Cellular Mechanisms of Mechanotransduction in Arabidopsis

拟南芥机械力转导的细胞机制

• 批准号: 0641288
• 负责人: Simon Gilroy
• 金额: $ 49.97万
• 依托单位: University of Wisconsin-Madison
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-07-15 至 2011-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0641288&HistoricalAwards=false
• 关键词: Cellular; Mechanisms; Mechanotransduction; Arabidopsis

Scientific goals: Despite the fundamental role of plant responses to mechanical forces in shaping their evolution and form, plant biologists still have a remarkably incomplete idea of the molecular mechanism whereby touch perception occurs in plants. Although the identity of the plant mechanical sensor is unknown, it seems clear that mechanical stimulation of such a sensor triggers rapid and transient increases in cytoplasmic Ca2+. This change in Ca2+ is then thought to trigger reactions ranging from defense responses limited to the stimulated cell, to alterations in growth that extend across entire organs, such as the root or shoot, and even changes in growth habit that affect the whole plant. However, the precise events linking these touch-related Ca2+ changes to subsequent responses also remain to be determined. Preliminary data from the Gilroy Lab suggests that these Ca2+ changes elicit rapid and localized alterations in the levels of signaling molecules such as pH and reactive oxygen species that in turn play roles in regulating the subsequent developmental response to mechanical stimulation. This research program therefore seeks to provide a clearer cell and molecular framework defining the roles of Ca2+ signals in the mechanical sensing response of plants. To achieve this aim, the Gilroy lab will:(1) Define the spatial and temporal ''fingerprints'' of mechanically-induced Ca2+ changes within the cell(2) Define the role of Ca2+-dependent ROS production in mechanical perception/response(3) Define the relationship between Ca2+, pH and growth.These goals will be accomplished through the generation of plants expressing proteins engineered to act as Ca2+ and pH sensors detectable using light microscopy. These sensors will then be used to visualize the ''fingerprints'' in space and time exhibited by the touch-related Ca2+ signals. The role of these Ca2+ changes will then be assessed by disrupting likely Ca2+-responsive elements in the plant through use of both mutants of these Ca2+ responsive components and assessing touch responses in plants treated with drugs that disrupt the activity of these Ca2+-dependent elements. In particular, initial characterization of these responses in the Gilroy Lab implies that Ca2+-dependent ROS production is a key component of these responses. Therefore, the mechanism of Ca2+ action will be probed in mutant plants in which the proteins responsible for ROS production have been disrupted. This research program will therefore help to define the cell and molecular signaling elements responsible for triggering and coordinating plant mechanical perception and response. Broader impact: In addition to providing a fundamental insight into the mechanosensory systems of the plant, understanding how this touch sensing operates has important practical implications. Drought tolerance in crops is often linked to how efficiently and deeply the root system can penetrate the soil. Thus, understanding how roots sense and respond to soil obstacles and impedance has the potential to help direct breeding and engineering strategies to generate more drought resistant agriculture.This project will also feature a strong integration of research and education. Postdoctoral researchers, graduate students and undergraduates will be trained in modern molecular and cell biological techniques. The PI and CoPI are committed to increasing the representation of women and underrepresented minorities at all levels of science. This emphasis will be facilitated through the extensive diversity-oriented programs available at UW Madison such as the Wisconsin Alliance for Minority Participation, the Midwest Alliance in Science, Technology, Engineering and Mathematics, the DELTA program and the Diversity Institute within the NSF sponsored Center for the Integration of Teaching Research and Learning. The PIs laboratory is also being renovated with customized laboratory space designed to be fully useable by disabled students to facilitate full inclusion of the students with disabilities recruited through these programs into research within the laboratory.

科学目标：尽管植物对机械力的反应在其进化和形态中起着基本作用，但植物生物学家对植物触觉感知发生的分子机制仍然有一个非常不完整的想法。虽然植物机械传感器的身份尚不清楚，但似乎很清楚的是，这种传感器的机械刺激会触发细胞质Ca2+的快速和短暂增加。这种Ca2+的变化被认为会引发一系列反应，从仅限于受刺激细胞的防御反应，到扩展到整个器官（如根或芽）的生长变化，甚至影响整个植物的生长习惯的变化。然而，将这些与触摸相关的Ca2+变化与随后的反应联系起来的确切事件也仍有待确定。Gilroy实验室的初步数据表明，这些Ca2+变化引起信号分子（如pH值和活性氧）水平的快速和局部改变，进而在调节随后对机械刺激的发育反应中发挥作用。因此，本研究项目旨在提供一个更清晰的细胞和分子框架，定义Ca2+信号在植物机械传感反应中的作用。为了实现这一目标，Gilroy实验室将：(1)定义细胞内机械诱导的Ca2+变化的时空“指纹”(2)定义Ca2+依赖性ROS生产在机械感知/反应中的作用(3)定义Ca2+， pH和生长之间的关系。这些目标将通过产生表达蛋白质的植物来实现，这些蛋白质被设计成使用光学显微镜检测到的Ca2+和pH传感器。然后，这些传感器将用于可视化与触摸相关的Ca2+信号在空间和时间上展示的“指纹”。这些Ca2+变化的作用将通过破坏植物中可能的Ca2+响应元件来评估，通过使用这些Ca2+响应元件的两种突变体和评估用药物处理的植物的触摸反应来破坏这些Ca2+依赖元件的活性。特别是，Gilroy实验室对这些反应的初步表征表明，Ca2+依赖性ROS的产生是这些反应的关键组成部分。因此，Ca2+作用的机制将在突变植物中被探测，其中负责ROS产生的蛋白质已经被破坏。因此，该研究项目将有助于定义负责触发和协调植物机械感知和反应的细胞和分子信号元件。更广泛的影响：除了提供对植物机械感觉系统的基本见解外，了解这种触摸感应如何运作具有重要的实际意义。作物的耐旱性通常与根系渗透土壤的效率和深度有关。因此，了解根系如何感知和响应土壤障碍和阻抗有可能帮助指导育种和工程策略，以产生更抗旱的农业。该项目还将以研究和教育的紧密结合为特色。博士后、研究生和本科生将接受现代分子和细胞生物学技术方面的培训。PI和CoPI致力于增加妇女和代表性不足的少数民族在各级科学领域的代表性。这种强调将通过威斯康星大学麦迪逊分校广泛的以多样性为导向的项目来促进，比如威斯康星少数民族参与联盟、中西部科学、技术、工程和数学联盟、DELTA项目和美国国家科学基金会赞助的教学研究与学习整合中心内的多样性研究所。PIs的实验室也正在进行翻新，为残疾学生提供定制的实验室空间，以促进通过这些项目招募的残疾学生充分参与实验室的研究。