Collaborative Research: Linking physiological and molecular aspects of diatom silicification in field populations

硅藻是一种单细胞真核光合自养生物，是海洋中最具生态学意义和功能多样性的生物之一。除了贡献全球初级生产力的五分之一，硅藻也是海洋中最大的硅化生物群。因此，硅藻在碳和硅（Si）循环之间形成关键的连接。该项目的目标是了解天然硅藻种群中硅化过程的分子调控，以更好地了解控制海洋硅藻生产力的过程。通过培养研究和两次研究航行，本研究将硅吸收和二氧化硅生产的经典测量与硅化相关基因（SiRG）和蛋白质表达的分子和生物化学分析相结合。拟议的美国西海岸外的巡航轨道将以硅和铁（Fe）浓度梯度为目标，目标如下：2）将SiRG表达模式与Si浓度、硅吸收动力学和二氧化硅产生速率相关联，3）开发一种将摄取动力学和二氧化硅产生标准化为SiRG表达水平的方法，作为硅藻活性和生长的更准确量度，4）表征二氧化硅生产和SiRG表达的昼夜周期性。智力优势：据估计，硅藻每年处理240太摩尔的生物二氧化硅，每个硅分子在被出口到深海之前通过硅藻循环39次。几十年的海洋学和实地研究提供了详细的了解硅的吸收和二氧化硅生产在自然种群的动态，但影响硅化过程的因素，需要进一步了解硅和碳通量在海洋中的调节分子的理解。表征硅化的遗传潜力将提供新的信息的因素，调节硅藻的分布和影响原位硅吸收率和二氧化硅生产。这项研究预计将提供重要的信息硅化在自然种群的分子调控和Si限制在sea.Broader影响的生理基础：该项目融合了生理学，分子生物学和生物化学与海洋生态学和海洋学的概念，提供了一个机会，研究人员与不同的利益进行互动。该项目提供了一个机会，为女性研究人员获得第一次PI的经验，并在同一时间，为本科生和研究生提供了优秀的动手，跨学科的培训。此外，服务不足和代表性不足的本科生将参与实验室和实地研究。研究活动还将与罗格斯大学和加州大学圣巴巴拉分校的既定外展计划对接，以开发新的方法，将实地工作产生的科学主题和数据集转化为针对K-12教育工作者，K-12学生和本科生的创新教材。高级人员还将致力于开发教育单元，以便在网上和专业发展讲习班上分发。

Diatoms, unicellular, eukaryotic photoautotrophs, are among the most ecologically successful and functionally diverse organisms in the ocean. In addition to contributing one-fifth of total global primary productivity, diatoms are also the largest group of silicifying organisms in the ocean. Thus, diatoms form a critical link between the carbon and silicon (Si) cycles. The goal of this project is to understand the molecular regulation of silicification processes in natural diatom populations to better understand the processes controlling diatom productivity in the sea. Through culture studies and two research cruises, this research will couple classical measurements of silicon uptake and silica production with molecular and biochemical analyses of Silicification-Related Gene (SiRG) and protein expression. The proposed cruise track off the West Coast of the US will target gradients in Si and iron (Fe) concentrations with the following goals: 1) Characterize the expression pattern of SiRGs, 2) Correlate SiRG expression patterns to Si concentrations, silicon uptake kinetics, and silica production rates, 3) Develop a method to normalize uptake kinetics and silica production to SiRG expression levels as a more accurate measure of diatom activity and growth, 4) Characterize the diel periodicity of silica production and SiRG expression.Intellectual Merit: It is estimated that diatoms process 240 Teramoles of biogenic silica each year and that each molecule of silicon is cycled through a diatom 39 times before being exported to the deep ocean. Decades of oceanographic and field research have provided detailed insight into the dynamics of silicon uptake and silica production in natural populations, but a molecular understanding of the factors that influence silicification processes is required for further understanding the regulation of silicon and carbon fluxes in the ocean. Characterizing the genetic potential for silicification will provide new information on the factors that regulate the distribution of diatoms and influence in situ rates of silicon uptake and silica production. This research is expected to provide significant information about the molecular regulation of silicification in natural populations and the physiological basis of Si limitation in the sea.Broader Impacts: This project blends concepts in physiology, molecular biology, and biochemistry with marine ecology and oceanography, providing an opportunity for researchers with diverse interests to interact. This project provides an opportunity for a female researcher to get first-time PI experience and, at the same time, provides excellent hands-on, cross-disciplinary training for undergraduate and graduate students. In addition, underserved and underrepresented undergraduate students will be involved in both lab and field-based research. Research activities will also interface with established outreach programs at both Rutgers and UC Santa Barbara to develop novel methods for translating scientific themes and data sets generated from field work into innovative teaching materials aimed at K-12 educators, K-12 students, and undergraduates. Senior personnel will also work to develop educational units to be distributed online and in professional development workshops.