Incorporation of UDPglucose into cell wall glucans and lipids by intact cotton fibers
The (/sup 14/C) moiety from (/sup 3/H)UDP(/sup 14/C)glucose was incorporated by intact cotton fibers into hot water soluble, acetic-nitric reagent soluble and insoluble components, and chloroform-methanol soluble lipids; the (/sup 3/H)UDP moiety was not incorporated. The /sup 3/H-label can be exchanged rapidly with unlabeled substrate in a chase experiment. The cell wall apparent free space of cotton fibers was in the order of 30 picomoles per milligram of dry fibers; 25 picomoles per milligram easily exchanged and about 5 picomoles per milligram more tightly adsorbed. At 50 micromolar UDPglucose, 70% of the (/sup 14/C)glucose was found in the lipid fraction after both a short labeling period and chase. The percent of (/sup 14/C)glucose incorporated into total glucan increased within a 30-minute chase period. The data supports the concept that glucan synthesis, including cellulose, as well as the synthesis of steryl glucosides, acetylated steryl glucosides, and glucosyl-phosphoryl-polyprenol from externally supplied UDPglucose occurs at the plasma membrane-cell wall interface. The synthase enzymes for such synthesis must be part of this interfacial membrane system.
- Research Organization:
- Univ. of California, Riverside
- OSTI ID:
- 7188090
- Journal Information:
- Plant Physiol.; (United States), Journal Name: Plant Physiol.; (United States) Vol. 81:2; ISSN PLPHA
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
59 BASIC BIOLOGICAL SCIENCES
ALDEHYDES
BIOCHEMICAL REACTION KINETICS
BIOSYNTHESIS
CARBOHYDRATES
CARBON 14 COMPOUNDS
CELL CONSTITUENTS
CELL MEMBRANES
COTTON
COTTON PLANTS
ENZYME ACTIVITY
FIBERS
GLUCOSE
HEXOSES
ISOTOPE APPLICATIONS
KINETICS
LABELLED COMPOUNDS
LIPIDS
MEMBRANES
MONOSACCHARIDES
ORGANIC COMPOUNDS
PHYSIOLOGY
PLANTS
POLYSACCHARIDES
REACTION KINETICS
SACCHARIDES
SYNTHESIS
TRACER TECHNIQUES
TRITIUM COMPOUNDS