Metabolomics of stomatal immunity in the disease triangle

作物不断暴露于微生物病原体中，引起植物病害，导致严重的产量损失。病原体进入植物的一个主要途径是通过叶片表面上的一对保护细胞形成的微孔。这些孔被称为气孔，植物通过气孔释放氧气和水蒸气，并从大气中吸收二氧化碳。二氧化碳用于合成碳水化合物和其他生物材料/代谢物。本研究的目的是了解在其他环境条件下，如干旱和大气中二氧化碳含量上升，保护细胞中的代谢物如何在病原体触发的气孔运动中发挥调节作用。这些研究将提高对气孔孔径与环境条件和疾病之间联系机制的认识。由于保护细胞动态控制气孔的大小，从而控制病原体的进入、CO2的吸收和植物的水分流失，其功能影响植物的生长和产量。更好地了解植物的气孔运动有助于合理的作物育种和工程设计，以提高抗病性和产量。由于代谢调节在生物学中无处不在，因此这项研究将产生广泛的影响。该项目将能够对学生（包括妇女和代表性不足的群体）进行跨学科培训。由于植物代谢物与我们的日常生活密切相关，“植物代谢物”的外展活动将延伸到普通大众。让学生和公众接触现代科学研究将有助于培养高素质的未来科学家和公民，他们将为建设一个繁荣的社会和一个可持续发展的世界做出贡献。研究小组将应用分子遗传学和组学方法来评估代谢物在病原体反应过程中调节保护细胞和叶肉过程以及气孔运动中的功能。核心假设是，在不同环境条件下，特别是干旱和二氧化碳升高的情况下，保护细胞代谢物的变化在病原体触发的气孔运动中起着重要的调节作用。这些假设将通过三个目标进行评估：A)使用LC-MS和GC-MS方法量化病原体触发的气孔关闭和重新打开过程中代谢物的变化。B)利用反向遗传学和药理学方法验证病原体相关保护细胞代谢物在气孔孔径调节中的作用，并表征不同环境条件下的相互作用。C)阐明病原体诱导的气孔关闭和重新打开的保护细胞网络。实验将确定在细菌疾病和不同环境因素的背景下气孔运动所必需的代谢物。该项目将揭示病原体诱导的气孔运动的新调节机制，并将有助于代谢物调节作为细胞调节重要信号和代谢过程的通用机制的新兴概念。将产生的知识可以为合理的作物育种/工程提供信息，以改善气孔防御，而不会破坏影响作物产量的其他途径。该奖项由植物生物相互作用项目和细胞动力学与功能集群共同资助，分别隶属于综合生物系统和分子与细胞生物科学部门。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Crops are continually exposed to microbial pathogens, which cause plant disease, leading to severe yield loss. A major route of pathogen entry into plants is through microscopic pores formed by pairs of guard cells on leaf surfaces. The pores are called stomata, through which plants release oxygen and water vapor and take up carbon dioxide (CO2) from the atmosphere. The CO2 is used for synthesizing carbohydrates and other biomaterials/metabolites. The goal of this research is to understand how metabolites in guard cells play regulatory roles in pathogen-triggered stomatal movements in the context of other environmental conditions, such as drought and rising CO2 in the atmosphere. The investigations will improve understanding of the mechanisms that link stomatal aperture to environmental conditions and diseases. Because guard cells dynamically control the size of the stomatal pore and thus control pathogen entry, CO2 uptake and plant water loss, their function impacts plant growth and yield. A better understanding of plant stomatal movements should foster rational crop breeding and engineering for enhanced disease resistance and yield. Since metabolite regulation is ubiquitous in biology the research will have broad impact. The project will enable cross-disciplinary training of students (including women and underrepresented groups). Since plant metabolites are tightly related to our daily lives, the “Plant Metabolites” outreach activities will extend to the general public. Exposing students and the public to modern scientific research will contribute to preparing highly qualified future scientists and citizens, who will contribute to building a prosperous society and a sustainable world. The research team will apply molecular genetics and omics approaches to assess the functions of metabolites in regulating guard cell and mesophyll processes and stomatal movements during pathogen response. The central hypothesis is that changes in guard cell metabolites play important regulatory roles in pathogen-triggered stomatal movements in the context of different environmental conditions, particularly drought and rising CO2. The hypotheses will be evaluated with three objectives: A) Quantify metabolite changes during pathogen-triggered stomatal closing and re-opening using LC-MS and GC-MS approaches. B) Verify roles of pathogen-related guard cell metabolites in stomatal aperture regulation and characterize interactions in different environmental conditions using reverse genetics and pharmacology. C) Elucidate guard cell networks of pathogen-induced stomatal closure and re-opening. The experiments will identify metabolites essential for stomatal movement in the context of bacterial disease and different environmental factors. The project will reveal novel regulatory mechanisms underlying pathogen-induced stomatal movements and will contribute to the emerging concept of metabolite regulation as a versatile mechanism by which cells regulate important signaling and metabolic processes. The knowledge that will be generated can inform rational crop breeding/engineering to improve stomatal defense without disruption of other pathways that impact crop yield. This award is co-funded by the Plant Biotic Interactions program and the Cellular Dynamics and Function cluster in the divisions of Integrative Organismal Systems and Molecular and Cellular Biosciences, respectively.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.