Natural 15N Abundance of NH4+, Amide N, and Total N in Various Fractions of Nodules of Peas, Soybeans and Lupins

1989 ◽  
Vol 16 (4) ◽  
pp. 305 ◽  
Author(s):  
G Shearer ◽  
DH Kohl
Keyword(s):  
Protein Synthesis ◽  
Glycine Max ◽  
Amino Acid ◽  
Pisum Sativum ◽  
Root Nodules ◽  
Lupinus Luteus ◽  
Total N ◽  
Isotope Discrimination ◽  
15N Enrichment ◽  
15N Abundance

Nodules of certain N2-fixing root nodules are substantially enriched in 15N compared with non-nodular tissues. This enrichment usually resides largely within bacteroids. Isotope discrimination associated with export of ammonia(um) from the bacteroid would result in 15N enrichment of NH4+ within bac- teroids. Bacteroid protein synthesis from this pool of 15N enriched NH4+ would then account for enrichment of the bacteroids. Measurements of 15N abundances of total N and free NH4+ in nodule fractions from lupins (Lupinus luteus), soybeans (Glycine max) and peas (Pisum sativum) showed this was not the case. With the inocula used in experiments reported here, lupin and soybean nodules were enriched in 15N, while pea nodules were not. There was no correlation between 15N abundances of NH4+ and total N in the nodule fractions (r= 0.445, P> 0.2). We conclude that isotope discrimination associated with ammonia(um) transport does not explain the 15N elevation of lupin and soybean nodules. We also conclude, on the basis of the large isotope effect for the equilibrium between NH4+ and NH3, that most of the ammonia(um) is exported from bacteroids as NH4+ rather than NH3. We also measured the 15N abundance of free amide N. There was a strong correlation between 15N abundances of free amide N and total N in nodule fractions (r=0.924, P<0,001), suggesting that amide N is a significant source of N to the amino acid pools from which proteins are synthesised.

scholarly journals The cDNA cloning of a pea (Pisum sativum) seed lipoxygenase. Sequence comparisons of the two major pea seed lipoxygenase isoforms

1989 ◽  
Vol 264 (3) ◽  
pp. 929-932 ◽  
Author(s):  
P M Ealing ◽  
R Casey
Keyword(s):  
Glycine Max ◽  
Amino Acid ◽  
Pisum Sativum ◽  
Amino Acid Sequence ◽  
Cdna Cloning ◽  
Soya Bean ◽  
Its Sequence ◽  
Cloning And Sequencing ◽  
Sequence Comparisons ◽  
Pea Seed

Cloning and sequencing of two cDNAs from mRNA of maturing pea (Pisum sativum) seeds allowed the deduction of the complete amino acid sequence of a lipoxygenase polypeptide which is most similar to that of soya-bean lipoxygenase 2. The predicted Mr of this polypeptide is 97134, and its sequence permits comparisons between the lox2-type and the lox3-type lipoxygenase isoforms from pea and soya bean (Glycine max).

The early morphogenesis of Glycine max and Pisum sativum root nodules

1979 ◽  
Vol 57 (23) ◽  
pp. 2603-2616 ◽  
Author(s):  
William Newcomb ◽  
David Sippell ◽  
R. L. Peterson
Keyword(s):  
Glycine Max ◽  
Pisum Sativum ◽  
Mitotic Activity ◽  
Root Nodules ◽  
Central Zone ◽  
Infected Tissue ◽  
Cortical Cells ◽  
Central Mass ◽  
Root Hair Cell ◽  
Infected Root

The development of preemergent and early emergent stages of soybean (Glycine max) and garden pea (Pisum sativum) root nodules has been studied utilizing the superior preservation and resolution obtained by noncoagulative fixatives and subsequent embedding in plastic. In both species, extensive mitotic activity and cytological changes occur in the root cortical cells while the infection thread is restricted to the infected root hair cell. In soybean the central mass of infected tissue is derived mainly from the outer layer of cortical cells whereas the inner cortical cells contribute extensively to the infected tissue of the pea nodules. The temporal and spatial patterns of mitosis differ in the nodules of the two species. Mitotic activity is restricted to a nodule meristem and occurs over a period of many weeks in pea nodules. In soybean nodules, mitotic activity occurs throughout the central zone and before decreasing, persists over a period of a few weeks. The timing and distribution of mitotic activity affects nodule morphogenesis.

