Combined effects of chronic ozone and elevated CO2 on Rubisco activity and leaf components in soybean (Glycine max)

Abstract

per unit Rubisco content of plants in grown CF-AA, and increased LMA by 27-74% of the leaf mass Content and activity of Rubisco and concentrations of per unit area in CF-AA because of a 23-148% increase leaf nitrogen, chlorophyll and total non-structural car- in starch. However, the data suggest that, at elevated bohydrates (TNC) were determined at regular intervals (CO 2 ), increases in starch and sucrose are not directly during the 1993 and 1994 growing seasons to under- responsible for the deactivation of Rubisco. Also, there stand the effects and interactions of (O 3 ) and elevated was little evidence of an adjustment of Rubisco activity (CO 2 ) on biochemical limitations to photosynthesis in response to starch and sucrose metabolism. during ontogeny. Soybean (Glycine max var. Essex) was Significant interactions between elevated (CO 2 ) and grown in open-top field chambers in either charcoal- (O