Aspen Bibliography


Genetic control of responses to interacting tropospheric ozone and CO2 in Populus tremuloides

Document Type

Contribution to Book


Selected papers from the 17th International meeting for specialists in air pollution effects on forest ecosystems

Publication Date



We exposed trembling aspen (Populus tremuK&s Michx.) clones differing in tropospheric ozone (O$ tolerance in various open-

top chamber studies for rhree growing seasons, and examined the effects of 03, COz, and O3 + CO2 on growth and physiological

processes. Ozone in the range of 80 ppm hr (Sum 00) per growing season decreased height, diameter, and stem and leaf biomass slightly in a tolerant clone but severely in a sensitive clone. Elevated CO2 (150 ppm over ambient) did not compensate for the O3

effects. Antioxidant enzyme analysis showed elevated SOD levels in the tolerant clone but not in the sensitive clone following O3 exposure.

Northern blot analysis indicated that the chloroplastic and cytosolic CwZn SOD’s were significantly increased in response to O3 in

the tolerant but not the sensitive clone. Currently, we are conducting molecular analysis to determine the functional significance of SOD’s in regulaling O3 tolerance in aspen.