THE METABOLISM OF PROPIONATE BY WHEAT STEM RUST UREDOSPORES

1963 ◽  
Vol 41 (3) ◽  
pp. 737-743 ◽  
Author(s):  
H. Reisener ◽  
A. J. Finlayson ◽  
W. B. McConnell ◽  
G. A. Ledingham
Keyword(s):  
Carbon Dioxide ◽  
Amino Acids ◽  
Glutamic Acid ◽  
Stem Rust ◽  
Water Extract ◽  
Hot Water ◽  
Insoluble Residue ◽  
Soluble Carbohydrates ◽  
Wheat Stem Rust ◽  
Carbon 14

When uredospores of wheat stem rust were shaken for 3 hours with phosphate buffer (pH 6.2) containing propionate-1-C14, -2-C14, or -3-C14, about 55% of the carbon-14 was removed from the solution. With propionate-1-C14, most of the carbon-14 taken up was released as carbon dioxide-C14, whereas about 20% and 31% of propionate carbon 2 and carbon 3, respectively, was incorporated into the spores. The specific activity of a fraction consisting of the free amino acids of a hot-alcohol and hot-water extract of the spores increased markedly with increase in the position number of propionate in which the carbon-14 was located. A similar relation was observed for other fractions such as soluble carbohydrates, ether-soluble material, organic acids, and insoluble residue from spores. The most active amino acids isolated were glutamic acid, γ-aminobutyric acid, and alanine. Partial degradations showed that with propionate-2-C14 the carboxyl groups of glutamic acid were especially radioactive, whereas with propionate-3-C14 the internal carbons were most radioactive.It is concluded that propionate metabolism in the rust spores involved conversion of carbon 1 to carbon dioxide, and utilization of carbons 2 and 3 as acetate with carbon 2 behaving as the carboxyl carbon.

THE METABOLISM OF PROPIONATE BY WHEAT STEM RUST UREDOSPORES

1963 ◽  
Vol 41 (1) ◽  
pp. 737-743 ◽  
Author(s):  
H. Reisener ◽  
A. J. Finlayson ◽  
W. B. McConnell ◽  
G. A. Ledingham
Keyword(s):  
Carbon Dioxide ◽  
Amino Acids ◽  
Glutamic Acid ◽  
Stem Rust ◽  
Water Extract ◽  
Hot Water ◽  
Insoluble Residue ◽  
Soluble Carbohydrates ◽  
Wheat Stem Rust ◽  
Carbon 14

When uredospores of wheat stem rust were shaken for 3 hours with phosphate buffer (pH 6.2) containing propionate-1-C14, -2-C14, or -3-C14, about 55% of the carbon-14 was removed from the solution. With propionate-1-C14, most of the carbon-14 taken up was released as carbon dioxide-C14, whereas about 20% and 31% of propionate carbon 2 and carbon 3, respectively, was incorporated into the spores. The specific activity of a fraction consisting of the free amino acids of a hot-alcohol and hot-water extract of the spores increased markedly with increase in the position number of propionate in which the carbon-14 was located. A similar relation was observed for other fractions such as soluble carbohydrates, ether-soluble material, organic acids, and insoluble residue from spores. The most active amino acids isolated were glutamic acid, γ-aminobutyric acid, and alanine. Partial degradations showed that with propionate-2-C14 the carboxyl groups of glutamic acid were especially radioactive, whereas with propionate-3-C14 the internal carbons were most radioactive.It is concluded that propionate metabolism in the rust spores involved conversion of carbon 1 to carbon dioxide, and utilization of carbons 2 and 3 as acetate with carbon 2 behaving as the carboxyl carbon.

THE METABOLISM OF VALERATE-3-C14 AND -5-C14 BY WHEAT STEM RUST UREDOSPORES

1964 ◽  
Vol 42 (3) ◽  
pp. 327-332 ◽  
Author(s):  
H. Reisener ◽  
A. J. Finlayson ◽  
W. B. McConnell
Keyword(s):  
Carbon Dioxide ◽  
Amino Acids ◽  
Glutamic Acid ◽  
Stem Rust ◽  
Phosphate Buffer ◽  
Free Amino Acids ◽  
Free Amino ◽  
Methyl Groups ◽  
Wheat Stem Rust ◽  
Carbon 14