Effects of early amino acid administration during total parenteral nutrition on protein metabolism in pre-term infants

1992 ◽  
Vol 82 (2) ◽  
pp. 199-203 ◽  
Author(s):  
R. A. van Lingen ◽  
J. B. van Goudoever ◽  
I. H. T. Luijendijk ◽  
J. L. D. Wattimena ◽  
P. J. J. Sauer
Keyword(s):  
Amino Acids ◽  
Protein Synthesis ◽  
Birth Weight ◽  
Amino Acid ◽  
Protein Breakdown ◽  
Protein Balance ◽  
15N Enrichment ◽  
Group A ◽  
Group B ◽  
Acid Administration

1. We investigated the effects of starting amino acid administration on post-natal day 2 on protein turnover and nitrogen balance in appropriate-for-gestational-age, very-low-birth-weight infants. Eighteen infants were divided into two groups. Group A received from day 2 onwards an amino acid solution, whereas group B started on this solution after day 4. Both groups were exclusively parenterally fed, 200 kJ day−1 kg−1 on post-natal days 3 and 4. Group A (birth weight 1.5 ± 0.3 kg) received 4.6 g of glucose, 1.9 g of fat and 2.3 g of amino acids day−1 kg−1 body weight. Group B (birth weight 1.4 ± 0.2 kg) received 7.0 g of glucose and 1.9 g of fat day−1 kg−1 body weight. 2. At post-natal day 3, a primed constant infusion of 3 mg of [15N]glycine day−1 kg−1 was given. Protein flux, protein synthesis and protein breakdown were calculated from the 15N enrichment in urinary ammonia. In five out of nine infants in group B no plateau of 15N enrichment in urinary urea could be detected, whereas in group A two out of nine infants did not reach a plateau. For this reason we did not use the end product urea for our calculations. 3. The administration of the amino acids resulted in a higher protein flux (6.9 ± 1.5 g day−1 kg−1 versus 5.2 ± 0.9 g day−1 kg−1) and a higher protein synthesis rate (6.0 ± 1.4 g day−1 kg−1 versus 4.6 ± 0.8 g day−1 kg−1) in group A. There was no statistically significant difference in protein breakdown. The administration of amino acids reversed a negative protein balance (−0.6 ± 0.2 g day−1 kg−1) into a positive one (1.4 ± 0.2 g day−1 kg−1. No adverse effects of the amino acid infusion were seen. 4. We conclude that the early introduction of amino acids has, even at this relatively low energy intake of 200 kJ day−1 kg−1, a positive effect on protein balance by increasing protein synthesis.

scholarly journals Molecular properties of lupin and serradella leghaemoglobins

1972 ◽  
Vol 127 (1) ◽  
pp. 309-314 ◽  
Author(s):  
W. J. Broughton ◽  
M. J. Dilworth ◽  
C. A. Godfrey
Keyword(s):  
Molecular Weight ◽  
Amino Acid ◽  
Cellulose Acetate ◽  
Root Nodules ◽  
Deae Cellulose ◽  
Lupinus Luteus ◽  
Terminal Amino Acid ◽  
Prosthetic Group ◽  
Terminal Amino ◽  
Ornithopus Sativus

1. Leghaemoglobins were extracted from the root nodules of lupin (Lupinus luteus L.) and serradella (Ornithopus sativus Brot.) plants and fractionated into different leghaemoglobin components on DEAE-cellulose–acetate columns. 2. The first two fractions eluted from columns loaded with either lupin or serradella leghaemoglobins were in the Fe3+ oxidation state. 3. These components have protohaem IX as the prosthetic group and glycine as the N-terminal amino acid. 4. Other properties are: lupin component I, pI5.08, molecular weight 19000; lupin component II, pI5.13, molecular weight 20600; serradella component I, pI5.00, molecular weight 17500; serradella component II, pI5.05, molecular weight 19100. 5. Leghaemoglobins are thus heterogeneous with respect to size and charge.

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