Effects of CO sub 2 concentration on rubisco activity, amount, and photosynthesis in soybean leaves

Journal Article · Thu Dec 01 00:00:00 EST 1988 · Plant Physiology; (USA)

DOI:https://doi.org/10.1104/pp.88.4.1310· OSTI ID:6905712

Campbell, W J; Allen, Jr, L H; Bowes, G ^[1]

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1. Univ. of Florida, Gainesville (USA)

Growth at an elevated CO{sub 2} concentration resulted in an enhanced capacity for soybean (Glycine max L. Merr. cv Bragg) leaflet photosynthesis. Plants were grown from seed in outdoor controlled-environment chambers under natural solar irradiance. Photosynthetic rates, measured during the seed filling stage, were up to 150% greater with leaflets grown at 660 compared to 330 microliters of CO{sub 2} per liter when measured across a range of intercellular CO{sub 2} concentrations and irradiance. Soybean plants grown at elevated CO{sub 2} concentrations had heavier pod weights per plant, 44% heavier with 660 compared to 330 microliters of CO{sub 2} per liter grown plants, and also greater specific leaf weights. Ribulose 1,5-bisphosphate carboxylase/oxygenase (rubisco) activity showed no response (mean activity of 96 micromoles of CO{sub 2} per square meter per second expressed on a leaflet area basis) to short-term ({approximately}1 hour) exposures to a range of CO{sub 2} concentrations (110-880 microliters per liter), nor was a response of activity (mean activity of 1.01 micromoles of CO{sub 2} per minute per milligram of protein) to growth CO{sub 2} concentration (160-990 microliters per liter) observed. The amount of rubisco protein was constant, as growth CO{sub 2} concentration was varied, and averaged 55% of the total leaflet soluble protein. Although CO{sub 2} is required for activation of rubisco, results indicated that within the range of CO{sub 2} concentrations used (110-990 microliters per liter), rubisco activity in soybean leaflets, in the light, was not regulated by CO{sub 2}.

• DOE Contract Number: AI01-81ER60001
• OSTI ID: 6905712
• Journal Information: Plant Physiology; (USA), Vol. 88:4; ISSN 0032-0889
• Country of Publication: United States
• Language: English

Related Subjects

63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
CARBON DIOXIDE
BIOLOGICAL EFFECTS
CARBOXY-LYASES
BIOCHEMICAL REACTION KINETICS
GLYCINE HISPIDA
PHOTOSYNTHESIS
ENZYME ACTIVITY
LEAVES
PLANT GROWTH
CARBON COMPOUNDS
CARBON OXIDES
CARBON-CARBON LYASES
CHALCOGENIDES
CHEMICAL REACTIONS
ENZYMES
GROWTH
KINETICS
LEGUMINOSAE
LYASES
MAGNOLIOPHYTA
MAGNOLIOPSIDA
OXIDES
OXYGEN COMPOUNDS
PHOTOCHEMICAL REACTIONS
PLANTS
REACTION KINETICS
SYNTHESIS
560300* - Chemicals Metabolism & Toxicology