Preparation of some carbon-14-labeled amino acids by radiophotosynthesis using sugar beet plant

1980 ◽  
Vol 25 (4) ◽  
pp. 471-484 ◽  
Author(s):  
M.F. Barakat ◽  
A.A. El-Gharbawy ◽  
A.N. Farag
2012 ◽  
Vol 26 (2) ◽  
pp. 177-182 ◽  
Author(s):  
Darren E. Robinson ◽  
Kristen E. McNaughton

Trials were established in 2007, 2008, and 2009 in Ontario, Canada, to determine the effect of soil residues of saflufenacil on growth, yield, and quality of eight rotational crops planted 1 yr after application. In the year of establishment, saflufenacil was applied PRE to field corn at rates of 75, 100, and 200 g ai ha−1. Cabbage, carrot, cucumber, onion, pea, pepper, potato, and sugar beet were planted 1 yr later, maintained weed-free, and plant dry weight, yield, and quality measures of interest to processors for each crop were determined. Reductions in dry weight and yield of all grades of cucumber were determined at both the 100 and 200 g ha−1rates of saflufenacil. Plant dry weight, bulb number, and size and yield of onion were also reduced by saflufenacil at 100 and 200 g ha−1. Sugar beet plant dry weight and yield, but not sucrose content, were decreased by saflufenacil at 100 and 200 g ha−1. Cabbage plant dry weight, head size, and yield; carrot root weight and yield; and pepper dry weight, fruit number and size, and yield were only reduced in those treatments in which twice the field corn rate had been applied to simulate the effect of spray overlap in the previous year. Pea and potato were not negatively impacted by applications of saflufenacil in the year prior to planting. It is recommended that cabbage, carrot, cucumber, onion, pepper, and sugar beet not be planted the year after saflufenacil application at rates up to 200 g ha−1. Pea and potato can be safely planted the year following application of saflufenacil up to rates of 200 g ha−1.


2013 ◽  
Vol 152 (1) ◽  
pp. 166-174 ◽  
Author(s):  
J. GONZÁLEZ ◽  
J. M. ARROYO ◽  
J. A. GUEVARA-GONZÁLEZ ◽  
R. MOUBI ◽  
O. PIQUER ◽  
...  

SUMMARYEffects of the correction of microbial contamination (using15N techniques) and of considering the comminution rate (kc) of particles in the rumen on effective estimates of the ruminally undegraded (RU) fraction and its intestinal effective digestibility (IED) were examined in a sample of dehydrated sugar beet pulp (DBP) generating composite samples (from rumen-incubated residues) representative of the chemical composition of RU. Tested fractions were dry matter (DM), organic matter (OM, tested only for RU), crude protein (CP) and amino acids (AA). The study was performed on three rumen and duodenum cannulated wethers fed with a 2 : 1 (fresh weight basis) chopped oat hay-to-concentrate diet supplied at 40 g DM/kg BW0·75in six equal meals per day. The DBP showed sigmoid degradation kinetics: the fractional degradation rate increased by 5·8 times as time (h) increased from 0 to∞. Thekcrate (measured in the diet concentrate) represented 5·74% of the total rumen retention time of particles. As a result, the RU of DM was over-evaluated by 6·53% whenkcwas not considered. Microbial contamination of RU was high as in DM as in CP. Therefore, the overestimation of RU of DM was increased to 12·2% when this contamination was not corrected. The lack of this correction also led to large over-evaluations of RU and IED of CP and AA. As a result, the overestimation of the intestinal digested fraction was 40·9% for CP and 45·0% for total analysed AA. This overestimation varied largely among AA (from 18·9 to 88·7%). Corrected proportions of RU and IED were also variable among AA. Hypotheses on the causes of this variability are given. Resultant changes in the AA profile of the intestinal digested protein had some negative impact on the supply of essential AA and cysteine without affecting lysine. This problem is limited because the microbial protein synthesized from DBP fermentation in the rumen is largely predominant in the AA supply to the host.


1959 ◽  
Vol 37 (1) ◽  
pp. 933-936 ◽  
Author(s):  
W. B. McConnell

Glutamic acid-1-C14 was injected into the top internode of wheat stems at a stage of growth when kernel development was rapid (71 days after seeding). The plants were harvested 31 days later when they had matured and the incorporation of carbon-14 studied. About one-third of the carbon-14 administered was found in the upper portions of the mature plants, much of the remaining radioactivity having apparently been respired. About 85% of the carbon-14 recovered was found in the kernel. The protein fractions of these were most radioactive, but an appreciable amount of carbon-14 also appeared in the starch. Glutamic acid had the highest specific activity of the amino acids isolated from the gluten, but proline and arginine were also strongly labelled. Since these three amino acids were labelled predominantly in carbon-1 their close metabolic relationship in the wheat plant seems probable.


1963 ◽  
Vol 41 (3) ◽  
pp. 737-743 ◽  
Author(s):  
H. Reisener ◽  
A. J. Finlayson ◽  
W. B. McConnell ◽  
G. A. Ledingham

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.


1965 ◽  
Vol 86 (3) ◽  
pp. 253-255 ◽  
Author(s):  
Raymond Borchers ◽  
Sarah Moenter Andersen ◽  
Judy Spelts
Keyword(s):  

1956 ◽  
Vol 34 (1) ◽  
pp. 511-519 ◽  
Author(s):  
G. H. N. Towers ◽  
D. C. Mortimer

Of the keto acids identified in leaves of sugar beet and other plants exposed to C14O2, pyruvic acid was found to be the only one labelled in light periods up to 45 sec. α-Ketoglutaric and glyoxylic acids became radioactive after about 45 sec. Radioactive hydroxypyruvate was not identified under these conditions and labelled oxaloacetate was detected only in trace amounts after 60 sec. in Scenedesmus. In contrast glycine and serine were labelled after 10 sec. under comparable conditions and aspartic acid was appreciably labelled after 30 sec. The effect on the radioactivity of the keto acids of an additional period intracer-free air, with and without light, as well as the dark incorporation of C14O2 was studied. These results are discussed in relation to the role of the ketoacids in photosynthesis. It is concluded that the synthesis of amino acids such as glycine, serine, and aspartic acid may be effected by mechanisms other than transamination in green leaves in the light.


1957 ◽  
Vol 35 (6) ◽  
pp. 365-371 ◽  
Author(s):  
E. Bilinski ◽  
W. B. McConnell

Glutamic acid, aspartic acid, and threonine isolated from the gluten of wheat plants to which acetate-1-C14 or -2-C14 was administered during growth have been degraded to determine the complete intramolecular distribution of C14. Sixty-three per cent of the activity in glutamic acid arising from acetate-1-C14 was in carbon-5 and 20% in carbon-1; glutamic acid from acetate-2-C14 contained 43% of the activity in carbon-4 and about 18% in each of carbons 2 and 3. Acetate-1-C14 resulted in labelling largely in the terminal carbons of aspartic acid, and acetate-2-C14 preferentially labelled the internal carbons. The results show that the Krebs' citric acid cycle provides a major pathway for the biosynthesis of the dicarboxylic amino acids of wheat gluten.Striking parallelism in the intramolecular distribution of carbon-14 in aspartic acid and threonine demonstrates that these amino acids are closely linked biosynthetically and is in accord with the idea that aspartic acid provides the carbon skeleton for threonine.


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