The effect of CO2-enriched atmospheres to producing of
allergenic pollen by ragweed
Background: The prevalence of allergic diseases has increased result from exposure to environmental pollutants. Aeroallergen exposure is associated with allergic rhinitis and asthma. Pollens have long been known to be a significant cause of allergic disease. Pollen in heavily polluted zones can express a larger amount of proteins described as being allergenic. In the presence of high CO2 concentrations and temperatures, plants increase their pollen output.
Method: Ragweed establishment: 1) Chamber study: Ten plants of ragweed were established in open-top chamber at different concentration of CO2 (380-400, 500-520, 600-620, 1000-1100ppm). 2) Field study: Beginning in March 2012 and 2014, a rural (Pocheon, Kyunggi-do, annual mean CO2: 230ppm) and urban (Kangnam, Seoul, annual mean CO2: 440ppm) locations were established. Seeds of common ragweed (Ambrosia artemisiifolia) and giant ragweed (A. trifida) were obtained from Daejin University from a common seed lot of ragweed. At final harvest, entire plants were collected. To determine qualitative changes in pollen, harvested pollen grains were suspended in 95% ethanol. The crude soluble pollen protein preparations were stored at -20°. Protein content of the extracts was quantified. Concentration of Allergens (common ragweed (Amb a 1) and giant ragweed(Amb t 5) was quantified through use of double sandwich ELISA.
RESULTS: 1) chamber study: 1) chamber study: Concentration of Amb a 1 was increased with increased CO2 Conc. (380-400, 500-520, 600-620, 1000-1100ppm: 18.4±5.0, 30.8±13.1, 42.5±11.2, 50.1±21.2 ng/mL), Concentration of Amb t 5 was increased with increased CO2 Conc. (380-400, 500-520, 600-620, 1000-1100ppm: 22.1±6.8, 36.3±11.6, 48.3±19.5, 64.6±21.3 ng/mL), 2) Field study: There were not significantly different between Pocheon (CO2 230ppm: 16.0±2.0ng/mL) and Seoul (CO2 440ppm: 20.3±8.6ng/mL) in Conc. of Amb a 1, also Pocheon (CO2 230ppm: 24.5±6.9ng/mL) and Seoul (CO2 440ppm: 28.3±6.2ng/mL) in Conc. of Amb t 5, though Conc. of Amb a 1 and Amb t 5 were increased at Seoul than those at Pocheon.
Conclusion Increased CO2 significantly influence allergenicity and pollen concentration of common ragweed through the chamber and field study. The elementary example given here demonstrates strong probable links between rising CO2 levels and increased allergic diseases. We suggest that urbanization might provide a alternative to current experimental methods evaluating plant responses to climate change.