Photosynthesis and Phloem Anatomy

光合作用和韧皮部解剖学

• 批准号: 0841546
• 负责人: Barbara Demmig-Adams
• 金额: $ 48.62万
• 依托单位: University of Colorado at Boulder
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-05-01 至 2013-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0841546&HistoricalAwards=false
• 关键词: Photosynthesis; Phloem; Anatomy

The proposed work seeks to improve the currently incomplete understanding of factors that determine, and may limit, plants' maximal rates of photosynthesis and productivity. By combining physiological and anatomical assessments, it will be tested whether there is a fundamental relationship between the maximum rate of plant photosynthesis and specific anatomical features that may be determinants of the capacity of leaves' sugar-exporting (phloem) vessels. Sugar export may sometimes present a bottleneck to carbon distribution throughout the plant and thus to plant productivity. In particular, leaf loading vein density and the ratio of loading cells per exporting phloem vessel will be assessed in species with different mechanisms of phloem loading. If a relationship between photosynthetic capacity and phloem features can be established, these features will be available to: (i) identify plant species and varieties with superior photosynthetic performance and productivity; (ii) inform future engineering efforts directed at manipulating these anatomical features to enhance plant productivity. It will furthermore be established whether features such as high loading vein density are associated with enhanced productivity under dry conditions and/or cool temperatures. If such an advantage can be established, this will aid in the selection of plants with superior productivity in warm/arid regions that are expanding under global climate change and at higher latitudes and altitudes into which crop cultivation is expanding under the present global warming trend and where plants will experience seasonal exposure to colder than usual temperatures. The knowledge gained from this work will aid in the effort to maintain, and improve, crop productivity as well as carbon sequestration, which are urgent goals given the burgeoning human population as well as the current and projected impact of climate change. Furthermore, the PIs will utilize their existing connections to recruit students from diverse backgrounds into the proposed research and resulting publication/dissemination efforts as well as for outreach efforts. Lastly, the PIs are planning to continue their publication activity in venues reaching a broad audience including non-specialists.

这项拟议的工作旨在改善目前对决定并可能限制植物最大光合作用速率和生产力的因素的不完全理解。通过结合生理和解剖学评估，将测试植物光合作用的最大速率与特定的解剖特征之间是否存在基本关系，这些特征可能是决定叶片输出糖(韧皮部)导管能力的因素。糖的出口有时会对整个植物的碳分配造成瓶颈，从而影响植物的生产力。特别是，叶片装载脉密度和每个输出韧皮部导管的装载细胞比率将在具有不同韧皮部装载机制的物种中进行评估。如果能够确定光合作用能力和韧皮部特征之间的关系，这些特征将可用于：(I)识别具有更好的光合作用性能和生产力的植物物种和品种；(Ii)为未来旨在操纵这些解剖特征以提高植物生产力的工程努力提供信息。此外，还将确定诸如高加载静脉密度之类的特征是否与在干燥条件和/或凉爽温度下提高生产率有关。如果能够建立这样的优势，这将有助于在全球气候变化下正在扩张的温暖/干旱地区以及在当前全球变暖趋势下作物种植正在扩大到的更高纬度和海拔地区选择具有优越生产力的植物，这些地区的植物将经历比平时更低的季节性温度。从这项工作中获得的知识将有助于努力维持和提高作物生产力和碳固存，鉴于人口的迅速增长以及气候变化目前和预计的影响，这些都是紧迫的目标。此外，私人投资机构将利用现有的联系，招募来自不同背景的学生参加拟议的研究和由此产生的出版/传播工作，以及进行外联工作。最后，私人投资总监计划继续在场地进行出版活动，接触到包括非专业人士在内的广大受众。