Probing Molecular Interactions in the Nitrogen Fixing Cyanobacteria-Feather Moss Symbiosis

2002年，有报道称，能够收集光作为能量和生物质的微生物，以及从大气中产生氮的微生物，在高纬度或北方森林中形成大量生态系统的羽毛苔藓上定居。随后，人们发现这些微生物提供了维持北方森林的大量氮，而羽毛苔藓分泌的化学物质吸引了这些微生物。这些微生物（蓝藻）和苔藓进入一种共生关系，蓝藻为苔藓提供氮，苔藓为蓝藻提供碳。这项工作将更详细地研究苔藓和蓝藻如何通过确定基本元素和交换化合物来建立这种生态上重要的伙伴关系。了解附生共生的复杂性增加了驯化作物-植物-蓝藻共生的潜力。研究生和本科生都将作为研究活动的一部分接受培训。此外，将与艺术中心设计学院建立独特的合作关系，为高级艺术学生开发一个资助的工作室设计课程，这是一个关注共生的主题。该设计课程的一名学生也将被选中参加J. Craig Venter Institute的DesignMatters奖学金。通过吸引和整合科学和设计学生，将开发新的教育和信息交流形式。在北方森林中，固氮蓝藻与羽毛苔藓形成共生关系，并为这些系统提供最大的固定氮输入。虽然羽毛苔藓与蓝藻的关联在生态水平上已经得到了很好的研究，但在分子水平上的研究却很少。这项工作在三个独特的水平上提供了这种关联的额外特征：细胞分化、分子定位和基因相互作用关系。有三个主要目的：建立和表现型的基因敲除蓝藻的集合。检查苔藓和蓝藻之间的元素分子交换。建立定量测定共生过程中不同蓝藻细胞类型的异囊频率和候选共生相关基因转录的方法。这些方法之间的协同作用将发现新的分子相互作用，建立物质交换，并为更好地表征共生过程中的细胞分化提供分子工具。考虑到蓝藻-羽毛苔藓结合的广泛自然成功，了解合作伙伴之间发生的分子交换对于模拟这种高纬度资源在变暖世界中的影响至关重要。这项研究将为共生机制的进化提供一个窗口，以确定它们是否可以在作物物种中进行改造。研究生和本科生都将作为研究活动的一部分接受培训。此外，将与艺术中心设计学院建立独特的合作关系，为高级艺术学生开发一个资助的工作室设计课程，这是一个关注共生的主题。该设计课程的一名学生也将被选中参加J. Craig Venter Institute的DesignMatters奖学金。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。

In 2002, it was reported that microbes capable of harvesting light for energy and biomass, as well as generating nitrogen from the atmosphere, colonize feather mosses that form a huge amount of the ecosystem in high latitude, or boreal, forests. Subsequently, it has been found that these microbes provide a large amount of the nitrogen that sustains boreal forests and that the feather mosses secrete chemicals that attract the microbes. These microbes (cyanobacteria) and mosses enter a symbiosis, with the cyanobacteria providing nitrogen to the moss and the moss providing carbon to the cyanobacteria. The work will examine in finer detail how the moss and cyanobacteria establish this ecologically important partnership by determining essential elements and exchanged compounds. Understanding the intricacies of epiphytic symbioses increases the potential for a domesticated crop-plant-cyanobacteria symbioses. Both graduate and undergraduate students will be trained as part of the research activities. Additionally, a unique collaboration will be formed with the ArtCenter College of Design to develop a funded studio design course aimed at senior level art students, such a subject matter focused on symbiosis. A student from this design course will also be selected for a DesignMatters Fellowship onsite at the J. Craig Venter Institute. By engaging and integrating science and design students, novel forms of education and information exchange will be developed. In boreal forests, nitrogen-fixing cyanobacteria form symbiotic associations with feather mosses and provide the largest input of fixed-N into these systems. While the feather moss-cyanobacteria association has been well-studied at the ecological level, it is sparingly studied at the molecular level. The work provides additional characterization of the association at three unique levels: cellular differentiation, molecular localization, and gene to interaction relationships. There are three main aims: Build and phenotype a collection of gene-knockout cyanobacteria. Examine the elemental molecular exchange between moss and cyanobacteria. Develop methods to quantitatively determine heterocyst frequency and transcription of candidate symbiosis-related genes by different cyanobacterial cell types during symbiosis. The synergy between these approaches will discover new molecular interactions, establish material exchange, and provide molecular tools for better characterization of cellular differentiation during symbiosis. Given the widespread natural success of the cyanobacteria-feather moss association, it will be critical to understand the molecular exchanges taking place between the partners to model the impact of this high latitude resource in a warming world. The research will provide a window on the evolution of symbiosis mechanisms to determine whether they could be engineered in a crop species. Both graduate and undergraduate students will be trained as part of the research activities. Additionally, a unique collaboration will be formed with the ArtCenter College of Design to develop a funded studio design course aimed at senior level art students, such a subject matter focused on symbiosis. A student from this design course will also be selected for a DesignMatters Fellowship onsite at the J. Craig Venter Institute.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.