Collaborative Research: An Integrated Experimental and Computational Approach to Discover Biomechanical Mechanisms of Leaf Epidermal Morphogenesis

叶片的大小和形状是强烈影响作物产量的重要农业性状。单个细胞的生长共同决定了叶片的形态，生物学上的一个主要挑战是了解细胞成分如何排列细胞壁，以影响局部细胞生长的速度和方向。这个项目的重点是发现形成叶表皮的细胞外层的生长控制机制。表皮既是保护叶子的防水层，也是影响叶子大小和形状的不断生长的生物力学外壳。该项目旨在了解细胞信号和细胞骨架模式是如何在贴壁细胞中受到控制的，以及局部生长如何影响组织或整个叶子的特征。更广泛的影响活动包括对团队所有成员(包括本科生和高中生)进行跨学科培训。还将为内布拉斯加州青年科学家方案开发K-12夏令营单元。拟南芥叶表皮形态发生系统非常适合于重大突破。然而，由于缺乏可靠的表型方法来定义遗传途径和分析细胞骨架、细胞壁和细胞几何之间发生的非直观的生物力学相互作用，进展缓慢。这个跨学科的研究团队将创造一种新的实验和计算方法，以发现依赖微管的纤维素微纤维图案如何驱动表皮的极化生长。由此产生的计算模型将预测细胞如何在细胞壁中产生时空异质性，从而驱动这些拼图状细胞的交错生长。重要的是，微管细胞骨架上细胞壁的生物力学反馈控制是植物发育的一个普遍特征。这项拟议的研究将产生数据并创建综合计算模型，揭示细胞壁应力模式如何影响皮质微管和组织形态发生。

The size and shape of leaves are important agricultural traits that strongly influence crop yield. The growth of individual cells collectively determine leaf morphology, and a major challenge in biology is to understand how cellular constituents pattern the cell wall to influence local rates and directions of cell growth. This project focuses on discovering the growth control mechanisms of the outer layer of cells that form the leaf epidermis. The epidermis serves both as a waterproof layer that protects the leaf and as a growing biomechanical shell that influences the size and shape of the leaf. This project aims to understand how cell signaling and cytoskeletal patterning is controlled among adherent cells and how local growth can scale to influence tissue or whole leaf traits. The Broader Impact activities include interdisciplinary training for all members of the team (including undergraduates and high school students). A K-12 summer camp module will also be developed for the Young Nebraska Scientist Program. The Arabidopsis leaf epidermal morphogenesis system is ideally suited for major breakthroughs. However, progress has been slow because of the lack of reliable phenotyping methods to define genetic pathways and analyze the non-intuitive biomechanical interactions that occur among the cytoskeleton, cell wall, and cell geometry. The interdisciplinary research team will create a new experimental and computational approach to discover how microtubule-dependent patterning of cellulose microfibrils drives polarized growth in the epidermis. The resulting computational models will make predictions about the how cells generate the spatial and temporal heterogeneities in the cell wall that drive interdigitated growth of these jig-saw-puzzle shaped cells. Importantly, biomechanical feedback control of the cell wall on the microtubule cytoskeleton is a general feature of plant development. The proposed research will generate data and create integrated computational models that reveal how cell wall stress patterns influence cortical microtubules and tissue morphogenesis.