Latitude & Light; Phytoplankton Physiomics for a Changing World

光合作用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收成。浮游植物下沉的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层输送到深海。现在这些浮游植物面临着前所未有的环境变化。坎贝尔小组在多种环境下培养各种浮游植物细胞，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两极转移，以保持它们喜欢的温度和水质，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。低氧区目前正在海洋和沿海地区蔓延，而人类活动对沿海水域施加了新的营养条件。因此，我们将光周期、温度、营养和氧气基质应用于平行微培养，同时监测其生长、下沉速率和生理，以了解其当前和未来分布的限制。作为副产物，浮游植物产生有毒的活性氧（ROS）。我们假设扩散限制了有毒ROS离开大细胞，这必须依赖于由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，通过共生细菌进行分解。这一假设预测了各种小型浮游植物中活性氧解毒基因的损失，而不是大型浮游植物，将通过基因组比较进行测试。该假说还预测，小型浮游植物将更好地应对内部产生的ROS，这些ROS可以通过扩散离开，而大型浮游植物将更好地应对来自外部来源的ROS，受到同样的扩散限制的保护，使它们对内部产生的ROS敏感。我小组的学生学习在广泛的浮游植物群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（或不生长）。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。

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.