Plant Evolution at Elevated CO2: Physiological and Genetic Mechanisms Controlling Developmental Timing

[CO2]升高条件下植物的进化控制发育时间的生理和遗传机制joy K. Ward (PI)，堪萨斯大学生态和进化生物系john K. Kelly (Co-PI)，堪萨斯大学本研究的目的是确定大气二氧化碳浓度升高对拟南芥田间采集和选择的基因型发育时间的影响，并阐明控制这种反应的遗传和分子机制。未来，全球变化因素将对陆地生态系统的功能和生产力产生深远影响。与不同地区的温度和降水不同，大气中的二氧化碳正在全球范围内上升，并正在为植物产生新的碳可用性水平。确定植物适应二氧化碳上升的机制并了解这些反应将如何影响植物未来的功能和生产力是至关重要的。在快速变化的环境中，植物对二氧化碳浓度升高的反应可能决定了长期的进化过程，但这些反应受到的关注相对较少。为了解决这一问题，研究人员选择了拟南芥的特定遗传品系，预测在未来70-100年二氧化碳浓度升高的情况下，拟南芥的种子产量会增加。对选择有明显反应的品系，在二氧化碳浓度升高（700 ppm）和当前（380 ppm）的条件下生长时，开花时间出现中断，而随机选择的对照基因型则没有这种反应。这代表了在进化相关背景下研究植物对高浓度二氧化碳的发育反应的一个前所未有的系统。本研究旨在实现以下目标：(1)确定二氧化碳浓度升高对来自北美和欧洲不同地区的拟南芥植物开花时间的影响；(2)确定在高二氧化碳浓度下选择高产的拟南芥基因型延迟开花的染色体区域；(3)表征在高二氧化碳浓度下影响开花时间的基因的影响。本研究具有高度的跨学科性质，因此在分子生物学、数量遗传学和生理生态学等领域提供了良好的培训机会。该项目将包括代表性不足的群体的参与，包括来自哈斯凯尔印第安民族大学和堪萨斯大学生物科学倡议项目的学生，该项目增加了少数民族在生物科学领域的代表性。最后，这项研究将通过开发遗传植物资源使科学界受益，这些资源将提供给其他对了解植物如何适应未来大气中二氧化碳浓度上升感兴趣的研究人员。

Plant Evolution at Elevated [CO2]: Physiological and Genetic Mechanisms Controlling Developmental TimingJoy K. Ward (PI), University of Kansas, Department of Ecology and Evolutionary BiologyJohn K. Kelly (Co-PI), University of Kansas, Department of Ecology and Evolutionary BiologyThe purpose of the proposed research is to determine the effects of elevated atmospheric carbon dioxide on the developmental timing of field-collected and selected genotypes of Arabidopsis thaliana and to elucidate the genetic and molecular mechanisms that control this response. Global change factors will have profound effects on the functioning and productivity of terrestrial ecosystems in the future. Unlike temperature and precipitation that vary across regions, atmospheric carbon dioxide is rising on a global scale and is producing novel levels of carbon availability for plants. It is critical to define the mechanisms for plant adaptation to rising carbon dioxide and to understand how these responses will influence plant functioning and productivity in the future. Changes in the developmental timing of plants in response to elevated carbon dioxide are likely to dictate long-term evolutionary processes in a rapidly changing environment, yet these responses have received relatively little attention. To address this issue, specific genetic lines of Arabidopsis have been selected for increased seed production at elevated carbon dioxide predicted for 70-100 years in the future. Lines showing pronounced responses to selection exhibit disruptions in time to flowering when grown at elevated (700 ppm) versus current (380 ppm) carbon dioxide concentrations, whereas randomly selected control genotypes do not exhibit this response. This represents an unprecedented system for studying the developmental responses of plants to elevated carbon dioxide in an evolutionarily relevant context. This research addresses the following objectives: (1) to determine the effects of elevated carbon dioxide on time to flowering for Arabidopsis plants from different locations throughout North America and Europe, (2) to identify chromosomal regions that confer delayed flowering for an Arabidopsis genotype that was selected for high performance at elevated carbon dioxide, and (3) to characterize the effects of genes that influence the timing of flowering at elevated carbon dioxide. The proposed research is highly inter-disciplinary in nature, and therefore offers excellent training opportunities in the fields of molecular biology, quantitative genetics, and physiological ecology. This project will include the participation of under-represented groups, including students from Haskell Indian Nations University and from the Bioscience Initiative program at the University of Kansas that increases the representation of minorities in the biological sciences. Finally, this research will benefit the scientific community through the development of genetic plant resources that will be made available to other researchers interested in understanding how plants will adapt to rising concentrations of atmospheric carbon dioxide in the future.