|Leakey, Andrew D|
|Ainsworth, Elizabeth - Lisa|
Submitted to: American Society of Plant Biologists
Publication Type: Abstract Only
Publication Acceptance Date: 4/1/2006
Publication Date: 8/5/2006
Citation: Gillespie, K.M., Chae, J.M., Leakey, A.B., Ainsworth, E.A. 2006. How will future elevated levels of CO2 and O3 affect antioxidant metabolism in soybean? [abstract]. American Society of Plant Biologists. Paper No. P02014. Interpretive Summary:
Technical Abstract: Immense research efforts have been devoted to characterizing the effects of global change on plants, particularly elevated concentrations of CO2 and O3. While the physiological responses of plants to elevated [CO2] and [O3] have been well characterized, the molecular and biochemical mechanisms by which physiology is affected are still mostly unknown. A key process that remains to be understood is the oxidative stress response. Once ozone enters the leaf through the stomata, it is immediately converted into various reactive oxygen species (ROS). This leads to oxidation and loss of protein function in internal tissue. A coordinated set of enzymes and metabolites, called the antioxidant system, quenches these harmful ROS. While the antioxidant system is up regulated in plants grown under elevated [O3], these plants still incur oxidative damage. Research regarding responses of the antioxidant system to elevated [CO2] is ambiguous. In some studies, antioxidants are down regulated, and in other studies they are up regulated. How the combination of elevated [CO2] and [O3] affect antioxidant metabolism is unknown. The aim of our research is to investigate how antioxidant capacity of soybean (Glycine max Merr.) is affected by season-long treatment with elevated [CO2] (550 ppm) and [O3] (1.2 x ambient). We have taken samples at 6 developmental stages throughout the 2005 growing season at the Soybean Free Air gas Concentration Enrichment (SoyFACE) facility, and have analyzed them for total antioxidant capacity. These experiments describe how the antioxidant capacity of soybean leaves may differ in atmospheric conditions predicted for 2050. Future work will link changes in the activity of anti-oxidant enzymes and expression of transcripts to changes in total antioxidant capacity.