EAGER: A Nanobiotechnology Approach to Study the Role of Chloroplasts as Transceivers in Plant ROS Communication

全球大多数农村土地都受到环境压力的影响，包括干旱和极端温度，这些压力强烈抑制植物生长，导致全球作物产量严重损失。推进我们对植物如何响应和耐受胁迫的知识的一个主要限制是理解细胞内和细胞间短命和高反应性植物信号分子的运动和分布。该项目旨在研究植物细胞如何通过关键信号和化学活性氧分子（ROS）来传达环境压力。目前的方法来监测和操纵ROS的生物技术工具的基础上，有限的几个植物模型系统缺乏时间分辨率感测特定的亚细胞区室中的ROS的快速或长期的变化。该研究将利用新兴的纳米生物技术方法来发现由专门的细胞结构（如叶绿体）介导的植物ROS通讯的新机制。合成的和多功能的基于纳米颗粒的工具有可能很容易地从植物模型系统转化为不同的植物物种。该项目将在植物生物学和工程学多个学科的科学家会议上以及在当地的公共科学外联活动中传播成果。来自不同部门和代表性不足的群体的新一代本科生和研究生将在实验室接受关于植物生物学研究和纳米材料工程的培训，并通过纳米生物技术课程在课堂上接受培训。活性氧是植物逆境应答的关键信号分子。植物质外体和叶绿体之间的ROS通讯机制是控制非生物胁迫基因簇表达的关键。已经提出，非生物胁迫诱导ROS质外体波，其被传递到叶绿体，在那里它们触发ROS产生的二次增加。目前还不清楚，如果叶绿体作为收发器接收和发送ROS波产生的质外体。拟议的项目将应用新的ROS监测和操纵纳米粒子，以获得对叶绿体在非生物胁迫期间作为ROS振荡波的接收器，放大器，发生器和调制器的假设作用的机械理解。它将测试和建模的想法，在叶表皮细胞的亚细胞ROS波的振幅，持续时间和相位是唯一与高光，热和臭氧胁迫反应。单壁碳纳米管将被用作体内ROS传感器。这些无限寿命的纳米传感器在近红外区发出荧光，而活组织相对透明。它们不会光漂白，并且具有毫秒时间分辨率和单分子检测的潜力。氧化铈纳米颗粒，可以作为催化活性氧清除剂将被靶向的质外体和叶绿体在这些亚细胞区室的特定的活性氧操纵。该研究将展示独特的纳米生物技术方法的概念证明，以前所未有的时空分辨率研究植物体内信号传递，并有助于我们理解亚细胞ROS信号如何编码源特异性信号调节植物非生物胁迫反应。该奖项反映了NSF的法定使命，并被认为值得通过使用基金会的智力价值和更广泛的影响评估来支持的搜索.

Most global rural land is affected by environmental stresses include drought and extremes in temperature that strongly inhibit plant growth and lead to significant crop yield loss worldwide. A major limitation to advancing our knowledge of how plants respond to and tolerate stress is understanding the movement and distribution of short-lived and highly reactive plant signaling molecules both within and between cells. The project aims to study how plant cells communicate types of environmental stresses through key signaling and chemically reactive molecules of oxygen (ROS). Current approaches to monitor and manipulate ROS are based on biotechnology tools limited to a few plant model systems lacking the temporal resolution to sense rapid or long-term changes in ROS in specific subcellular compartments. The study will utilize emerging nanobiotechnology approaches for discovering novel mechanisms of plant ROS communication mediated by specialized cellular structures such as chloroplasts. Synthetic and versatile nanoparticle-based tools have the potential to be easily translated from plant model systems to diverse plant species. The project will disseminate the results at meetings to scientists across multiple disciplines of plant biology and engineering and at local public science outreach events. A new generation of undergraduate and graduate students from diverse departments and underrepresented groups will be trained in the laboratory on plant biology research and engineering with nanomaterials and in the classroom through a nanobiotechnology course. ROS are key signaling molecules communicating and regulating fine-tuned plant stress responses. The mechanisms involved in plant ROS communication between the plant apoplast and chloroplasts are crucial to control the expression of abiotic stress gene clusters. It has been proposed that abiotic stresses induce ROS apoplastic waves that are transmitted to chloroplasts where they trigger a secondary increase in ROS generation. It is unclear if chloroplasts act as transceivers both receiving and transmitting ROS waves generated in the apoplast. The proposed project will apply novel ROS monitoring and manipulating nanoparticles to gain a mechanistic understanding of the hypothesized role of chloroplasts as receivers, amplifiers, generators, and modulators of ROS oscillatory waves during abiotic stress. It will test and model the idea that the amplitude, duration, and phase of subcellular ROS waves in leaf epidermal cells are uniquely associated with high light, heat, and ozone stress responses. Single walled carbon nanotubes will be used as in vivo ROS sensors. These infinite lifetime nanosensors fluoresce in the near infrared where living tissues are relatively transparent. They do not photobleach and have the potential for millisecond temporal resolution and single molecule detection. Cerium oxide nanoparticles that can act as catalytic ROS scavengers will be targeted to the apoplast and chloroplasts for specific ROS manipulation in these subcellular compartments. The study will demonstrate proof of concept of unique nanobiotechnology approaches to study plant signaling communication in vivo with unprecedented spatiotemporal resolution and contribute to our understanding of how subcellular ROS signals encode source specific signals regulating plant abiotic stress responses.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.