Environmental stress and signaling based on reactive oxygen species among planktonic protists

基于浮游原生生物活性氧的环境应激和信号传导

• 批准号: 1434842
• 负责人: Suzanne Strom
• 金额: $ 59.96万
• 依托单位: Western Washington University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-09-01 至 2020-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1434842&HistoricalAwards=false
• 关键词: Environmental; stress; signaling; based; reactive

Traditionally marine food webs have been studied on the basis of size, assuming that larger organisms eat smaller ones, and that they eat everything in a given size range. This simplification has not stood the test of time, especially for the smallest microbial plankton. Not only do smaller organisms sometimes eat larger ones, there is growing evidence that chemical signaling and defenses are acting at these small scales. This project addresses the central premise that the oxidative stress response is an emergent property of phototrophic cellular systems, with implications for nearly every aspect of a phytoplankton cell's life in the upper ocean. Oxidative stress (OS), arising from numerous environmental stressors, can damage cells and lead to release of compounds suspected to be potent signals regulating protist behavior. Through chemical signaling, OS is hypothesized to govern relationships among environmental variability, phytoplankton condition, and protist predation. The study of these integrated processes has three overarching objectives: 1) Use light stress to create oxidatively stressed phytoplankton in the laboratory, and characterize the response using an array of fluorescent probes, biochemical measurements, and physiological assays. In addition, production and release of potential signal molecules will be quantified. 2) Examine protist predation and behavioral responses to oxidatively stressed phytoplankton and associated chemical signals. Responses will be investigated by means of manipulation experiments and resulting signal chemistry. 3) Investigate the prevalence of OS, its environmental correlates, and the microzooplankton predation response in a local embayment. Broader impacts will build directly on these experimental and observational activities. The project will support several graduate students and involve undergraduates through two programs at Shannon Point Marine Center, including one targeting under-represented minorities. Funds will support a significant collection of heterotrophic protists isolates. The fluorometer will be used in developing new units for at least 3 different Western Washington University marine-related courses. In addition, graduate students will use protist images as the basis for outreach activities aimed at the general public and K-12 students.This research will help to elucidate some of the many ways in which the OS response can affect phytoplankton fitness, characterizing the position of key coastal species along an OS response spectrum. Findings will also inform the relatively new and exciting field of chemical signaling in planktonic communities. Finally, this study will help elucidate the links between environmental stress, phytoplankton response, and predation in planktonic ecosystems. These links relate to central issues in biological oceanography, including the predator-prey interactions that influence bloom demise, and the mechanisms by which protists feed selectively and thereby structure prey communities. The research is a cross-cutting endeavor that unites subjects usually studied in isolation through a novel conceptual framework. Outcomes have the potential to generate broadly applicable insights into the ecological and evolutionary regulation of this key trophic link in planktonic food webs.

传统上，基于大小的海洋食品网，假设较大的生物体吃了较小的生物，并且它们在给定尺寸范围内吃了所有东西。 这种简化尚未经受时间的考验，特别是对于最小的微生物浮游生物。 较小的生物不仅有时会吃较大的生物，而且越来越多的证据表明化学信号传导和防御能力在这些小尺度上起作用。 该项目解决了氧化应激反应是光营养细胞系统的新兴特性的中心前提，对浮游植物细胞在上海上的生命的几乎每个方面都有影响。由许多环境压力源引起的氧化应激（OS）会损害细胞并导致释放的化合物，该化合物被认为是调节原生物行为的有效信号。通过化学信号传导，假设OS可以控制环境变异性，浮游植物条件和捕食者的关系。对这些综合过程的研究具有三个总体目标：1）使用光应力在实验室中创建氧化应激的浮游植物，并使用一系列荧光探针，生化测量和生理测定法对响应进行表征。此外，将量化潜在信号分子的产生和释放。 2）检查对氧化应激的浮游植物和相关化学信号的原生物捕食和行为反应。响应将通过操纵实验和由此产生的信号化学进行研究。 3）研究OS的患病率，其环境相关性和局部嵌入中的微Zooplankton捕食反应。更广泛的影响将直接基于这些实验和观察活动。该项目将支持几名研究生，并通过在香农角海洋中心的两个计划中参与本科生，其中包括一个目标不足的少数民族。资金将支持大量的异养生物分离株。荧光计将用于开发至少3个不同西部华盛顿大学海洋有关的新单元。此外，研究生将使用原生图像作为针对公众和K-12学生的外展活动的基础。这项研究将有助于阐明OS响应可能影响植物浮游生物健身的众多方式中的某些方式，从而表征了OS响应范围沿途关键沿海物种的位置。调查结果还将为浮游社区中相对较新的化学信号传导领域提供信息。最后，这项研究将有助于阐明环境压力，浮游植物反应和浮游生态系统中的捕食之间的联系。这些联系与生物海洋学中的核心问题有关，包括影响绽放灭亡的捕食者 - 捕集互动，以及生物学家选择性地喂养猎物群落的机制。这项研究是一项跨记录的努力，通常通过新颖的概念框架孤立地研究受试者。结果有可能在浮游食品网中对这一主要营养环节的生态和进化调节产生广泛适用的见解。