate and characterise molecular regulators of the robustness of flower organs. We will overexpress these regulators in plant lines and examine if these lines have more homogeneous organs (e.g. homogenous siliques). On the other hand, we will develop biophysical measurements in the context of plant sciences, which may apply to a broad range of R&D problems, from fruit firmness to biomaterial properties or biomechanical resilience.

农产品的重大损失是由于气候日益多变，作物易受病原体攻击或极端环境条件的影响。此外，农产工业和最终市场往往需要高度同质的作物。这就提出了适应性的问题：如何生产健壮和同质的作物？在这里，我们解决了发育生物学中相应的关键问题：面对内部和外部的扰动，器官如何形成一致的大小和形状？我们组建了一个跨学科的团队，以解决高度可变的细胞和强大的器官之间的明显二分法。以前的研究集中在影响器官的整体大小和形状的突变体和条件，使大量的监管机构的发现。然而，大多数分析只考虑了平均细胞行为，忽略了局部异质性和随机变化。在这里，我们采用了正交的方法：我们筛选突变体与增强变异的器官大小或形状。植物产生许多花，使我们能够检测个体生物体内的变异性。我们已经选择了远轴萼片，最外面的叶状花器官，其可访问性的成像和显微操作：从原基到成熟器官的器官发生的整个过程可以用共聚焦显微镜观察。萼片大小和形状的变异性可以在单个plant.Based上，我们以前的工作，我们提出，组织力学和mechanosensing的器官变异性的关键调节器，因为形态直接依赖于生长的机械控制，因为机械应力在很大程度上是由器官的大小和形状。我们将在拟南芥中测试这一假设，选择遗传和分子资源的可用性。我们的主要目标是（i）分析空间和时间变异性萼片形态发生在所有尺度上，考虑到生长及其效应，（ii）确定和筛选基因，调节变异性，通过进行定向筛选突变体影响细胞壁，植物水力学，和mechanosensing，和（iii）整合相应的机制，在力学模型的增长和测试这些模型的实验，总的来说，我们的项目解决了发育生物学中的一个核心问题，与粮食安全有关，特别是在气候波动增加的情况下。一方面，我们将分离和鉴定花器官健壮性的分子调控因子。我们将在植物品系中过表达这些调节剂，并检查这些品系是否具有更同质的器官（例如同质的长角果）。另一方面，我们将在植物科学的背景下开发生物物理测量，这可能适用于广泛的R&D问题，从水果硬度到生物材料特性或生物力学弹性。