Minor physiological response to elevated CO/sub 2/ by the CAM plant Agave vilmoriniana

Journal Article · Wed Apr 01 04:00:00 EST 1987 · Plant Physiol.; (United States)

OSTI ID:6021162

Szarek, S R; Holthe, P A; Ting, I P

One-year-old plants of the CAM leaf succulent Agave vilmoriniana Berger were grown outdoors at Riverside, California. Potted plants were acclimated to CO/sub 2/-enrichment (about 750 microliters per liter) by growth for 2 weeks in an open-top polyethylene chamber. Control plants were grown nearby where the ambient CO/sub 2/ concentration was about 370 microliters per liter. When the plants were well watered, CO/sub 2/-induced differences in stomatal conductances and CO/sub 2/ assimilation rates over the entire 24-hour period were not large. There was a large nocturnal acidification in both CO/sub 2/ treatments and insignificant differences in leaf chlorophyll content. Well watered plants maintained water potentials of -0.3 to -0.4 megapascals. When other plants were allowed to dry to water potentials of -1.2 to -1.7 megapascals, stomatal conductances and CO/sub 2/ uptake rates were reduced in magnitude, with the biggest difference in Phase IV photosynthesis. The minor nocturnal response to CO/sub 2/ by this species is interpreted to indicate saturated, or nearly saturated, phosphoenolpyruvate carboxylase activity at current atmospheric CO/sub 2/ concentrations. CO/sub 2/-enhanced diurnal activity of ribulose bisphosphate carboxylase activity remains a possibility.

• Research Organization: Univ. of California, Riverside
• OSTI ID: 6021162
• Journal Information: Plant Physiol.; (United States), Journal Name: Plant Physiol.; (United States) Vol. 83:4; ISSN PLPHA
• Country of Publication: United States
• Language: English

Related Subjects

551000* -- Physiological Systems
59 BASIC BIOLOGICAL SCIENCES
BIOLOGICAL EFFECTS
CARBON COMPOUNDS
CARBON DIOXIDE
CARBON OXIDES
CARBON-CARBON LYASES
CARBOXY-LYASES
CARBOXYLASE
CHALCOGENIDES
CHEMICAL REACTIONS
ENRICHMENT
ENZYME ACTIVITY
ENZYMES
GROWTH
HYDROGEN COMPOUNDS
LYASES
OPENINGS
OXIDES
OXYGEN COMPOUNDS
PHOTOCHEMICAL REACTIONS
PHOTOSYNTHESIS
PHYSIOLOGY
PLANT GROWTH
PLANTS
STOMATA
SYNTHESIS
WATER