Effects of CO/sub 2/ concentration on rubisco amount, activity, and photosynthesis in soybean leaves
Soybeans were grown at CO/sub 2/ concentrations ranging from 160 to 990 ..mu..l L/sup -1/ in outdoor chambers receiving natural sunlight. Leaf soluble protein and total rubisco activity decreased with increasing growth CO/sub 2/, when expressed on a dry weight basis, but no decrease occurred on an area basis. On an area basis, leaf photosynthetic rates of plants grown at 330 and 660 ..mu..l CO/sub 2/ L/sup -1/, and measured over a range of intercellular CO/sub 2/ of 50 to 680 ..mu..l CO/sub 2/ L/sup -1/, were always greater in the high CO/sub 2/ grown plants. Rubisco content (percent of soluble protein) and total activity (soluble protein basis), remained unchanged over the range of growth CO/sub 2/. Since rubisco content and total activity per m/sup 2/ were independent of growth CO/sub 2/ concentration, the enhanced rate of photosynthesis of leaves grown at high CO/sub 2/ was apparently not due to an increase in rubisco amount or activity. Soybean grown at high CO/sub 2/ has an extra palisade cell layer per unit leaf area. Thus, the greater photosynthetic rates of high CO/sub 2/ grown leaves may result from an enhanced ability of CO/sub 2/ to gain access to rubisco via increased total mesophyll cell surface area.
- Research Organization:
- Univ. of Florida, Gainesville
- DOE Contract Number:
- AI01-81ER60001
- OSTI ID:
- 6031150
- Report Number(s):
- CONF-8707108-
- Journal Information:
- Plant Physiol., Suppl.; (United States), Vol. 83:4; Conference: Annual meeting of the American Society of Plant Physiologists, St. Louis, MO, USA, 19 Jul 1987
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
CARBON DIOXIDE
BIOLOGICAL EFFECTS
RIBULOSE DIPHOSPHATE CARBOXYLASE
ENZYME ACTIVITY
EXPOSURE CHAMBERS
GLYCINE HISPIDA
LEAVES
PHOTOSYNTHESIS
PROTEINS
BACTERIA
CARBON COMPOUNDS
CARBON OXIDES
CARBON-CARBON LYASES
CARBOXY-LYASES
CHALCOGENIDES
CHEMICAL REACTIONS
ENZYMES
LEGUMINOSAE
LYASES
MICROORGANISMS
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PHOTOCHEMICAL REACTIONS
PLANTS
RHIZOBIUM
SYNTHESIS
550200* - Biochemistry
560300 - Chemicals Metabolism & Toxicology