Uredospores of wheat stem rust took up about 90% of the carbon-14 present either as valerate-3-C14 or as valerate-5-C14 in M/30 phosphate buffer pH 6.2 in 3 hours. The initial valerate concentration was 0.017 mM and spores were supplied at the rate of 250 mg/30 ml of buffer. Carbon 3 of the valerate was largely respired as carbon dioxide but carbon 5 was extensively incorporated into spore components. Free amino acids contained about 40% of the radioactivity in the spores labelled with valerate-5-C14 and glutamic acid was highly labelled. Carbon 1 contained 8.1% and carbon 5, 3.8% of the carbon-14 in this glutamic acid and thus internal carbons contained 88%. The results with valerate-3-C14 and with valerate-5-C14 compare well with those of experiments done earlier with propionate-1-C14 and propionate-3-C14 respectively. It is concluded that propionate is formed from carbons 3, 4, and 5 of valerate, and thus that carbon 3 is converted to carbon dioxide, and carbons 4 and 5 to the carboxyl and methyl groups respectively of acetate.

THE METABOLISM OF PELARGONATE-1-C14 BY WHEAT STEM RUST UREDOSPORES

1965 ◽  
Vol 43 (1) ◽  
pp. 91-96 ◽  
Author(s):  
S. Suryanarayanan ◽  
W. B. McConnell
Keyword(s):  
Amino Acids ◽  
Glutamic Acid ◽  
Glyoxylate Cycle ◽  
Water Extract ◽  
Aminobutyric Acid ◽  
Pelargonic Acid ◽  
Puccinia Graminis ◽  
Wheat Stem Rust ◽  
Carbon 14 ◽  
The Glyoxylate Cycle

Uredospores of Puccinia graminis var. tritici were incubated in phosphate buffer (pH 6.2) containing pelargonic acid-1-C14. After 3 hours 97.5% of the tracer was assimilated. Fifty-five percent of this was released as C14O2 and 36.2% was incorporated into the spores. About one-half of the carbon-14 in the spores was soluble in ethanol and water, whereas nearly a third was ether extractable. The amino acid and carbohydrate fractions contained about equal amounts of carbon-14 and together accounted for two-thirds of the radioactivity in the ethanol–water extract. The organic acids were also radioactive. Glutamic acid, γ-aminobutyric acid, aspartic acid, and alanine were the most highly labelled amino acids. Fifty-three percent of the radioactivity in glutamic acid was found in carbon 1 and 46% in carbon 5. This distribution suggests β-oxidation of pelargonic acid to acetyl CoA and extensive utilization of the latter by means of the glyoxylate cycle.

UTILIZATION OF ADDED SUBSTRATES BY UREDOSPORES OF WHEAT STEM RUST

1956 ◽  
Vol 2 (6) ◽  
pp. 559-563 ◽  
Author(s):  
P. Shu ◽  
A. C. Neish ◽  
G. A. Ledingham
Keyword(s):  
Carbon Dioxide ◽  
Amino Acids ◽  
Fatty Acids ◽  
Glutamic Acid ◽  
Metabolic Activity ◽  
Stem Rust ◽  
Volatile Fatty Acids ◽  
The Other ◽  
Wheat Stem Rust ◽  
Better Than

Uredospores of wheat stem rust utilized a number of externally-supplied, labelled carbohydrates, amino acids, and volatile fatty acids. The carbon of these substrates appeared in the spore materials and in the carbon dioxide. This metabolic activity, though very weak, is definite. D-Mannose, D-mannitol, D-glucose, sucrose, and D-fructose were utilized better than the other carbohydrates. Glutamic acid gave the highest yield of carbon dioxide while the basic amino acids, L-arginine and L-lysine, were more efficiently incorporated into the spore material.

THE UTILIZATION OF AMMONIUM CHLORIDE-15N BY UREDOSPORES OF WHEAT STEM RUST

1966 ◽  
Vol 44 (11) ◽  
pp. 1511-1518 ◽  
Author(s):  
W. B. McConnell ◽  
E. W. Underhill
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Glutamic Acid ◽  
Ammonium Chloride ◽  
Stem Rust ◽  
Organic Nitrogen ◽  
Ammonia Nitrogen ◽  
Ammonium Nitrogen ◽  
Wheat Stem Rust ◽  
Carbon 14

