Studies on the nutritional role of selenium. I. The distribution of radioactive selenium in mice

1963 ◽  
Vol 14 (5) ◽  
pp. 716 ◽  
Author(s):  
GB Jones ◽  
KO Godwin

Lucerne (Medicago sativa L.) in which the proteins were labelled with radioactive selenium was fed to mice. The distribution of 75Se among the various organs was studied. On the basis of 75Se activity per unit wet weight, the importance of the liver and kidney as metabolic sites is confirmed, and attention is directed to the pancreas, endocrines, and the stomach wall as additional sites where selenium is present in comparable concentrations. The relative importance of the above organs is supported by the results of autoradiography; in addition, this demonstrates the high concentration of 75Se in the cell nuclei, where selenium may play a fundamental role. Radioactive selenium from labelled lucerne was found in the milk of a lactating mouse within 4 hr of it being fed. Within 24 hr approximately 20% of the selenium absorbed by the dam had been transferred to the young mice through the milk.

2012 ◽  
Vol 63 (9) ◽  
pp. 734 ◽  
Author(s):  
J. H. Bouton

Pastoral agriculture is unique among the world’s agricultural production systems. Lucerne (also known as alfalfa), Medicago sativa L. subsp. sativa, has a long history of playing a very important role in pastoral agriculture. That role is expanding outside traditional hay and grazing production systems into sprouts for salads, nutritional supplements, and bioenergy feedstock. It is also the forage legume of choice for delivery of new traits via biotechnologies. The use of biotechnologies in lucerne improvement will cause re-examination of research methods and will require unique collaborations that are both interdisciplinary and even cross-institutional. The Consortium for Alfalfa Improvement (CAI) is discussed as a model for this type of collaboration. Breeding programs will continue development of cultivars with the proper fall (autumn) dormancy, a broad genetic base for pest resistance, increased local adaptation, persistence, and yield, while also adding new complex traits to these base traits. Increasing nutritional quality via down-regulation of lignin genes and increasing persistence via grazing tolerance, drought tolerance, and tolerance to acid, aluminium-toxic soils are discussed as examples of the potential impacts and challenges surrounding incorporation of complex traits. However, it is the potential for lucerne to become a major part of tropical or subtropical production systems or even an important adjunct to overcome deficiencies in the widely used perennial ryegrass (Lolium perenne L.) and white clover (Trifolium repens L.) temperate systems that begs further attention.


1991 ◽  
Vol 71 (3) ◽  
pp. 737-747 ◽  
Author(s):  
Annick Bertrand ◽  
Roger Paquin

The increased sugar and starch in crowns and roots during hardening is considered a limiting factor for the acquisition of cold tolerance in alfalfa (Medicago sativa L.). We wanted to determine the effect of a decrease in carbohydrate on cold tolerance. Alfalfa plants (Medicago sativa L.) were hardened at 1 °C or −2 °C during the day and at 10 °C or 15 °C during the dark while control plants were kept continuously at 1 °C or −2 °C. Hardening alfalfa at 10 °C and 15 °C during darkness decreased the total sugar content while it increased at 1 °C and −2 °C. However, frost tolerance and growth of the plants were not changed by raising the night temperature to 10 and 15 °C. The sugar increase corresponded in general to a starch degradation, mainly in the crowns. In plants hardened at −2 °C the proline content was higher in the leaves and lower in crowns. The opposite was observed in plants hardened at 10 and 15 °C during darkness. However, during hardening at −2 °C, we observed the desiccation of leaves and an increase in the proline content. We discuss the role of sugars as promoting agents for the acquisition of frost tolerance. Key words: Alfalfa, frost tolerance, sugars, starch, proline, hardening


1979 ◽  
Vol 63 (5) ◽  
pp. 878-881 ◽  
Author(s):  
Timothy R. Peoples ◽  
David W. Koch

Observations have been made at Rothamsted over a period of about five years upon the development of nodules on young seedlings of lucerne (Medicago sativa, L.). Some thousands of seedlings have been examined in various experiments and it was found to be the rule that the first appearance of nodules coincided with that of the expansion of the first true leaf. When lucerne is sown under summer glasshouse conditions, in pots of soil or sand, the seedlings are up in from 3 to 5 days, and in 8 to 12 days the first true leak becomes visible. This is at first closed, but in 8 to 12 days from the date of sowing it opens out (fig. 1). The following experiment illustrates the relationship between the opening of the List leak and the appearance of nodules. Lucerne seed, inoculated with nodule bacteria was sown in 12 pots, each containing about 8 pounds of sand, and these were watered with a plant-culture solution free from nitrogen.* Five days after sowing the seedlings were up, and in another 4 the first true leak, still closed, could be seen on most of them. The appearance of nodules and the opening of the first true leaves is shown in fig. 2, where each point represents observations made upon 20 seedlings, 10 from each of duplicate pots. The general agreement in the time of appearance of nodules and in the opening of the first true leaves is evident.


Author(s):  
F. S. Xia ◽  
Y. C. Wang ◽  
H. S. Zhu ◽  
J. Y. Ma ◽  
Y. Y. Yang ◽  
...  

Alfalfa seeds were primed with 0, 0.1 %, 0.3 %, 0.6 %, 1.2 %, 2.4 % and 4.8 % (W/V) concentration of borax solution for 0 (control), 3, 6, 9 and 12 h at 20°C. The results showed that the vigour of alfalfa seeds were very significantly (P less than 0.01) related to boron concentration, priming time and their interaction, they were enhanced by the opportune concentration of boron priming, but were restrained by high concentration of boron. Priming with 0.1 % boron for 6 h was the best treatment for using to improve the seed vigour of alfalfa.


1991 ◽  
Vol 68 (4) ◽  
pp. 329-335 ◽  
Author(s):  
S. PHILIPPOT ◽  
J. M. ALLIRAND ◽  
M. CHARTIER ◽  
G. GOSSE

Author(s):  
Anas Raklami ◽  
Mohamed Oubane ◽  
Abdelilah Meddich ◽  
Mohamed Hafidi ◽  
Bernd Marschner ◽  
...  

1956 ◽  
Vol 34 (12) ◽  
pp. 1704-1708 ◽  
Author(s):  
Arthur Morgan ◽  
Léo Marion

Earlier attempts to feed ornithine-2-C14 to Medicago sativa L. Grimm had failed to produce any labelled stachydrine. Repetition of the work has confirmed this result, and a study of the amino acids present in the plant has shown that the proline also was inactive. Feeding pyridoxine with ornithine-2-C14 to the plant did not produce active stachydrine, but gave rise to radioactive proline. Of the other amino acids present, glycine, aspartic acid, and glutamic acid were also active. A similar feeding experiment with radioactive ornithine and pyridoxine, using older plants, also failed to produce active stachydrine although, as before, the proline was active and so was the keto acids fraction.The results seem to indicate that ornithine may be the precursor of stachydrine, but that the transformation to proline and the methylation to the alkaloid occur at a later stage of growth, possibly at seed formation.


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