Carbon assimilation and export in sugar beet leaves. [Beta vulgaris]
Net carbon exchange rates (NCE), starch accumulation rates, gas exchange, and the maximum amount of carbon available for export were studied in Beta vulgaris L. following a 25% increase or a 25% decrease in ambient CO/sub 2/ (340 ..mu..l/L). Changing CO/sub 2/ by 25% above or below ambient had no effect on the ratio of internal CO/sub 2/ to ambient CO/sub 2/. Stomatal aperature adjusted in both cases to maintain the same relative stomatal limitation to NCE. Increasing CO/sub 2/ 25% increased NCE and water use efficiency, but slightly decreased stomatal conductance by 9% below leaves maintained at ambient. In contrast, a 25% reduction in CO/sub 2/ decreased NCE and water use efficiency. Decreasing CO/sub 2/ caused an increase in conductance also by 9%. Increasing CO/sub 2/ increased starch storage by 36%, but caused no change in the ratio of starch accumulation to NCE. A reduction in CO/sub 2/ caused a 60% decrease in the rate of starch storage and decreased the ratio of starch accumulation to NCE by one-half. The maximum amount of carbon available for export was increased 25% by increasing CO/sub 2/, but decreased by 5% following a reduction in CO2 level. These data are evidence that export rates are maintained at the expense of starch synthesis during periods of low NCE.
- Research Organization:
- Univ. of Dayton, OH
- OSTI ID:
- 6065286
- 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
Similar Records
Effects of water stress on photosynthesis and carbon partitioning in soybean (Glycine max (L. ) Merr. ) plants grown in the field at different CO/sub 2/ levels
Effect of altered sink:source ratio on photosynthetic metabolism of source leaves
Related Subjects
59 BASIC BIOLOGICAL SCIENCES
CARBOHYDRATES
TRANSLOCATION
CARBON DIOXIDE
BIOLOGICAL EFFECTS
STOMATA
BIOLOGICAL FUNCTIONS
BIOSYNTHESIS
METABOLISM
PHOTOSYNTHESIS
STARCH
SUGAR BEETS
BEETS
CARBON COMPOUNDS
CARBON OXIDES
CHALCOGENIDES
CHEMICAL REACTIONS
FOOD
FUNCTIONS
OPENINGS
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PHOTOCHEMICAL REACTIONS
PLANTS
POLYSACCHARIDES
REAGENTS
SACCHARIDES
SYNTHESIS
VEGETABLES
560300* - Chemicals Metabolism & Toxicology
550200 - Biochemistry
551000 - Physiological Systems