( sup 14 C)-Sucrose uptake by guard cell protoplasts of pisum sativum, argenteum mutant

Conference · Wed May 01 00:00:00 EDT 1991 · Plant Physiology, Supplement; (United States)

OSTI ID:5561033

Rohrig, K; Raschke, K ^[1]

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1. Univ. Goettingen (West Germany)

Guard cells rely on import for their supply with reduced carbon. The authors tested by silicone oil centrifugation the ability of guard cell protoplasts to accumulated ({sup 14}C)-sucrose. Uptake rates were corrected after measurement of {sup 14}C-sorbitol and {sup 3}H{sub 2}O spaces. Sucrose uptake followed biphasic kinetics, with a high-affinity component below 1 mM external sucrose (apparent K{sub m} 0.8 mM at 25C) and a low-affinity nonsaturable component above. Uptake depended on pH (optimum at pH 5.0). Variations in the concentrations of external KCl, CCCP, and valinomycin indicated that about one-half of the sucrose uptake rate could be related to an electrochemical gradient across the plasmalemma. Total uptake rates measured at 5 mM external sucrose seem to be sufficient to replenish emptied plastids with starch within a few hours.

• OSTI ID: 5561033
• Report Number(s): CONF-9107184-; CODEN: PPYSA
• Journal Information: Plant Physiology, Supplement; (United States), Vol. 96:1; Conference: Annual meeting of the American Society of Plant Physiology, Albuquerque, NM (United States), 28 Jul - 1 Aug 1991; ISSN 0079-2241
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
PISUM
PHYSIOLOGY
SACCHARIDES
UPTAKE
CARBON 14 COMPOUNDS
CELL CONSTITUENTS
MUTANTS
TRACER TECHNIQUES
TRITIUM COMPOUNDS
CARBOHYDRATES
CARBON COMPOUNDS
HYDROGEN COMPOUNDS
ISOTOPE APPLICATIONS
LABELLED COMPOUNDS
LEGUMINOSAE
MAGNOLIOPHYTA
MAGNOLIOPSIDA
ORGANIC COMPOUNDS
PLANTS
551001* - Physiological Systems- Tracer Techniques