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塑造其进化和形态方面发挥着重要作用，但植物生物学家对植物中发生触觉感知的分子机制仍然知之甚少。尽管植物机械传感器的身份尚不清楚，但似乎很明显，这种传感器的机械刺激会触发细胞质 Ca2+ 快速且短暂的增加。 人们认为 Ca2+ 的这种变化会引发各种反应，从仅限于受刺激细胞的防御反应，到延伸到整个器官（例如根或芽）的生长变化，甚至影响整个植物的生长习性的变化。 然而，将这些与触摸相关的 Ca2+ 变化与后续反应联系起来的精确事件仍有待确定。 Gilroy 实验室的初步数据表明，这些 Ca2+ 变化会引起 pH 值和活性氧等信号分子水平的快速局部变化，进而在调节随后对机械刺激的发育反应中发挥作用。因此，该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响应中的作用。为了实现这一目标，吉尔罗伊实验室将：(1) 定义细胞内机械诱导的 Ca2+ 变化的空间和时间“指纹”(2) 定义 Ca2+ 依赖性 ROS 产生在机械感知/响应中的作用(3) 定义 Ca2+、pH 和生长之间的关系。这些目标将通过生成表达被设计为 Ca2+ 和 pH 传感器的蛋白质的植物来实现 可使用光学显微镜检测。然后，这些传感器将用于可视化触摸相关 Ca2+ 信号所表现出的空间和时间“指纹”。然后，通过使用这些 Ca2+ 响应成分的两种突变体破坏植物中可能的 Ca2+ 响应元件，并评估用破坏这些 Ca2+ 依赖元件活性的药物处理的植物中的触摸响应，来评估这些 Ca2+ 变化的作用。特别是，Gilroy 实验室对这些反应的初步表征表明，Ca2+ 依赖性 ROS 产生是这些反应的关键组成部分。因此，我们将在突变植物中探究 Ca2+ 作用的机制，其中负责 ROS 产生的蛋白质已被破坏。 因此，该研究计划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了解之外，了解这种触摸传感的运作方式也具有重要的实际意义。作物的耐旱性通常与根系穿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有助于指导育种和工程策略，以产生更抗旱的农业。该项目还将研究和教育的紧密结合。博士后研究人员、研究生和本科生将接受现代分子和细胞生物学技术的培训。 PI 和 CoPI 致力于增加女性和代表性不足的少数群体在各个科学层面的代表性。这一重点将通过威斯康星大学麦迪逊分校提供的广泛的多元化项目来促进，例如威斯康星州少数族裔参与联盟、中西部科学、技术、工程和数学联盟、DELTA 项目以及 NSF 资助的教学研究与学习整合中心内的多元化研究所。 PI 实验室也正在进行翻新，配备定制的实验室空间，旨在供残疾学生充分使用，以促进通过这些项目招募的残疾学生充分融入实验室内的研究。