Rubisco concentration and total leaf carboxylase activity was reduced but leaf and canopy photosynthesis remained high in Scirpus olneyi grown in the field at elevated atmospheric CO[sub 2] for seven years

Conference · Wed Jun 01 04:00:00 EDT 1994 · Bulletin of the Ecological Society of America; (United States)

OSTI ID:7272372

Jacob, J; Drake, B G ^[1]

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1. Smithsonian Environmental Research Center, Edgewater, MD (United States)

Photosynthetic gas exchange by leaves (A) at different leaf internal CO[sub 2] concentrations (C[sub 1]) were measured and related to leaf biochemical composition and canopy photosynthesis in Scirpus olneyi grown in open top chambers in the field at ambient and elevated (ambient + 340 ppm) CO[sub 2]. Plants from elevated CO[sub 2] had significantly higher (52%) A than plants from ambient CO[sub 2] when measured in their respective growth CO[sub 2] concentrations. Elevated CO[sub 2] decreased leaf soluble protein (40-52%) and Rubisco (30-55%) contents, increased soluble sugar (52%) and starch (44%). Rubisco activation state increased slightly, but then in situ leaf carboxylase activity decreased substantially in elevated CO[sub 2] grown leaves and this caused lower initial slope of the response of A to C. The CO[sub 2] saturated photosynthetic rate was higher in leaves from elevated CO[sub 2] than leaves from ambient CO[sub 2]. A model of canopy photosynthesis using measured parameters of leaf photosynthesis showed that total CO[sub 2] assimilated per m[sup 2] land area per day increased markedly in the elevated CO[sub 2] treatment.

• OSTI ID: 7272372
• Report Number(s): CONF-940894--
• Conference Information: Journal Name: Bulletin of the Ecological Society of America; (United States) Journal Volume: 75:2
• Country of Publication: United States
• Language: English

Related Subjects

560300* -- Chemicals Metabolism & Toxicology
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
BIOCHEMISTRY
BIOLOGICAL EFFECTS
CARBON COMPOUNDS
CARBON DIOXIDE
CARBON OXIDES
CHALCOGENIDES
CHEMICAL REACTIONS
CHEMISTRY
ECOLOGICAL CONCENTRATION
MATHEMATICAL MODELS
OXIDES
OXYGEN COMPOUNDS
PHOTOCHEMICAL REACTIONS
PHOTOSYNTHESIS
PLANTS
SYNTHESIS