When uredospores of wheat stem rust, Puccinia graminis van tritici (race 15B), were incubated with a 3 mM solution of ammonium chloride-15N, a significant amount of nitrogen 15 was converted into organic nitrogen. Most of this organic nitrogen 15 was found in the ethanol and water extracts, with lesser amounts in the buffer and in extracted spores.Amino acids extracted from the spores all contained excess nitrogen 15. Nitrogen 15 from the inorganic source was diluted by factors of 1.7 and 2.7 in free aspartic and glutamic acids respectively; these amino acids were the most heavily labeled with the isotope. Proline was the most weakly labeled amino acid, the nitrogen 15 being diluted by a factor of 102. Good incorporation of nitrogen 15 into glutamic acid compared to simultaneous poor incorporation into the biochemically related amino acid, proline, parallels previous observations made during carbon 14 experiments with rust uredospores.Fourteen "bound" amino acids were isolated after acid hydrolysis of extracted spores. All contained nitrogen 15, the dilution of the added ammonia nitrogen ranging from 96 for glutamic acid to 7660 for proline.The results are taken as evidence that uredospores of wheat stem rust can incorporate ammonium nitrogen into free amino acids and into proteins.

THE METABOLISM OF VALERATE-2-C14 BY UREDOSPORES OF WHEAT STEM RUST

1963 ◽  
Vol 41 (1) ◽  
pp. 1-7 ◽  
Author(s):  
H. Reisener ◽  
A. J. Finlayson ◽  
W. B. McConnell
Keyword(s):  
Carbon Dioxide ◽  
Glutamic Acid ◽  
Specific Activity ◽  
Tricarboxylic Acid Cycle ◽  
High Specific Activity ◽  
Water Soluble ◽  
Buffer Solution ◽  
Wheat Stem Rust ◽  
Carbon 14 ◽  
Water Soluble Extract

When uredospores of Puccinia graminis var. tritici race 15B were shaken in a medium containing M/30 phosphate buffer, pH 6.2, and valerate-2-C14, about 88% of the radioactivity was removed from the buffer solution in a period of 3 hours. About 40% of the carbon-14 taken from the buffer was found in a water-soluble extract of the spores and about 15% was respired as carbon dioxide. The result is compared with an earlier report that carbon 1 of valerate is more extensively released as carbon dioxide and less extensively incorporated into spore components. Glutamic acid, glutamine, γ-aminobutyric acid, and alanine of high specific activity were isolated. It was estimated from partial degradation that more than one-half of the carbon-14 of glutamic acid occurred in position 4 and that carbon 5 was very weakly labelled. Citric acid was also of high specific activity and was labelled predominantly in the internal carbons.It is concluded that respiring rust spores utilize externally supplied valerate by β-oxidation, which releases carbons 1 and 2 in a form which is metabolized as acetate by the tricarboxylic acid cycle.

EFFECT OF SHORT-CHAIN FATTY ACIDS ON RESPIRATION OF WHEAT STEM RUST UREDOSPORES

1961 ◽  
Vol 7 (6) ◽  
pp. 865-868 ◽  
Author(s):  
H. J. Reisener ◽  
W. B. McConnell ◽  
G. A. Ledingham
Keyword(s):  
Carbon Dioxide ◽  
Fatty Acids ◽  
Stem Rust ◽  
Short Chain Fatty Acids ◽  
Short Chain ◽  
Puccinia Graminis ◽  
Wheat Stem Rust ◽  
Carbon 14 ◽  
Carboxyl Carbon ◽  
Chain Fatty Acids

Fatty acids added to a suspension of wheat stem rust uredospores (Puccinia graminis var. tritici, race 15B) stimulate respiration. When compared on the basis of equal molar concentration, the utilization of oxygen by spores from wheat grown in the field or in the greenhouse is stimulated by short-chain fatty acids as follows: acetate < propionate < butyrate < valerate. The order for butyrate and valerate is reversed with spores from plants grown under artificial light. Radiotracer experiments indicate that the amount of respired carbon dioxide derived from the carboxyl carbon of the fatty acid added increases markedly with increase in chain length. The addition of exogenous acetate stimulated conversion of spore carbon to carbon dioxide, whereas valerate replaces, in part, spore material as a source of respiratory carbon. Valerate-1-C14 is almost 4 times as effective as acetate-1-C14 for labelling spore material, but the ratio of carbon-14 respired to that incorporated is 2.6 for valerate-1-C14 as compared with 1.5 for acetate-1-C14.

