Phloem unloading in tomato fruit

Conference · Tue Apr 01 04:00:00 EST 1986 · Plant Physiol., Suppl.; (United States)

OSTI ID:5121578

Damon, S; Hewitt, J; Bennett, A B

To begin to identify those processes that contribute to the regulation of photosynthate partitioning in tomato fruit the path of phloem unloading in this tissue has been characterized. Assymetrically labelled sucrose (/sup 3/H-fructosyl sucrose) was applied to source leaves. Following translocation to the fruit the apoplast was sampled. The appearance of assymetric sucrose and /sup 3/H-fructose in the apoplast indicates that phloem unloading is apoplastic and that extracellular invertase is active. Estimation of sucrose, glucose, and fructose concentrations in the apoplast were 1 mM, 40 mM, and 40 mM, respectively. Rates of uptake of sucrose, 1-fluorosucrose, glucose, and fructose across the plasma membrane were similar and non-saturating at physiological concentrations. These results suggest that, although extracellular invertase is present, sucrose hydrolysis is not required for uptake into tomato fruit pericarp cells. 1-fluorosucrose is used to investigate the role of sucrose synthase in hydrolysis of imported photosynthate.

• Research Organization: Univ. of California, Davis
• OSTI ID: 5121578
• Conference Information: Journal Name: Plant Physiol., Suppl.; (United States) Journal Volume: 80:4
• Country of Publication: United States
• Language: English

Related Subjects

551001* -- Physiological Systems-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BIOLOGICAL PATHWAYS
CARBOHYDRATES
CELL CONSTITUENTS
CELL WALL
DISACCHARIDES
FOOD
FRUITS
HYDROGEN ISOTOPES
ISOTOPES
LABELLING
LEAVES
LIGHT NUCLEI
NUCLEI
ODD-EVEN NUCLEI
OLIGOSACCHARIDES
ORGANIC COMPOUNDS
RADIOISOTOPES
RADIONUCLIDE KINETICS
SACCHARIDES
SACCHAROSE
TOMATOES
TRANSLOCATION
TRITIUM
UPTAKE
YEARS LIVING RADIOISOTOPES