Turgor-regulated sugar release in sugarbeet leaves
- Rutgers Univ., New Brunswick, NJ (USA)
Under drought conditions, sucrose distribution (osmotic adjustment vs. export) may be regulated at the mesophyll plasmalemma/tonoplast. Leaves were given {sup 14}CO{sub 2} for a 30/30 min pulse/chase. Peeled leaf discs were put in low or high osmotic solutions to monitor release of labeled solutes. High turgor increased efflux rates double those at low turgor. About 30% and 55% of the released label was in the sugar (sucrose + hexose) fractions at low and high turgor, respectively. Response to changes in cell turgor was rapid and reversible. PCMBS had no effect on efflux. NEM and CCCP enhanced efflux at high turgor. Presence of unlabeled sucrose in the wash solutions greatly enhanced sucrose efflux in a turgor-dependent manner; suggesting the presence of a sucrose exchange system, which appeared to be at the tonoplast. Turgor-regulated efflux involved both the tonoplast and plasmalemma. However, efflux across the plasmalemma was not carrier-mediated.
- OSTI ID:
- 6945322
- Journal Information:
- Plant Physiology, Supplement; (USA), Vol. 89:4; ISSN 0079-2241
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
09 BIOMASS FUELS
SACCHAROSE
BIOCHEMICAL REACTION KINETICS
SUGAR BEETS
PHYSIOLOGY
BEETS
CARBON 14 COMPOUNDS
CARBON DIOXIDE
DROUGHTS
LEAVES
TRACER TECHNIQUES
CARBOHYDRATES
CARBON COMPOUNDS
CARBON OXIDES
CHALCOGENIDES
DISACCHARIDES
FOOD
ISOTOPE APPLICATIONS
KINETICS
LABELLED COMPOUNDS
MAGNOLIOPHYTA
MAGNOLIOPSIDA
OLIGOSACCHARIDES
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PLANTS
REACTION KINETICS
SACCHARIDES
VEGETABLES
553002* - Agriculture & Food Technology- Horticulture- (1987-)
090800 - Biomass Fuels- Production- (1990-)