Physiological and Molecular Mechanisms Controlling Altered Flowering Times at Elevated [CO2]
EMSL Project ID
48397
Abstract
Shifts in flowering time in response to climate change can alter both the timing and amount of carbon that is cycling within ecosystems. Atmospheric CO2 concentration ([CO2]) has increased from 270 to 400 ppm since the industrial revolution began, and global temperatures have risen by 0.85 degrees C. By the end of this century, [CO2] is expected to reach 700 ppm, with further increases in temperature. These factors have already influenced flowering time and are expected to have even greater impacts in the future. Therefore, it is critical that we understand the basic mechanisms that drive altered flowering times under future climate change scenarios.To date, the majority of climate change studies have focused on the effects of rising temperature and have typically indicated an acceleration of flowering times in experimental and field studies. On the other hand, the direct and simultaneous effects of rising [CO2] have received less attention, but can be as large (or larger) as temperature effects, producing both delays and accelerations in flowering time (depending on species/genotype). Importantly, rising [CO2] is occurring on a global scale and therefore will affect plants in all terrestrial ecosystems, whereas temperature change varies at the regional level. We found in a large survey that over half of plant species exhibit major alterations in flowering time when grown at elevated (700 ppm) versus current (400 ppm) [CO2]. Thus, identifying the basic mechanisms that explain altered flowering times at elevated [CO2] via plant model systems is a critical component of understanding the long-term responses of plants to climate change.
The overall goal of our proposed research is to determine the physiological and molecular mechanisms that control the effects of elevated [CO2] on flowering time. In previous work with Arabidopsis thaliana, we identified flowering genes that were sensitive to elevated [CO2], and we defined a chromosomal region (QTL) that drives altered flowering time at elevated [CO2]. Recent work by others has shed light on the sensing of carbohydrate status within plants, which subsequently affects flowering time. Coupled with that, it is well known that elevated [CO2] alters the carbohydrate status of plants. Thus, we operate under the hypothesis that variations in flowering time at elevated [CO2] may reflect a disconnect between total leaf carbohydrate levels and metabolites that act as triggers to initiate flowering programs. We address two specific aims:
1. How do leaf physiology, leaf metabolite profiles, and gene expression correlate with altered flowering time in selected and control Arabidopsis genotypes showing differential responses to elevated [CO2]?
2. Do field-collected genotypes of Arabidopsis exhibit similar patterns of metabolite profiles/sugar signaling and gene expression that correlate with flowering time differences at elevated [CO2]?
To address these aims, we require experimental and computational methods that are unique to EMSL (e.g., mass spectrometry, NMR, and RNA-Seq), as well as expertise offered by EMSL scientists. Through this collaboration, we will gain a more thorough understanding for how a changing global factor is influencing plant developmental programs with subsequent effects on carbon cycling and potentially biofuel production.
Project Details
Project type
Large-Scale EMSL Research
Start Date
2014-10-01
End Date
2017-09-30
Status
Closed
Released Data Link
Team
Principal Investigator
Team Members
Related Publications
Walker LR, DW Hoyt, SM Walker, JK Ward, CD Nicora, and AK Bingol. 2016. "Unambiguous Metabolite Identification in High-throughput Metabolomics by Hybrid 1D 1H NMR/ESI MS1 Approach." Magnetic Resonance in Chemistry 54(12):998-1003. doi:10.1002/mrc.4503