Light Regulation of Carbon Partitioning and Growth of Eelgrass

海草分布在除最极地海洋外的所有海洋的边缘，是世界上一些最多产的植物群落的基础。它们在养分循环、沉积物沉积和结合、为大型和多样化的动物提供栖息地等方面发挥着重要的生态作用，并对近岸食物网做出了重要贡献。大叶藻，Zostera marina，通常在近岸水域的单型林分中发现，其特点是光照有限，存在缺氧，富含有机物的沉积物。大叶藻栖息地的本质对地下组织施加了昼夜且经常长期的缺氧/缺氧，并严重限制了碳的获得。大叶藻承受这些条件并从这些条件中恢复的能力必须是其生态成功的基础。正在进行的研究已经开始研究大叶藻在这些栖息地成功生长的生理和生化机制。该研究项目将建立在先前的研究基础上，并推进当前的理解，超越对整个植物碳预算的简单计算，到指示植物对海底光环境和缺氧沉积物的综合反应的生化和分子特征。本研究将探讨海底光照条件控制滨海Zostera生存深度、生长和生产力的基本机制，并阐明该物种的主要生理、生化和分子特征，以确保其在沿海环境中生态成功。特别是，本项目将研究Zostera marina芽和根之间碳分配的控制，并启动分子检测，以确定翻译和转录事件在调节根对昼夜和长时间缺氧反应中的相对重要性。该项目应提供控制大叶藻分布和碳分配策略的主要因素的必要机制理解，以便将这种复杂程度纳入该物种生长和生产力的预测数值模型。从这些研究中获得的知识不仅将促进我们对控制海洋底栖生物生产力的因素的理解，有助于我们对植物功能的适应机制的基本理解，而且还将为水下大型植物的健全和知情管理提供必要的信息。

Seagrasses are distributed along the margins of all but the most polar seas and form the basis of some of the most productive plant communities in the world. They play important ecological roles in nutrient cycling, sediment deposition and binding, provision of habitat for a large and diverse fauna, and contribute significantly to nearshore food webs. Eelgrass, Zostera marina, is found typically in monotypic stands in nearshore waters characterized by light limitation and the presence of anoxic, organic-rich sediments. The very nature of eelgrass habitats imposes diurnal and often prolonged hypoxia/anoxia on subterranean tissues and severe restrictions on carbon gain. The ability of eelgrass to withstand and recover from these conditions must underlie its ecological success. Ongoing studies have begun to examine the physiological and biochemical mechanisms responsible for the success of eelgrass in these habitats. This research project will build on prior research and advance current understanding, beyond a simple accounting of whole plant carbon budgets, to the biochemical and molecular features that dictate integrated plant responses to submarine light environments and anoxic sediments. This research will address the fundamental mechanisms by which submarine light regimes control the survival depth, growth and productivity of Zostera marina, and elucidate the primary physiological, biochemical and molecular features of this species that ensure its ecological success in littoral environments. In particular, this project will investigate the controls on carbon partitioning between shoots and roots in Zostera marina, and initiate molecular examinations to determine the relative importance of translational and transcription events in regulating root responses to diurnal and prolonged anoxia. This project should provide the needed mechanistic understanding of the major factors that control the distribution and carbon allocation strategies of eelgrass, so that this level of sophistication can be incorporated into a predictive numerical model of growth and productivity for this species. The knowledge gained form these studies will not only advance our understanding of factors that control marine benthic productivity and contribute to our basic understanding of the adaptive mechanisms that function in plants, but provide information essential to sound and informed management of submerged macrophytes.