Photosynthesis and carbohydrate partitioning for the C{sub 3} desert shrub encelia farinosa under current and doubled CO{sub 2} concentrations

Journal Article · Mon Apr 01 04:00:00 EST 1996 · Plant Physiology (Bethesda)

OSTI ID:379418

Zhang, Hehui; Nobel, P S ^[1]

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1. Univ. of California, Los Angeles, CA (United States)

Changes in photosynthesis (A) and carbohydrate partitioning were studied for Encelia farinosa, a common C{sub 3} desert shrub in the southwestern United States, after a 3-month exposure to the current or a doubled CO{sub 2} concentration (750 {mu}L L{sup -1}). A remained unchanged under the current CO{sub 2} concentration but decreased during the day under the doubled CO{sub 2} concentration, resulting in a 46% enhancement in the early morning 26% at midday, and 15% in the late afternoon by the elevated CO{sub 2}. The decrease during the day under the doubled CO{sub 2} concentration may represent end-product inhibition, because the sucrose and the starch contents increased during the day proportionally more than under the current CO{sub 2} concentration. The {sup 14}CO{sub 2} activity in sink leaves was maximal 3 h after labeling under the doubled and at 5 h under the current CO{sub 2} concentration, indicating faster movement of photosynthate out of source leaves and into sink tissues under the doubled CO{sub 2} concentration, which may have been responsible for the sustained enhancement in A under the doubled CO{sub 2} concentration. 32 refs., 5 figs.

• DOE Contract Number: FG03-93ER61686
• OSTI ID: 379418
• Journal Information: Plant Physiology (Bethesda), Journal Name: Plant Physiology (Bethesda) Journal Issue: 4 Vol. 110; ISSN 0032-0889; ISSN PLPHAY
• Country of Publication: United States
• Language: English

Related Subjects

56 BIOLOGY AND MEDICINE
APPLIED STUDIES
BIOLOGICAL EFFECTS
CARBOHYDRATES
CARBON DIOXIDE
PHOTOSYNTHESIS
SHRUBS