Collaborative Research: Constitutive and Inducible Predation Defenses in Cyanobacteria

陆生植物具有多样而复杂的防御捕食和病原体的机制，但水生生态系统中光合微生物的防御机制却鲜为人知。聚球藻是水生/海洋蓝藻，对全球初级生产力有很大贡献。本计画将采用两种主要方法来研究聚球藻对原生生物捕食者的防御。实验将检查细胞表面蛋白质提供组成性（连续表达）防御的机制，并测定聚球藻菌株之间和针对不同捕食者类型的这种防御的一般性。其次，共培养技术，其中聚球藻生长在捕食者的存在下，将被用来表征蛋白质为基础的诱导防御，可能会出现在响应捕食。聚集体的形成作为一种可能的诱导防御聚球藻也将在现场和实验室环境中进行检查。团聚体的形成是重要的生态地球化学和生态功能的水生生物群落，因为团聚体可以是独特的生态地球化学过程的网站。该研究在多个层面上是交叉的：它在受控实验室和自然环境中检查了组成性和诱导性防御;它利用了可用的聚球藻基因组套件，以实现微生物防御过程的机械调查;它代表了生态学和基因组学方法的综合，以研究微生物相互作用，这是生物地球化学循环和生物多样性维持的基础。水生生态系统该项目的更广泛影响包括支持研究生和本科生，包括香农角海洋中心海洋科学本科生方案多文化倡议的少数民族参与者。其他影响包括为小学和高中学生开发教学模块，以及维护和分发文化收藏品。

Terrestrial plants have diverse and sophisticated mechanisms for defending against predation and pathogens, but the defenses of photosynthetic microbes in aquatic ecosystems are much less well understood. Synechococcus are aquatic/marine cyanobacteria that substantially contribute to global primary productivity. This project will employ two main approaches to study Synechococcus defenses against protist predators. Experiments will examine the mechanism(s) by which cell surface proteins provide a constitutive (continuously expressed) defense and assay the generality of this defense among Synechococcus strains and against diverse predator types. Secondly, co-culture techniques, in which Synechococcus are grown in the presence of predators, will be used to characterize protein-based induced defenses that may arise in response to predation. The formation of aggregates as a possible induced defense by Synechococcus will also be examined in field and laboratory settings. Aggregate formation is important for the biogeochemistry and ecological functioning of planktonic communities since aggregates can be the site of unique biogeochemical processes. The research is cross-cutting on a number of levels: it examines constitutive and induced defenses in both controlled laboratory and natural settings; it leverages the suite of available Synechococcus genomes to enable a mechanistic investigation of microbial defense processes; and it represents a synthesis of ecological and genomic approaches to the study of microbial interactions that are fundamental to biogeochemical cycling and the maintenance of biodiversity in aquatic ecosystems. Broader impacts of this project include support of graduate and undergraduate students, including ethnic minority participants in Shannon Point Marine Center's Multicultural Initiatives in Marine Science Undergraduate Program (MIMSUP). Other impacts include development of instructional modules for elementary and high school students, and maintenance and distribution of culture collections.