A kinetic and microautoradiographic study of sup 14 C-sucrose translocation into developing wheat grains

Conference · Wed May 01 04:00:00 EDT 1991 · Plant Physiology, Supplement; (United States)

OSTI ID:5640341

Wang, Ning; Fisher, D B ^[1]

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1. Washington State Univ., Pullman (United States)

The kinetics of {sup 14}C-photosynthate import by developing wheat grains was followed after pulse-labeling the flag leaf with {sup 14}CO{sub 2}. Samples were collected from four successive points along the transport pathway to and within the grain: exuding aphid stylets on the peduncle, exuding grain pedicels, the grain crease tissues, and the liquid contents of the endosperm cavity. In addition, microautoradiographs were prepared of the grain crease tissues during movement of the {sup 14}C pulse into the grain. At all times, sucrose accounted for 93 to 97% of the total {sup 14}C present at all four sampling sites. The main features of the {sup 14}C kinetics could be accounted for by a simple compartmental model consisting of sucrose pools in series. Microautoradiographs of the crease tissues showed fairly uniform labeling of vascular parenchyma at all times, with a sharp gradient in labeling across the chalaza to the nucellus. Thus the principal resistance to post-phloem solute transport through the maternal tissues appears to be in the symplastic pathway across the chalaza.

• OSTI ID: 5640341
• Report Number(s): CONF-9107184--
• Conference Information: Journal Name: Plant Physiology, Supplement; (United States) Journal Volume: 96:1
• Country of Publication: United States
• Language: English

Related Subjects

550501* -- Metabolism-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
AUTORADIOGRAPHY
BIOLOGICAL PATHWAYS
CARBOHYDRATES
CARBON 14 COMPOUNDS
CARBON COMPOUNDS
CARBON DIOXIDE
CARBON OXIDES
CEREALS
CHALCOGENIDES
CHEMICAL REACTIONS
DISACCHARIDES
GRAMINEAE
LABELLED COMPOUNDS
LEAVES
LILIOPSIDA
MAGNOLIOPHYTA
METABOLISM
OLIGOSACCHARIDES
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PHOTOCHEMICAL REACTIONS
PHOTOSYNTHESIS
PHYSIOLOGY
PLANTS
SACCHARIDES
SACCHAROSE
SYNTHESIS
TRANSLOCATION
WHEAT