Assimilate utilization in the leaf canopy and whole-plant growth of soybean during acclimation to elevated CO/sub 2/

Journal Article · Sun Mar 01 04:00:00 EST 1987 · Bot. Gaz. (Chicago); (United States)

OSTI ID:6351047

Cure, J D; Rufty, Jr, T W; Israel, D W

Young vegetative soybeans (Glycine max Ransom) were exposed to control (350 /sup +/L L/sup -1/ CO/sub 2/) or CO/sub 2-/ enriched (700 ..mu..L L/sup -1/ CO/sub 2/) environments continuously for 22 days. Alterations in carbon acquisition, assimilate utilization by the leaf canopy, and whole plant-growth were followed to characterize plant acclimation at high CO/sub 2/. Whole-plant dry weight (DW) progressively increased at high CO/sub 2/ relative to the control throughout the experiment. The initial DW increases were associated with the accumulation of nonstructural assimilates in leaves and increased specific leaf weight (SLW). After 3 days, however, DW began to accumulate rapidly in stems and roots under high CO/sub 2/, and SLW no longer increased relative to controls. Total leaf area did not increase significantly at high CO/sub 2/ until 13 days after the start of treatment. Net assimilation rates declined under both CO/sub 2/ conditions but remained higher at 700 ..mu..L L/sup -1/ CO/sub 2/ throughout the experiment. The increases in stem and root DW during week 1 at high CO/sub 2/ were accompanied by an early increase in the stimulated rate of assimilate utilization in the canopy during the dark phase of the diurnal cycle and a later increase in the estimated rate of assimilate utilization during the light phase. The results indicate that dark mobilization of assimilates from source leaves responded to variations in assimilate accumulation but that export of assimilates from source leaves in the light adjusted more slowly and appeared to be coordinated with large changes in sink activity in the whole plant.

• Research Organization: Duke Univ., NC
• DOE Contract Number: FG05-85ER60373
• OSTI ID: 6351047
• Journal Information: Bot. Gaz. (Chicago); (United States), Journal Name: Bot. Gaz. (Chicago); (United States) Vol. 148:1; ISSN BOGAA
• 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.
BACTERIA
BIOLOGICAL ADAPTATION
BIOLOGICAL EFFECTS
CANOPIES
CARBON COMPOUNDS
CARBON DIOXIDE
CARBON OXIDES
CHALCOGENIDES
DAILY VARIATIONS
ELECTROMAGNETIC RADIATION
GLYCINE HISPIDA
GROWTH
LEAVES
LEGUMINOSAE
MICROORGANISMS
OXIDES
OXYGEN COMPOUNDS
PLANT GROWTH
PLANTS
RADIATIONS
RHIZOBIUM
SINKS
VARIATIONS
VISIBLE RADIATION