Delineating the Roles of Rising CO2 and Temperature on Flowering Time and Plant Carbon Gain across Pre-Industrial Through Future Conditions
EMSL Project ID
47814
Abstract
Since the Industrial Revolution began (200 years ago), atmospheric [CO2] has increased from 270 to 390 ppm (44% increase), and average global temperatures have risen by 0.76 degrees C. In the future, [CO2] will likely reach 700 ppm by the end of this century, and global temperatures are expected to continue rising. Flowering time has a large influence on plant carbon gain and evolutionary processes and has been used as a major proxy for detecting the effects of climate change on plants. A variety of field studies have documented flowering times during recent, warmer decades relative to earlier, cooler decades. Although a number of plant species exhibit earlier flowering during recent warmer periods, this response is far from universal (only 5-37% of species), and some species even exhibit later flowering during warmer periods. Therefore, there are clearly effects of climate change on flowering time that are poorly understood at the growth, physiological, and molecular levels.The vast majority of field surveys have attributed earlier flowering (when it does occur) to increasing temperature, while ignoring the potential role of rising [CO2]. Perhaps rising [CO2] is rarely considered because it is confounded with rising temperature in natural systems. Ignoring this factor may prove problematic, however, since 57% of wild species and 62% of crop species exhibited altered flowering times when grown at elevated (700 ppm) versus modern (350 ppm) [CO2] (with no change in temperature). In addition, the effects of rising [CO2] on flowering time can be as large or larger as corresponding effects of temperature.
Using Arabidopsis genotypes from diverse locations, we found that increasing [CO2] between the pre-industrial and modern period accelerated flowering times, while the addition of increasing temperature actually eliminated this response (producing no change in flowering time). This was due to a systemic increase in plant size at flowering in the modern condition relative to the pre-industrial condition. This result questions our understanding of climate change effects on flowering time and may help to explain why more species are not exhibiting accelerated flowering times over the last century. In addition, we observed an explosion in variation for flowering time among Arabidopsis genotypes grown between modern and future conditions, which would be expected to have differential effects on whole-plant carbon gain, as well as evolutionary consequences. The overall goals of our proposed research are (1) to fully delineate the effects of rising [CO2] and temperature on flowering time across pre-industrial through future conditions, and (2) to better understand the growth, physiological, and molecular mechanisms that control flowering time and carbon gain in response to rising [CO2] and temperature. Moreover, by collaborating with EMSL scientists, this work will allow us to achieve the ultimate goal of linking transcriptome and metabolomic information to construct a model for understanding how climate change factors interact to influence flowering time and carbon gain across a full range of anthropogenic effects from the pre-industrial period through the future.
Project Details
Project type
Large-Scale EMSL Research
Start Date
2013-10-01
End Date
2014-09-30
Status
Closed
Released Data Link
Team
Principal Investigator
Team Members