En-Gen: A functional genomic analysis of how a major calcifying phytoplankter responds to ocean acidification predicted for the end of the century

En-Gen：对主要钙化浮游植物如何应对本世纪末预测的海洋酸化进行功能基因组分析

• 批准号: 0723908
• 负责人: Edward Carpenter
• 金额: $ 118.47万
• 依托单位: San Francisco State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-10-01 至 2012-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0723908&HistoricalAwards=false
• 关键词: En; Gen; functional; genomic; analysis

The coccolithophore Emiliania huxleyi is the most abundant calcifying phytoplankton species in the world's oceans. Due to its abundance and broad range of occurrence, deep-sea export of its CaC03 coccoliths plays a significant role in the oceans alkalinity balance, and in turn, air-sea CO2 exchange. Since the start of the industrial age, atmospheric partial pressure of CO2 (pCO2) has steadily increased due to fossil fuel combustion and land use change, and is projected to reach 750 ppm by the end of this century. As a consequence, both seawater pH and carbonate ion concentration are expected to drop significantly relative to pre-industrial times. Calcifying organisms are sensitive to changes in carbonate ion concentration, however, neither the extent of this sensitivity, nor its physiological basis, are well understood. The purpose of this project is to examine the mechanism (s) by which E. huxleyi physiologically acclimates and adapts to changes in its environment in order to understand the impact of changes in seawater carbonate chemistry on this important planktonic calcifying organism. Cells from two genetically distinct ecotypes will be cultured in chemostats at present day and projected year 2100 levels of pCO2 under nitrogen or phosphorus limitation. Both short- (2 week) and long-term (2 year) experiments will be conducted to investigate acclimation and adaptation responses to changes in carbonate chemistry, respectively. In each experiment, patterns of gene expression will be investigated using a microarray that has been developed by the E. huxleyi genome sequencing projects. Gene expression will be analyzed as a function of physiological performance (photosynthesis vs. irradiance), calcification rates and cellular nutrient content. The results of this project will generate a novel set of candidate biomarker genes for analysis of the environmental physiology of coccolithophorids and contribute to a better prediction of the role of E. huxleyi in air-sea CO2 exchange in the next century. Since E. huxleyi is a globally distributed organism that frequently forms massive blooms, there are numerous investigators studying it and this research will therefore be of broad interest to the scientific community. Graduate students, a postdoctoral investigator, and high school students will be trained during this project and underrepresented minorities will participate in this research project. Public outreach on this research will be conducted through the Romberg Tiburon Center and the NSF-funded Bay Area Discovery Museum.

Coccolithore Emiliania Huxleyi是世界海洋中最丰富的钙化浮游植物物种。 由于其丰度和广泛的发生范围，其CAC03 Coccoliths的深海出口在海洋碱度平衡中起着重要作用，而Air-Sea CO2交换则起着重要作用。 自工业时代开始以来，由于化石燃料燃烧和土地利用变化，二氧化碳的大气部分压力（PCO2）稳步增加，预计到本世纪末，二氧化碳（PCO2）的大气压力将达到750 ppm。 因此，相对于工业前时代，海水pH和碳酸盐离子浓度均有明显下降。 钙化生物对碳酸盐离子浓度的变化敏感，但是，这种敏感性的程度或其生理基础都没有充分了解。 该项目的目的是检查E. huxleyi在生理上适应并适应其环境变化的机制，以了解海水碳酸盐化学变化对这种重要的浮游钙化生物体的影响。 在氮或磷限制下，来自两个遗传学不同生态型的细胞将在当今的化学稳定剂中培养，并预计2100年的PCO2水平。 短期（2周）和长期（2年）的实验都将分别研究对碳酸盐化学变化的适应和适应反应。 在每个实验中，将使用E. huxleyi基因组测序项目开发的微阵列研究基因表达的模式。 基因表达将作为生理性能（光合作用与辐照度），钙化速率和细胞营养含量的函数进行分析。 该项目的结果将产生一组新型的候选生物标志物基因，以分析o​​ccolophophophorids的环境生理学，并在下个世纪有助于更好地预测Huxleyi在气海CO2交换中的作用。由于Huxleyi是一种经常形成大量盛开的全球分布生物，因此有许多研究人员正在研究它，因此这项研究将引起科学界的广泛兴趣。 研究生，博士后调查员和高中生将在该项目中接受培训，而代表性不足的少数民族将参加该研究项目。 这项研究的公共活动将通过Romberg Tiburon中心和NSF资助的湾区发现博物馆进行。