DISSERTATION RESEARCH: Mechanisms of Anoxia Tolerance in Marsh Grasses in the Genus Spartddina (Poaceae)

论文研究：大米草属（禾本科）沼泽草的耐缺氧机制

• 批准号: 0508833
• 负责人: Raymond Lee
• 金额: --
• 依托单位: Washington State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-07-01 至 2006-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0508833&HistoricalAwards=false
• 关键词: DISSERTATION; RESEARCH; Mechanisms; Anoxia; Tolerance

AbstractAll higher plants depend on oxygen for cellular respiration. Under waterlogged conditions, oxygen is displaced from soil and usually is not sufficient to support aerobic respiration. Therefore, it is in the interest of wetland plants to lower aerobic demand and provide oxygen to submerged tissues. Many wetland plants have been shown to transport atmospheric oxygen internally to support respiration in submerged tissues. However, oxygen transport rates have not previously been compared between species of different flooding tolerances. Additional physiological factors, especially aerobic respiration rates and sulfide sensitivity, may also account for differences in flood tolerance but have not been investigated in wetland plants. Work is proposed to investigate the physiological basis of anoxia tolerance in a group of saltmarsh plants. Spartina is a small genus (about 15 species) in the grass family that grows in a wide range of habitats, including low intertidal marsh, high intertidal marsh, and freshwater areas. A comprehensive survey will be performed on the genus to elucidate the physiological mechanisms conferring success in anoxic low intertidal areas. In the proposed research, rates of internal oxygen transport will be measured and compared across Spartina species. Respiration rates will also be measured, along with aerobic and anaerobic respiration enzyme activities, and sulfide sensitivity across species. Knowledge of the relevant anoxia tolerance mechanisms may help understand the ecology of a dominant member of saltmarsh communities. The work is expected to help correctly identify mechanisms of flooding tolerance and estuarine zonation as well as provide a clear characterization of high intertidal and low intertidal estuarine functional types. This knowledge may later become useful in managing plants subjected to waterlogging conditions or to genetically engineer more flooding-tolerant crops.

摘要所有高等植物都依赖氧气进行细胞呼吸。在淹水的条件下，氧气从土壤中转移出来，通常不足以支持有氧呼吸。因此，降低需氧需求，为沉水组织提供氧气，符合湿地植物的利益。许多湿地植物已被证明在内部运输大气中的氧气，以支持水下组织的呼吸。然而，以前还没有对不同耐淹能力的物种之间的氧气传输速率进行比较。其他生理因素，特别是好氧呼吸速率和硫化物敏感性，也可能解释耐洪性的差异，但尚未在湿地植物中进行调查。对盐沼植物耐缺氧的生理基础进行了研究。大米草属是草科的一个小属(约15种)，生长在各种生境中，包括低潮间带沼泽、高潮间带沼泽和淡水区。将对该属进行全面的调查，以阐明在缺氧的低潮间带成功的生理机制。在这项拟议的研究中，将测量和比较不同种大米草的内部氧气运输速率。还将测量呼吸速率，以及好氧和厌氧呼吸酶活性，以及不同物种对硫化物的敏感性。对相关耐缺氧机制的了解可能有助于理解盐沼群落优势成员的生态。预计这项工作将有助于正确识别耐洪机制和河口分区，并提供高潮间带和低潮间带河口功能类型的明确特征。这一知识以后可能会对管理遭受内涝条件的植物或从基因工程中培育出更耐淹的作物有用。