[U-14C]-D-Glucose (1 and 20 mm) was added to glucose-grown suspension cultures of Puccinia graminis, and the sequence of movement of the label into metabolic intermediates was determined under steady-state conditions. Radioactive label moved most rapidly into cellular pools of free glucose, amino acids and phosphate esters of trehalose and glucose, and less rapidly into free fructose. No lag was detected in the movement of label into any of these compounds. Thus fructose was the first free carbohydrate synthesized from glucose. Radioactive label moved more slowly, and with an initial lag phase, into trehalose, glucitol and mannitol; the lag was more pronounced for mannitol than glucitol. Kinetic data and specific activity measurements to identify precursors suggest that trehalose was formed via trehalose phosphate, mannitol via fructose, and glucitol via both glucose and fructose. Steady-state specific activities of all free intracellular carbohydrates were much lower (15-50%) than that of the exogenous glucose, indicating that unlabelled carbon was entering these pools from storage reserves or other components from the culture medium.
HueL.1981; The role of futile cycles in the regulation of carbohydrate metabolism in the liver. Advances in Enzymology and Related Areas of Molecular Biology 52:247–331
LewisD. H.1976; Interchange of metabolites in biotrophic symbioses between angiosperms and fungi. In Perspectives in Experimental Biology2 Botany p. 207SunderlandN.
Edited by Oxford: Pergamon Press;
MacleanD. J.1974; Cultural and nutritional studies on variant strains of the wheat stem rust fungus. Transactions of the British Mycological Society 62:333–349
MacleanD. J.1982; Axenic culture and metabolism of rust fungi. In The Rust Fungi pp. 37–120ScottK. J.,
ChakravortyA. K.
Edited by London: Academic Press;
MacleanD. J.,
ScottK. J.1970; Variant forms of saprophytic mycelium grown from uredospores of Puccinia graminis f.sp.tritici. Journal of General Microbiology 64:19–27
MacleanD. J.,
ScottK. J.1976; Identification of glucitol (sorbitol) and ribitol in a rust fungus, Puccinia graminis f.sp.tritici. Journal of General Microbiology 97:83–89
MannersJ. M.,
MacleanD,
ScottK. J.1981; Carbohydrate metabolism in axenic cultures of Puccinia graminis. Abstract of the 13th International Botanical Congress, Sydney, Australia p. 236
MarechalL. R.,
BelocopitowE.1972; Metabolism of trehalose in Euglena gracilis. I. Partial purification and some properties of trehalose phosphorylase. Journal of Biological Chemistry 247:3223–3228
MitchellD.,
ShawM.1968; Metabolism of glucose-l4C, pyruvate-14C, and mannitol-l4C by Melampsora Uni II. Conversion to soluble products. Canadian Journal of Botany 46:453–460
SmithD.,
MuscatineL.,
LewisD.1969; Carbohydrate movement from autotrophs to heterotrophs in parasitic and mutualistic symbiosis. Biological Reviews 44:17–90
SuekaneM.,
MasakiT.,
ChikakaT.1978; Physico-chemical properties and enzymatic properties of purified glucose isomerases from Streptomyces olivochromogenes and Bacillus stearothermophilus. Agricultural and Biological Chemistry 42:909–918
SweeleyC. C.,
BentleyR.,
MakitaM.,
WellsW. W.1963; Gas-liquid chromatography of tri-methylsilyl derivatives of sugars and related substances. Journal of the American Chemical Society 85:2497–2507