Turgor-regulated sugar release in sugarbeet leaves

Journal Article · Sat Apr 01 04:00:00 EST 1989 · Plant Physiology, Supplement; (USA)

OSTI ID:6945322

Daie, J ^[1]

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1. 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), Journal Name: Plant Physiology, Supplement; (USA) Vol. 89:4; ISSN PPYSA; ISSN 0079-2241
• Country of Publication: United States
• Language: English

Related Subjects

09 BIOMASS FUELS
090800 -- Biomass Fuels-- Production-- (1990-)
553002* -- Agriculture & Food Technology-- Horticulture-- (1987-)
60 APPLIED LIFE SCIENCES
BEETS
BIOCHEMICAL REACTION KINETICS
CARBOHYDRATES
CARBON 14 COMPOUNDS
CARBON COMPOUNDS
CARBON DIOXIDE
CARBON OXIDES
CHALCOGENIDES
DISACCHARIDES
DROUGHTS
FOOD
ISOTOPE APPLICATIONS
KINETICS
LABELLED COMPOUNDS
LEAVES
MAGNOLIOPHYTA
MAGNOLIOPSIDA
OLIGOSACCHARIDES
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PHYSIOLOGY
PLANTS
REACTION KINETICS
SACCHARIDES
SACCHAROSE
SUGAR BEETS
TRACER TECHNIQUES
VEGETABLES