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

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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.