Collaborative Research: Systemic Signaling Networks in Arabidopsis

诸如食草动物或病原体攻击等压力会严重限制植物的生长和发育，例如，通过减少作物产量和影响世界各地的粮食安全。植物拥有天然的感觉系统，使它们能够检测到这些压力，然后对它们进行防御。因此，确定这些反应系统是如何运作的，对于了解植物如何在自然界中生存和茁壮成长，以及如何有效地利用这些先天反应来提高农业的复原力都是重要的。最近的研究在表征植物体内这些信号系统方面取得了关键进展，揭示了植物部署了一种内部生化通信系统，该系统将胁迫信息从其感知位置传播到植物身体的其他部位。这些信息随后触发防御措施的产生，例如有毒化学物质的积累，甚至为植物未受攻击的部分做好防御准备。这种通信系统运行迅速，在几分钟内将信息传播到整个工厂。尽管在协调每一种植物的快速逆境反应方面发挥了如此重要的作用，但触发这一系统并随后在整个植物中传递逆境信号的细胞组件仍然缺乏明确的定义。本项目将重点研究两种主要的细胞信使--钙离子和活性氧物种--在传播这些快速应激信号中的作用。调查还将探索植物释放的氨基酸如何作为这种反应的初始触发因素。这项工作将培训研究生和博士后研究员，帮助他们为未来的研究和科学生涯做好准备。该项目还将提供有关植物逆境反应的公共教育，并为学生提供有效的科学交流培训。最近的研究揭示了植物中通过依赖钙和活性氧物种的事件介导的快速系统信号系统。这项研究计划试图将我们对这些过程的理解扩展到支持这一信令网络的通道和组织结构的水平。拟南芥谷氨酸样受体(GLR)通道和产生活性氧的NADPH氧化酶与这种基于钙离子的信号的快速系统传播有关。因此，本研究将重点研究这些蛋白在局部创伤系统传递、病原激发子(Flg22)和盐胁迫中的作用(S)。其具体目的是：(1)比较在响应这些刺激的远程信号的启动和传播过程中发生的Ca~(2+)和ROS信号的模式，并确定支持这些活动的通道和ROS相关酶的空间和时间特征；以及(2)探索谷氨酸和其他氨基酸信号如何参与触发这些远程信号。这些目标将使用生物报告成像和突变和分子分析相结合的方法来实现。这项研究将揭示植物快速系统信号转导的分子机制。该项目将帮助确定钙和活性氧物种的空间和时间变化，这些物种传递整个植物的压力信息。这项研究还将有助于确定关于每种压力的信息是否可能编码在特定的信号动态中。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Stresses such as herbivore or pathogen attack can severely limit plant growth and development, for example, by reducing crop production and impacting food security around the World. Plants possess natural sensory systems that allow them to detect these stresses and then mount defenses against them. Defining how these response systems operate is therefore important in both understanding how plants survive and thrive in the natural world and how to effectively capitalize on these innate responses to improve the resilience of agriculture. Recent research has made key advances in characterizing these signaling systems within the plant, revealing that plants deploy an internal biochemical communication system that broadcasts stress information from its site of perception to the rest of the plant body. This information then triggers the production of defenses such as the accumulation of toxic chemicals, priming even the non-attacked parts of the plant for defense. This communication system operates quickly, spreading information throughout the plant over the course of minutes. Despite such a central role in coordinating each plant’s rapid stress responses, the cellular components that trigger this system and then transmit the stress signal throughout the plant remain poorly defined. This project will focus on characterizing the role of two major cellular messengers, the calcium ion and reactive oxygen species, in propagating these rapid stress signals. The investigation will also explore how amino acids released by the plant may act as initial triggers for this response. This work will train graduate students and postdoctoral fellows to help prepare them for their future careers in research and science. The project will also provide public education on plant stress responses and provide training to students in effective science communication.Recent studies have revealed a rapid systemic signaling system in plants mediated through Ca2+- and reactive oxygen species-dependent events. This research program seeks to extend our understanding of these processes to the levels of the channels and tissue architectures that support this signaling network. The Arabidopsis thaliana Glutamate-Like Receptor (GLR) channels and reactive oxygen species-producing NADPH oxidases have been linked to this rapid systemic propagation of Ca2+-based signals. Therefore, this study will focus on defining the role(s) of these proteins in systemic transmission of local wound, pathogen elicitor (flg22) and salt stresses. The specific aims are to: (1) compare the patterns of Ca2+ and ROS signaling that occur during the initiation and propagation of long-distance signals in response to these stimuli and define the spatial and temporal characteristics of the channels and ROS-related enzymes supporting these activities; and (2) explore how glutamate and other amino acid signals are involved in triggering these long-distance signals. These goals will be accomplished using a combination of bioreporter imaging and mutant and molecular analyses. This study will reveal new insight into the molecular machinery underlying rapid plant systemic signaling. The project will help define the spatial and temporal changes in calcium and reactive oxygen species that relay information about stresses throughout the plant. The research will also help define whether information about each stress is likely encoded in specific signaling dynamics.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.