The Interactive Effects of Light & Nutrient Source on the Molecular Regulation of Nitrogen Assimilation, Photochemistry, & Growth of Two Raphidophyte Species from DE's Inla

光的交互效果

• 批准号: 0745102
• 负责人: Kathryn Coyne
• 金额: $ 45万
• 依托单位: University of Delaware
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-04-15 至 2012-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0745102&HistoricalAwards=false
• 关键词: Interactive; Effects; Light; & Nutrient

Understanding the environmental and biological factors that contribute to phytoplankton population dynamics is a central goal in the study of aquatic ecology. Although much is known about how individual variables such as nitrogen and light impact phytoplankton, little is known about the interactive effects of these parameters. The utilization of nitrate, in particular, is largely controlled by the amount of light absorbed. Nitrate reductase, an enzyme involved in assimilating nitrate, has also been shown to prevent damage to photosynthesis by siphoning off excess light energy during periods of intense sunlight. Two harmful algal species, Heterosigma akashiwo and Chattonella subsalsa, often bloom in Delaware's inland bays. They make excellent subjects for investigating the interactive effects of nutrients and light, as they both bloom during periods of high light exposure yet prefer different sources of nitrogen. For this project, rates of nitrogen uptake will be determined at different light levels for each species. The roles of light, temperature and nutrient availability in the regulation of nitrate reductase will be examined, and the impact of nitrate reductase and other biochemical pathways on photosynthesis will be evaluated. This research will examine links between carbon and nitrogen utilization at multiple levels, from expression of carbon- and nitrogen- regulated genes, to photobiology, to shifts in natural algal communities. Results of this work will contribute to the development of ecological models of harmful algal bloom development and a better characterization of the primary factors that impact phytoplankton ecology. This research will directly involve the training and education of graduate and undergraduate students. Dissemination of research results to the public is planned through both print and lecture presentations and an interactive website targeting middle and high school students.

了解影响浮游植物种群动态的环境和生物因素是水生生态学研究的中心目标。虽然人们对氮和光照等单个变量如何影响浮游植物知道得很多，但对这些参数的交互影响却知之甚少。尤其是硝酸盐的利用，在很大程度上受制于吸收的光量。硝酸还原酶是一种参与同化硝酸盐的酶，也被证明可以在强烈的阳光下吸收多余的光能，从而防止光合作用受到损害。两种有害的藻类，赤潮异弯藻和盐下查托氏藻，经常在特拉华州的内陆湾繁殖。它们是研究营养和光照相互作用的极佳对象，因为它们都在高光照射期间开花，但对不同的氮源有不同的偏好。对于这个项目，将确定每个物种在不同光照水平下的氮素吸收速率。将研究光、温度和养分有效性在硝酸还原酶调节中的作用，并将评估硝酸还原酶和其他生化途径对光合作用的影响。这项研究将研究碳和氮在多个水平上的利用之间的联系，从碳和氮调节基因的表达，到光生物学，再到自然藻类群落的变化。这项工作的结果将有助于开发有害藻华发展的生态模型，并更好地描述影响浮游植物生态的主要因素。这项研究将直接涉及到研究生和本科生的培养和教育。计划通过印刷品和讲座演示以及针对初中生和高中生的互动网站向公众传播研究成果。