CAREER: Linking Lateral Cell Polarity with Tissue Patterning in Plant Development

细胞分裂和特化是多细胞生物生长发育的重要过程。与动物系统相比，对植物如何调节细胞分裂和细胞极性特化的机制了解有限。细胞极性被定义为在发育或生理的任何方面沿单轴不对称，不对称的蛋白质定位是极化细胞的常见属性。以前，一组受体激酶被确定在各种细胞类型中显示极性定位，并在发育中发挥作用。这些蛋白质为研究植物细胞极性提供了一套全新的概念和分子工具。这个教师早期职业发展（Career）项目的目标是研究细胞极性和发育之间的联系，并整合积极的研究模块，旨在提高生物学本科生的参与度和保留率。这些模块将在实验课程中进行，学生将参与真实的研究并生成将直接集成到研究项目中的材料。这门高度互动的课程将建立一个包括同行、研究生和教师在内的科学社区。在培养当今学生的科学热情和专业知识方面，建立社区意识和对更大事业的贡献是必不可少的要素。除了这些参与转运的蛋白质外，很少有植物蛋白具有极性定位的特征。极性定位激酶（POLARLY localization kinase, PLKs）是一组跨膜受体激酶，定位于各种根细胞类型的外侧（内/外）质膜结构域，并在器官模式中发挥作用。假设PLKs通过其定向信号功能直接影响根发育中的细胞分裂和分化。为了确定横向细胞极性和组织模式之间的机制联系，本CAREER项目旨在：1)表征PLK的发育作用，2)阐明PLK极性定位的细胞力学，以及3)解剖PLK的功能和定位域以确定极性基序。该项目旨在从不同于定向运输的角度研究植物细胞极性是如何建立和维持的，这支持了长期以来的假设，即定向信号和位置信息是植物发育的关键驱动因素。该项目短期内更广泛的影响将是基础信息的获取和传播以及STEM学生的招聘和培训。学生将接受遗传和分子方法以及尖端显微镜技术的培训；项目的策划和执行；并且，有效的科学交流来确立自己作为学者和导师的地位。从长远来看，获得的知识可以作为有选择地利用现有或产生改良根系性状的基础，以最大限度地发挥根系功能并支持植物生产力。此外，这项研究可能揭示了动物系统中细胞极性机制的相似之处，为确定多细胞真核生物极性和发育的共同逻辑提供了一个框架。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Cell division and specialization are essential processes in the growth and development of multicellular organisms. In comparison to animal systems, there is limited mechanistic insight into how plants modulate cell division and specialization with respect to cell polarity. Cell polarity is defined as asymmetry in any aspect of development or physiology along a single axis and asymmetric protein localization is a frequent attribute of polarized cells. Previously a set of receptor kinases was identified that display polar localization in various cell types and have roles in development. These proteins provide a novel set of conceptual and molecular tools to investigate cell polarity in plants. The goals of this Faculty Early Career Development (CAREER) project is to study the links between cell polarity and development and to integrate active research modules designed to improve engagement and retention of undergraduate students in biology. These modules will be conducted in a laboratory course in which students will engage in authentic research and generate materials that will be directly integrated into the research project. This highly interactive course will establish a scientific community that includes peers, graduate students, and faculty. Building a sense of community and contribution to something larger are essential elements in the cultivation of scientific passion and expertise in today's students.Beyond those proteins involved in transport, very few plant proteins with polar localization have been characterized. A group of transmembrane receptor kinases, POLARLY LOCALIZED KINASEs (PLKs), are localized to the lateral (inner/outer) plasma membrane domains of various root cell types and have roles in organ patterning. It is hypothesized that PLKs directly influence cell division and differentiation in root development through their function in directional signaling. To identify mechanistic links between lateral cell polarity and tissue patterning this CAREER project aims to: 1) characterize the developmental roles of PLKs, 2) elucidate the cellular mechanics of PLK polar localization, and 3) dissect PLK functional and localization domains to identify polarity motifs. This project is poised to address how plant cell polarity is established and maintained from a perspective distinct from directional transport, and which, supports the long standing hypothesis that directional signaling and positional information are key drivers of plant development. The short-term broader impacts of this project will be the acquisition and dissemination of basic information and the recruitment and training of STEM students. Students will receive training in genetic and molecular approaches and cutting-edge microscopy techniques; planning and execution of projects; and, effective scientific communication to establish themselves as scholars and mentors. In the long term, the acquired knowledge can serve as a foundation to selectively exploit existing or generate improved root traits that maximize root function and support plant productivity. In addition, this study may reveal parallels to cell polarity mechanisms in animal systems, providing a framework to identify a common logic to polarity and development across multicellular eukaryotes.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.