Latitude & Light; Phytoplankton Physiomics for a Changing World

纬度

• 批准号: RGPIN-2019-03905
• 负责人: Campbell, Douglas
• 金额: $ 4.01万
• 依托单位: Mount Allison University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=745638
• 关键词: Latitude; Light; Phytoplankton; Physiomics; Changing

Photosynthetic phytoplankton growth supports aquatic productivity, atmospheric gas balances and ultimately fishery harvests. Phytoplankton sinking velocity then determines their interactions with consumers, and their delivery of carbon and nutrients from the surface to the deep ocean. Now these phytoplankton face unprecedented change in their environments. The Campbell group grows diverse phytoplankton cells under multiple environments, while tracking their growth and sinking, to understand their interactions with changing environments. With climate change many phytoplankton are shifting polewards to keep within their preferred temperatures and water qualities, bringing species into new photoperiods. We hypothesize that photoperiod helps determine current phytoplankton distributions, and may limit their future distributions. Low oxygen zones are now spreading in ocean and coastal regions, while human activity imposes new nutrient conditions on coastal waters. We therefore apply matrices of photoperiod, temperatures, nutrients and oxygen to parallel microcultures, while monitoring their growth, sinking rates and physiology, to understand the limits on their current and future distributions. As a byproduct phytoplankton produce toxic Reactive Oxygen Species (ROS). We hypothesize that diffusion limits toxic ROS from leaving large cells, which must rely upon expensive ROS detoxification encoded by their own genes. In contrast small phytoplankton can rely upon ROS diffusion out of the cell for breakdown by co-occurring bacteria. This hypothesis predicts the loss of ROS detoxification genes across diverse small, but not large, phytoplankton, to be tested through genome comparisons. The hypothesis also predicts that small phytoplankton will cope better with internally generated ROS which can leave by diffusion, whereas large phytoplankton will cope better with ROS from outside sources, protected by the same diffusion limitation that renders them sensitive to internally produced ROS. The students in my group learn to apply growth, compositional, and biooptical analyses across the wide taxonomic range of phytoplankton groups, to understand their responses to complex, interacting environmental changes, and where they will grow (or fail to grow) in future. Through their projects students learn transferrable skills designing, analyzing and presenting high throughput, parallel data capture, applicable to many areas.

光合浮游植物的生长支持水生生产力、大气气体平衡和最终的渔业产量。浮游植物的下沉速度决定了它们与消费者的相互作用，以及它们将碳和营养物质从表面输送到深海的过程。现在，这些浮游植物的环境面临着前所未有的变化。坎贝尔小组在多种环境下培养不同的浮游植物细胞，同时跟踪它们的生长和下沉，以了解它们与不断变化的环境的相互作用。随着气候变化，许多浮游植物正在向极地移动，以保持其偏好的温度和水质，从而使物种进入新的光周期。我们假设光周期有助于确定当前浮游植物的分布，并可能限制它们未来的分布。低氧区正在海洋和沿海地区蔓延，而人类活动给沿海水域带来了新的营养条件。因此，我们将光周期、温度、营养物质和氧气的矩阵应用于平行的微培养物，同时监测它们的生长、下沉速率和生理学，以了解它们当前和未来分布的限制。 作为副产品，浮游植物会产生有毒的活性氧（ROS）。我们假设扩散限制了有毒的 ROS 离开大细胞，而大细胞必须依赖于其自身基因编码的昂贵的 ROS 解毒。相比之下，小型浮游植物可以依靠 ROS 扩散到细胞外，并被共生细菌分解。这一假设预测，不同的小型浮游植物（而非大型浮游植物）中 ROS 解毒基因会丢失，并通过基因组比较进行测试。该假设还预测，小型浮游植物将更好地应对内部产生的活性氧，这些活性氧可以通过扩散离开，而大型浮游植物将更好地应对外部来源的活性氧，受到相同的扩散限制的保护，这使得它们对内部产生的活性氧敏感。我小组的学生学习在浮游植物群的广泛分类范围内应用生长、成分和生物光学分析，以了解它们对复杂、相互作用的环境变化的反应，以及它们未来将在哪里生长（或无法生长）。通过他们的项目，学生学习可转移的技能设计、分析和呈现高吞吐量、并行数据捕获，适用于许多领域。