Elevated Atmospheric CO2 and Cytosolic Control of Leaf Isoprene Biogenesis

大气二氧化碳浓度升高和叶异戊二烯生物发生的胞质控制

• 批准号: 0543895
• 负责人: Richard Fall
• 金额: $ 52.56万
• 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: 2006
• 资助国家: 美国
• 起止时间: 2006-04-15 至 2010-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0543895&HistoricalAwards=false
• 关键词: Elevated; Atmospheric; CO2; Cytosolic; Control

Intellectual MeritThe emission of isoprene from the leaves of trees causes photochemical reactions in the lower atmosphere that lead to many important environmental consequences. For example, isoprene from trees contributes to the formation of tropospheric ozone pollution, an increase in the concentration of atmospheric methane, and the production of nitrogenous compounds that can harm human health and plant productivity. Past studies show that isoprene emissions from trees are inhibited by elevated atmospheric carbon dioxide (CO2) concentrations. This inihibition leads to the hypothesis that in the future, as the atmospheric CO2 concentration increases, the emission of isoprene from forest ecosystems will decrease. Current understanding of the physiological processes that control isoprene emission at elevated CO2 is inadequate for accurately predicting future isoprene emissions from forests. This project will improve our understanding of the processes that control isoprene emissions from leaves in an atmosphere of elevated CO2, and will focus on processes at the cellular level. The project tests the hypothesis that isoprene emissions are inhibited at elevated CO2 because of competition between the chloroplasts and the cytosol of the cell for carbon substrates. Experiments will focus on the response of the enzymes and processes known to be sensitive to increases in atmospheric CO2. The research will utilize advanced instrumentation and technologies to test the hypothesis that elevated atmospheric CO2 causes partial depletion of a chloroplast substrate needed for isoprene biosynthesis. Advanced instrumentation and technologies include proton transfer reaction mass spectrometry, and advanced biochemical techniques in enzyme purification and characterization. The research will be conducted with cottonwood (Populus) trees that are genetically transformed specifically for this study. Broader ImpactsThe studies will provide training opportunities for a postdoctoral student, and two graduate students. The project will also catalyze development of a unique course entitled, "Forest Biotechnology and the Environment." The research will foster the collaborative relationship between those at the University of Colorado, and those working with Professor Heinz Rennenberg at the Universitat Freiburg, Germany. Professors Monson and Fall participate in the Cooperative Institute for Research in Environmental Science (CIRES), that stimulates interdisciplinary research within and between the University of Colorado and the National Oceanic and Atmospheric Administration (NOAA).

从树叶中释放出的异戊二烯会在低层大气中引起光化学反应，从而导致许多重要的环境后果。例如，来自树木的异戊二烯有助于形成对流层臭氧污染，增加大气中甲烷的浓度，并产生可能损害人类健康和植物生产力的含氮化合物。过去的研究表明，树木的异戊二烯排放受到大气二氧化碳(CO2)浓度升高的抑制。这种抑制导致了这样的假设，即在未来，随着大气CO2浓度的增加，森林生态系统中异戊二烯的排放量将会减少。目前对二氧化碳升高时控制异戊二烯排放的生理过程的了解不足以准确预测未来森林的异戊二烯排放。这个项目将提高我们对在二氧化碳浓度升高的大气中控制树叶异戊二烯排放的过程的理解，并将重点放在细胞水平的过程上。该项目测试了一种假设，即在二氧化碳浓度升高时，异戊二烯的排放受到抑制，这是因为叶绿体和细胞胞质之间竞争碳底物。实验将重点放在已知对大气二氧化碳增加敏感的酶和过程的反应上。这项研究将利用先进的仪器和技术来测试大气中二氧化碳升高导致异戊二烯生物合成所需的叶绿体底物部分耗尽的假设。先进的仪器和技术包括质子转移反应质谱仪，以及酶纯化和表征方面的先进生化技术。这项研究将用专门为这项研究而进行的转基因杨树进行。更广泛的影响这些研究将为一名博士后和两名研究生提供培训机会。该项目还将促进一门名为“森林生物技术与环境”的独特课程的开发。这项研究将促进科罗拉多大学的学生和德国弗莱堡大学的海因茨·伦南伯格教授之间的合作关系。Monson和Fall教授参与了环境科学合作研究所(CIRES)，该研究所鼓励科罗拉多大学与美国国家海洋和大气管理局(NOAA)内部和之间的跨学科研究。