Mechanisms of Plant Cell Morphogenesis: ARP2/3 Function and Trichome Distortion in Arabidopsis

拟议活动的智力价值Szymanski博士的研究计划的长期目标是利用拟南芥形态突变体和所有可用的实验工具来了解细胞形状控制的基本机制。本研究的主要目的是确定植物中是否存在一种称为ARP2/3复合物的肌动蛋白丝成核机器，如果存在，其在极化生长过程中的功能。本研究的中心假设是拟南芥ARP2/3复合物在表皮发育过程中调节肌动蛋白丝成核和液泡生物发生。他的团队计划通过以下三个具体目标来检验我们的中心假设。具体目的1：确定扭曲的毛状体表型是否完全由ARP2/3亚基基因突变引起。具体目标#2：测试拟南芥ARP2/3复合物的存在及其基本功能。Szymanski使用正向分子遗传学，新型活细胞成像分析和生化工具是研究ARP2/3在多细胞生物中的功能的创新方法。在完成拟议的工作后，他的小组希望确定工厂ARP2/3复合体是否必不可少。他希望建立ARP2/3亚基定位、肌动蛋白细胞骨架的组织和细胞中特定的细胞器运输步骤之间的功能关系。这些数据将为复杂生物体如何利用ARP2/3亚基控制细胞形状和组织功能提供新的知识。希曼斯基博士完全有资格承担这项拟议的研究。他拥有最广泛的ARP2/3亚基突变集，并生成了广泛的DNA和基于蛋白质的试剂，可以进行功能分析。Szymanski实验室的研究和学习活动的整合确保了他的项目对社会产生广泛的影响。Szymanski博士发表了两篇关于植物形态发生的书籍章节和两篇以教学为导向的评论。这项拨款要求继续资助本科生、研究生和博士后研究员的研究机会。研究生和研究生的部分研究经历将包括实验室和课堂教学机会。一些本科生支持将用于教授工程和计算机科学专业的学生图像处理和突变表型定量。Szymanski博士积极参与MARC-AIM和部门研究生招募计划，这两个计划都侧重于增加少数民族学生对科学的参与。希曼斯基博士将把本提案中开发的材料提供给科学界，其中一些将用于大学和高中的遗传学实验室练习。最后，希曼斯基博士，作为一名公司私家侦探。在仪器拨款方面，他已经为普渡大学的许多生物学家改善了荧光显微镜的基础设施和使用。总的来说，本提案中所描述的努力旨在将基础研究活动转化为广泛的教育经验，从而促进科学过程的兴奋和相关性。

Intellectual Merit of the Proposed ActivitiesThe long-term goal of Dr. Szymanski's research program is to use Arabidopsis morphology mutants and all available experimental tools to understand the basic mechanisms of cell shape control. The primary objective of this proposal is to determine if an actin filament-nucleating machine, termed the ARP2/3 complex, exists in plants, and if so, its function during polarized growth. The central hypothesis of this proposal is that an Arabidopsis ARP2/3 complex modulates actin filament nucleation and vacuole biogenesis during epidermal development. His group plans to test our central hypothesis by pursuing the following three specific aims.Specific Aim #1: To determine if the distorted trichome phenotype is caused exclusively by mutation of ARP2/3 subunit genes.Specific Aim #2: To test for the existence and essential function of a seven protein Arabidopsis ARP2/3 complex.Dr. Szymanski's use of forward molecular genetics, novel live cell imaging assays, and biochemical tools is an innovative approach to study ARP2/3 function in a multicellular organism. Upon completion of the proposed work his group expects to determine if a plant ARP2/3 complex is essential. He expects to establish functional relationships between ARP2/3 subunit localization, the organization of the actin cytoskeleton, and specific organelle trafficking steps in the cell. These data will provide new knowledge about how complex organisms utilize ARP2/3 subunits to control cell shape and tissue function. Dr. Szymanski is extremely well qualified to undertake the proposed research. He has the most extensive set of ARP2/3 subunit mutants, and has generated an extensive collection of DNA and protein-based reagents that will permit functional analyses. Broader impacts of the proposed research The integration of research and learning activities in the Szymanski laboratory ensures that his program has a broad impact on society. Dr. Szymanski published two book chapters and two teaching-oriented reviews on plant morphogenesis. This grant requests continued funding for undergraduate, graduate, and post-doctoral fellow research opportunities. Part of the research experience for graduate and post-graduate students will include lab and classroom teaching opportunities. Some of the undergraduate student support will be used to teach engineering and computer science students image processing and mutant phenotype quantitation. Dr. Szymanski actively participates in the MARC-AIM and a departmental graduate student recruiting program, both of which focus on increasing minority student participation in science. Dr. Szymanski will make the materials developed in this proposal available to the scientific community, and some of them will be used in college and high school genetics laboratory exercises. Last, Dr. Szymanski, as a Co.P.I. on instrumentation grants, has improved the infrastructure and use of fluorescence microscopy for many biologists at Purdue University. Collectively, the efforts described in this proposal are aimed at translating basic research activities into broad-based educational experiences that promote the excitement and relevance of the scientific process.