Acclimation of Photosynthesis to Elevated CO₂ in Five C₃ Species

Abstract

The effect of long-term (weeks to months) CO2 enhancement on (a) the gas-exchange characteristics, (b) the content and activation state of ribulose-1,5-bisphosphate carboxylase (rubisco), and (c) leaf nitrogen, chlorophyll, and dry weight per area were studied in five C3 species (Chenopodium album, Phaseolus vulgaris, Solanum tuberosum, Solanum melongena, and Brassica oleracea) grown at CO2 partial pressures of 300 or 900 to 1000 microbars. Long-term exposure to elevated CO2 affected the CO2 response of photosynthesis in one of three ways: (a) the initial slope of the CO2 response was unaffected, but the photosynthetic rate at high CO2 increased (S. tuberosum); (b) the initial slope decreased but the C02-saturated rate of photosynthesis was little affected (C. album, P. vulgaris); (c) both the initial slope and the C02-saturated rate of photosynthesis decreased (B. oleracea, S. melongena). In all five species, growth at high CO2 increased the extent to which photosynthesis was stimulated following a decrease in the partial pressure of 02 or an increase in measurement CO2 above 600 microbars. This stimulation indicates that a limitation on photosynthesis by the capacity to regenerate orthophosphate was reduced or absent after acclimation to high CO2. Leaf nitrogen per area either increased (S. tuberosum, S. melongena) or was little changed by CO2 enhancement. The content of rubisco was lower in only two of the five species, yet its activation state was 19% to 48% lower in all five species following longterm exposure to high CO2. These results indicate that during growth in C02-enriched air, leaf rubisco content remains in excess of that required to support the observed photosynthetic rates.During short-term (minutes to hours) exposure to elevated partial pressure of C02, the rate of light-saturated CO2 assimilation (A2) in many C3 plants is primarily limited by the capacity to regenerate Pi from phosphorylated photosynthetic intermediates (10, 17,22,23,26). A Pi-regeneration limitation of photosynthesis is characterized by a lack of sensitivity ofA to changes in ambient partial pressure of CO2 and/ or 02 (10,

CO2-response function of radiation use efficiency in rice for climate change scenarios

“…The saturation of RUE response to CO 2 concentrations approaching 1000 ppmv (Figure 1) is consistent with the saturation of leaf photosynthesis in C 3 plants at 800-1000 ppmv (Sage et al, 1989;Streck, 2005). At low and intermediate atmospheric CO 2 concentrations, photosynthesis is limited by the carboxylation capacity of Rubisco, while at high CO 2 concentrations leaf photosynthesis is limited by the regeneration capacity of Rubisco in the Calvin cycle (Chen et al, 2005).…”

“…The sigmoidal response of RUE to an increase in atmospheric CO 2 concentration, obtained in the present study (equation 2, Figure 1), differed from the overall response of leaf photosynthesis to CO 2 commonly reported in C 3 plants, which follows a rectangular hyperbole-type shape response (Sage et al, 1989;Streck, 2005). The main difference between the sigmoidal response and rectangular hyperbole response to CO 2 was from about 350 to 700 ppmv.…”

Acquisition and allocation of carbon and nitrogen by Danthonia richardsonii in response to restricted nitrogen supply and CO2 enrichment

“…Total soluble protein and Rubisco contents (g m -2 ) have been observed to decline in response to CO 2 enrichment in D. richardsonii (Lutze & Gifford, unpublished). Rubisco (Sage, Sharkey & Seemann 1989;Besford 1990;RowlandBamford et al 1991) and chlorophyll contents (g m -2 ; Sage et al 1989;Xu, Gifford & Chow 1994) have often decreased in a range of plant species in response to CO 2 enrichment.…”

The relationship between CO2 assimilation, photosynthetic electron transport and water–water cycle in chill‐exposed cucumber leaves under low light and subsequent recovery

“…Inorganic phosphate limitation is characterized by reduced sensitivity to O 2 at low temperatures (Leegood & Furbank 1986;Sage & Sharkey 1987;Sage, Sharkey & Sharkey 1989).…”