THE METABOLISM OF ACETATE BY WHEAT STEM RUST UREDOSPORES

1964 ◽  
Vol 42 (6) ◽  
pp. 883-888 ◽  
Author(s):  
S. Suryanarayanan ◽  
W. B. McConnell
Keyword(s):  
Carbon Dioxide ◽  
Glutamic Acid ◽  
Tricarboxylic Acid Cycle ◽  
Tricarboxylic Acid ◽  
Water Soluble ◽  
Puccinia Graminis ◽  
Acid Fraction ◽  
Wheat Stem Rust ◽  
Acid Cycle ◽  
Carbon 14

When uredospores of Puccinia graminis var. tritici (race 15B) were incubated at pH 6.2 in phosphate buffer containing either acetate-1-C14or -2-C14, about 12% of the radioactivity was removed from the solution in a period of 3 hours. Respired carbon dioxide contained about 45% and 22% of the carbon-14 taken up as acetate-1-C14and acetate-2-C14, respectively. Incorporation of carbon-14 into spore components was considerably higher with acetate-2-C14than with acetate-1-C14. With either tracer most of the radioactivity in water-soluble spore materials was accounted for in amino acids and neutral substances. Glutamic acid was particularly radioactive and accounted for about 40% of the radioactivity in the amino acid fraction. Incorporation of carbon-14 into the glutamic acid skeleton was consistent with the view that both the tricarboxylic acid cycle and the glyoxalate cycle were functioning.

THE METABOLISM OF VALERATE-2-C14 BY UREDOSPORES OF WHEAT STEM RUST

1963 ◽  
Vol 41 (1) ◽  
pp. 1-7 ◽  
Author(s):  
H. Reisener ◽  
A. J. Finlayson ◽  
W. B. McConnell
Keyword(s):  
Carbon Dioxide ◽  
Glutamic Acid ◽  
Specific Activity ◽  
Tricarboxylic Acid Cycle ◽  
High Specific Activity ◽  
Water Soluble ◽  
Buffer Solution ◽  
Wheat Stem Rust ◽  
Carbon 14 ◽  
Water Soluble Extract

When uredospores of Puccinia graminis var. tritici race 15B were shaken in a medium containing M/30 phosphate buffer, pH 6.2, and valerate-2-C14, about 88% of the radioactivity was removed from the buffer solution in a period of 3 hours. About 40% of the carbon-14 taken from the buffer was found in a water-soluble extract of the spores and about 15% was respired as carbon dioxide. The result is compared with an earlier report that carbon 1 of valerate is more extensively released as carbon dioxide and less extensively incorporated into spore components. Glutamic acid, glutamine, γ-aminobutyric acid, and alanine of high specific activity were isolated. It was estimated from partial degradation that more than one-half of the carbon-14 of glutamic acid occurred in position 4 and that carbon 5 was very weakly labelled. Citric acid was also of high specific activity and was labelled predominantly in the internal carbons.It is concluded that respiring rust spores utilize externally supplied valerate by β-oxidation, which releases carbons 1 and 2 in a form which is metabolized as acetate by the tricarboxylic acid cycle.

STUDIES ON WHEAT PLANTS USING CARBON-14 COMPOUNDS: XXI. THE METABOLISM OF GLYCINE-2-C14

1964 ◽  
Vol 42 (9) ◽  
pp. 1293-1299 ◽  
Author(s):  
W. B. McConnell
Keyword(s):  
Carbon Dioxide ◽  
Amino Acids ◽  
Glutamic Acid ◽  
Specific Activity ◽  
Total Carbon ◽  
Gluten Protein ◽  
Carbon 14 ◽  
Specific Activities

Glycine-2-C14was administered to 83-day-old wheat plants. The plants were allowed to mature fully and the carbon-14 distribution was then examined. About 80% of the radioactivity injected was recovered in the upper portions of the plant, the kernels themselves containing 66%. Proteins had a higher specific activity than other kernel constituents but the starch contained about one-half the total carbon-14 of the kernels. Glycine and serine were by far the most radioactive amino acids of the gluten protein. They had specific activities of 2720 and 2900 μc/mole C respectively while alanine, histidine, methionine, glutamic acid, and proline had specific activities ranging from 150 to 300 μc/mole C. The specific activities of carbons 1 and 2 of glycine recovered from the protein were 550 and 4900 μc/mole respectively while the specific activities of carbons 1, 2, and 3 of serine were 490, 4300, and 3100 μc/mole respectively. The results confirm previous views regarding extensive interconversion of glycine and serine in maturing wheat. Extensive labelling in carbon 3 of serine is interpreted as evidence that glycine is degraded to "active formaldehyde" and carbon dioxide.

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