Submitted to: Plant Cell and Environment
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: April 1, 2010
Publication Date: July 1, 2010
Citation: Betzelberger, A.M., Gillespie, K.M., Mcgrath, J.M., Koester, R.P., Nelson, R.L., Ainsworth, E.A. 2010. Effects of Chronic Elevated Ozone Concentration on Antioxidant Capacity, Photosynthesis and Seed Yield of 10 Soybean Cultivars. Plant Cell and Environment. 33(9):1569-1581. Available: doi: 10.1111/j.1365-3040.2010.02165.x. Interpretive Summary: Rising ground-level ozone in the United States is estimated to cost $1-3 billion in crop losses annually, making ozone the most damaging air pollutant to plants. In the future, ozone levels are expected to increase, causing even greater losses to crop production. This study addressed the ozone problem by investigating the response of ten different soybean varieties to ozone. On average, high ozone reduced soybean yields by 23% in 2007 and by 13% in 2008, and there were significant differences in ozone tolerance among the different varieties. A number of physiological and biochemical traits were predictive of seed yield, suggesting that soybean breeders could use these traits to screen a broader collection of soybean germplasm for ozone tolerance.
Technical Abstract: Crops losses due to ozone (O3) in the United States are estimated to cost $1-3 billion annually, making it the most damaging air pollutant to plants. This challenge to crop production is expected to increase as O3 levels rise over the next half-century, particularly in sensitive crop species like soybean. This study tested the hypothesis that there is significant cultivar variation in the response of soybean seed yield to growth at elevated [O3], and identified physiological and biochemical markers for O3 tolerance. Ten different genotypes of soybean were grown at elevated [O3] from germination through maturity at the Soybean Free Air Concentration Enrichment (SoyFACE) facility in 2007 and six genotypes were also grown in 2008. Photosynthetic gas exchange, leaf area index (LAI), leaf chlorophyll content and antioxidant capacity were monitored throughout the growing season in order to determine if changes in these parameters could be used to predict the sensitivity of seed yield to elevated [O3]. Cultivar differences in response to O3 were observed in seed yield, net carbon assimilation (A), stomatal conductance to water vapor (gs), LAI, leaf chlorophyll content, and, during reproductive growth, total antioxidant capacity. We identified a number of potential predictive traits correlated with variation in seed yield. There is potential to use these traits to screen soybean germplasm collections for O3 tolerance.