Concentration and metabolic turnover of UDP-glucose in developing cotton fibers

Journal Article · Sat Jan 10 04:00:00 EST 1981 · J. Biol. Chem.; (United States)

OSTI ID:6601244

Carpita, N C ^[1]; Delmer, D P

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1. Purdue Univ., West Lafayette, IN

The flow of carbon in vivo from glucose to cellulose in developing cotton fibers which were actively engaged in the deposition of a cellulosic secondary cell wall was traced. Steady state levels of nucleotide sugars were analyzed from developing cotton fibers harvested between 13 and 36 days post-anthesis (DPA). The UDP-sugars were the predominant nucleotide sugars. UDP-glucose constituted over 75% of the UDP-sugar fraction, but UDP-galactose and traces of other UDP-sugars were also detected. The UDP-glucose levels increased from 0.2 ..mu..mol/boll at 13 DPA to over 2.1 ..mu..mol/boll by 24 DPA, just prior to the maximum rate of secondary wall cellulose synthesis; the levels dropped precipitously at the time when cellulose synthesis ceased. Fibers, cultured in vitro possess a very similar nucleotide-sugar composition to that of plant-grown fibers. When such fibers are pulse-labeled in vivo with (/sup 14/C)glucose, UDP-glucose is the predominant nucleotide sugar labeled. Pool size and rates of labeling of glucose, glucose-phosphate, and UDP-glucose pool data were analyzed using a computer simulation model, and it was determined that the rate of synthesis and turnover of UDP-glucose is more than sufficient to account for the combined rates of accumulation of sucrose, sterylglucosides, ..beta..-1,3-glucan, and cellulose. These data strongly indicate that UDP-glucose is a precursor to secondary wall cellulose in the cotton fiber.

• OSTI ID: 6601244
• Journal Information: J. Biol. Chem.; (United States), Journal Name: J. Biol. Chem.; (United States) Vol. 256:1; ISSN JBCHA
• Country of Publication: United States
• Language: English

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59 BASIC BIOLOGICAL SCIENCES
60 APPLIED LIFE SCIENCES
BIOSYNTHESIS
CARBOHYDRATES
CARBON 14 COMPOUNDS
CELL CONSTITUENTS
CELL WALL
CELLULOSE
CORRELATIONS
COTTON PLANTS
FIBERS
GLYCOSIDES
ISOTOPE APPLICATIONS
LABELLED COMPOUNDS
METABOLISM
NUCLEOTIDES
ORGANIC COMPOUNDS
ORGANIC PHOSPHORUS COMPOUNDS
PLANT CELLS
PLANTS
POLYSACCHARIDES
PRECURSOR
SACCHARIDES
SYNTHESIS
TRACER TECHNIQUES
UDPG