Ocean Acidification: The Influence of Ocean Acidification and Rising Temperature on Phytoplankton Proteome Composition

近年来，一些研究表明，海洋酸化对海洋浮游植物的生理产生重大影响。虽然最著名的研究集中在钙化生物上，但也有关于非钙化浮游植物的研究，如海洋蓝藻和硅藻。三个特别值得注意的意见包括：1）海洋固氮蓝细菌的生长和固氮速率随着酸化而增加，2）两个最丰富的海洋蓝细菌群体，原绿球藻和聚球藻之间的反应差异，其中后者的生长对酸化有积极的反应，而前者没有，和3）由于降低pH值时铁的可利用性降低以及络合化学中的最终转变，海洋硅藻和颗石藻中铁胁迫水平增加。这些都表明，海洋酸化有可能造成大的变化：浮游植物群落的组成，这一社会的敏感性，铁的供应，和海洋氮地球化学循环。在这个项目中，伍兹霍尔海洋研究所的一个研究小组将通过量化四种海洋浮游植物蛋白质组的变化来研究与海洋酸化相关的环境刺激所启动的生理机制：丰富的蓝藻聚球藻和原绿球藻，关键的固氮蓝藻Crocosphaera和南极硅藻Nitzschia sp.，应对海洋酸化。近年来，该团队利用液相色谱质谱系统调整和开发了海洋微生物的定量蛋白质组学能力。这一方法实际上已成为常规做法，可应用于与海洋酸化有关的各种问题。此外，由于海洋酸化和全球变暖之间的气候联系，还将研究温度升高的协同影响。更广泛的影响：这项拟议的研究将提供有关海洋酸化和变暖过程如何影响海洋浮游植物的机制信息。此外，博士后研究员和研究生将接受培训和支持。该项目还将与鹰眼研究所和保留区受托人合作，开展一项外联方案，让来自马萨诸塞州新贝德福德的夏季少数民族学生接触海洋学和环境科学。

In recent years, a number of studies have demonstrated significant impacts of ocean acidification on the physiology of marine phytoplankton. While the most well-known are studies that have focused on calcifying organisms, there have also been studies on noncalcifying phytoplankton, such as marine cyanobacteria and diatoms. Three particularly notable observations include: 1) increased growth and nitrogen fixation rates with acidification in marine nitrogen fixing cyanobacteria, 2) differences in response between the two most abundant marine cyanobacteria groups, Prochlorococcus and Synechococcus, where the growth of the latter responded positively to the acidification while the former did not, and 3) an increased level of iron stress in marine diatoms and a coccolithophore due to decreased iron availability upon lowered pH and the resultant shift in complexation chemistry. Together these suggest that ocean acidification has the potential for causing large shifts in: phytoplankton community composition, the sensitivity of this community to iron availability, and the marine nitrogen biogeochemical cycle. In this project, a research team at the Woods Hole Oceanographic Institution will investigate physiological mechanisms set into motion by the environmental stimuli associated with ocean acidification by quantifying changes in the proteome of four marine phytoplankton species: the abundant cyanobacteria Synechococcus and Prochlorococcus, the key nitrogen fixing cyanobacterium Crocosphaera, and an Antarctic diatom Nitzschia sp., in response to ocean acidification. In recent years, the team has adapted and developed quantitative proteomic capabilities for marine microbes using liquid chromatography mass spectrometry systems. The approach has become virtually routine and could be applied to a variety of problems related to ocean acidification. In addition, because of the climatic link between ocean acidification and global warming, the synergistic influences of increasing temperature will also be studied.Broader Impacts: This proposed study will provide mechanistic information about how the processes of ocean acidification and warming influence marine phytoplankton. In addition, a Postdoctoral Investigator and Graduate Student will be trained and supported. The project will also feature an outreach program to expose summer minority students from New Bedford, Massachusetts to oceanography and environmental science in partnership with the Eagle Eye Institute and Trustees of the Reservations.