ALBERT — All Library Books, journals and Electronic Records Telegrafenberg

1

Electronic Resource

Metabolism of some amino acids in relation to the photorespiratory nitrogen cycle of pea leaves (1986)

Ta, T. C. ; Joy, K. W.

Springer

Planta 169 (1986), S. 117-122

add to mindlist on the mindlist

Details

ISSN: 1432-2048

Keywords: Amino acid metabolism ; Glycine synthesis ; Nitrogen cycle ; Photorespiratory N cycle ; Pisum (photorespiratory N cycle)

Source: Springer Online Journal Archives 1860-2000

Topics: Biology

Notes: Abstract 15N-labelled (amino group) asparagine (Asn), glutamate (Glu), alanine (Ala), aspartate (Asp) and serine (Ser) were used to study the metabolic role and the participation of each compound in the photorespiratory N cycle ofPisum sativum L. leaves. Asparagine was utilised as a nitrogen source by either deamidation or transamination, Glu was converted to Gln through NH3 assimilation and was a major amino donor for transamination, and Ala was utilised by transamination to a range of amino acids. Transamination also provided a pathway for Asp utilisation, although Asp was also used as a substrate for Asn synthesis. In the photorespiratory synthesis of glycine (Gly), Ser, Ala, Glu and Asn acted as sources of amino-N, contributing, in the order given, 38, 28, 23, and 7% of the N for glycine synthesis; Asp provided less than 4% of the amino-N in glycine. Calculations based on the incorporation of15N into Gly indicated that about 60% (Ser), 20% (Ala), 12% (Glu) and 11% (Asn) of the N metabolised from each amino acid was utilised in the photorespiratory nitrogen cycle.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1007/BF01369782

Permalink

	Location	Call Number	Expected	Availability

Others were also interested in ...

Paper (German National Licenses)

Fulltext

2

Electronic Resource

Estimation of nitrogen fixation and transfer from alfalfa to associated grasses in mixed swards under field conditions (1989)

Burity, H. A. ; Ta, T. C. ; Faris, M. A. ; [et al.]

Springer

Plant and soil 114 (1989), S. 249-255

add to mindlist on the mindlist

Details

ISSN: 1573-5036

Keywords: alfalfa ; bromegrass ; N fixation ; N transfer ; timothy

Source: Springer Online Journal Archives 1860-2000

Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition

Notes: Abstract Fixation and transfer of nitrogen (N) from alfalfa (Medicago sativa L.) to different grass species including timothy (Phleum pratense L.) and bromegrass (Bromus inermis Leyss) were studied under field conditions, using the15N dilution technique. The percentage of alfalfa N derived from fixation (%NF) increased throughout the growing seasons and ranged from 62 to 83%. Nitrogen transfer (NT) from alfalfa to associated grasses was evident and contributed 26,46 and 38% of the total annual N yield of associated grasses or represented absolute amounts of 5, 20 and 19 kg N ha−1 during the first, second and third year, respectively. The gradual and consistent percentage of NT that occurred before first harvest indicated that this transfer is a result of a direct excretion of N compounds from alfalfa root systems. Decomposition of root and nodule debris seems to contribute to the NT from alfalfa to associated grasses in the later cuts. All grass species benefitted similarly from alfalfa, although earlier maturing species with greater competitive ability were slightly more responsive.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1007/BF02220805

Permalink

	Location	Call Number	Expected	Availability

Others were also interested in ...

Paper (German National Licenses)

Fulltext

3

Electronic Resource

Utilization of carbon and nitrogen reserves of alfalfa roots in supporting N2-fixation and shoot regrowth (1990)

Ta, T. C. ; Macdowall, F. D. H. ; Faris, M. A.

Springer

Plant and soil 127 (1990), S. 231-236

add to mindlist on the mindlist

Details

ISSN: 1573-5036

Keywords: carbon and nitrogen reserves ; carbon and nitrogen utilization ; Medicago sativa ; nitrogen fixation

Source: Springer Online Journal Archives 1860-2000

Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition

Notes: Abstract Perennial legume such as alfalfa have the capacity to sustain shoot regrowth and some nodule N2-fixation after removal (‘cutting’) of shoots which contain practically all of the plant's photosynthetic capacity. The role of the roots in supporting these processes has not been fully described. Measurements were made of the nodules' responses to removal of shoots from 8-week-old seedlings in terms of N2-fixation, as nitrogenase activity (NA) measured as acetylene reduction, dark CO2 fixation, measured as in vitro phosphoenolpyruvate carboxylase (PEPC) activity, and total non-structural carbohydrate (NSC) content. These properties decreased and recovered in that sequence, which suggests that nodule NSC supported the substrate requirements of NA and PEPC immediately after cutting. The utilization and redistribution or root carbon and nitrogen, prelabeled with 14C and 15N, were also followed after cutting 8-week-old alfalfa seedlings. In the first 2 weeks of regrowth 12% of root C and 25% of root N were transferred for incorporation into new shoots. Up to 40% of the root C was used for plant respiration to support 28 days of shoot regrowth and N2-fixation. The decline of N2-fixation was slower after cutting and its minimum activity rose up 45% of pre-cut activity as root reserves were built up with plant age. Therefore, the stored reserves of nodulated roots play an important role in support of N2-fixation after cutting.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1007/BF00014430

Permalink

	Location	Call Number	Expected	Availability

Others were also interested in ...

Paper (German National Licenses)

Fulltext

4

Electronic Resource

Evaluation of15N methods to measure nitrogen transfer from alfalfa to companion timothy (1989)

Ta, T. C. ; Faris, M. A. ; Macdowall, F. D. H.

Springer

Plant and soil 114 (1989), S. 243-247

add to mindlist on the mindlist

Details

ISSN: 1573-5036

Keywords: alfalfa ; direct15N2 method ; leaf labeling method ; 15N dilution method ; N balance method ; N transfer ; timothy

Source: Springer Online Journal Archives 1860-2000

Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition

Notes: Abstract Four different methods: direct15N2 exposure, legume leaf labeled with15N,15N dilution and total N balance were applied to assess the nitrogen transfer (NT) from alfalfa to companion timothy. Evidence of NT was obtained in all cases, which represents about 3% of total N fixed by alfalfa or 10% of N content in timothy at the first cycle of growth. All the three15N methods gave identical results, while the conventional calculation of NT from the difference of N content in timothy from mixture and monoculture resulted in an over-estimation. The advantages and disadvantages of each method as applied to field conditions are discussed.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1007/BF02220804

Permalink

	Location	Call Number	Expected	Availability

Others were also interested in ...

Paper (German National Licenses)

Fulltext

5

Electronic Resource

Effects of environmental conditions on the fixation and transfer of nitrogen from alfalfa to associated timothy (1988)

TA, T. C. ; Faris, M. A.

Springer

Plant and soil 107 (1988), S. 25-30

add to mindlist on the mindlist

Details

ISSN: 1573-5036

Keywords: alfalfa ; day length ; light intensity ; nitrogen fixation ; nitrogen transfer ; temperature ; timothy

Source: Springer Online Journal Archives 1860-2000

Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition

Notes: Abstract Nitrogen fixation (NF) by alfalfa and nitrogen transfer (NT) from alfalfa to associated timothy was studied under different environmental conditions in controlled growth chambers, using the15N dilution technique. Evidence was obtained of NT from alfalfa to the associated timothy. Conditions that favored NF by alfalfa resulted in an increase in its NT. Of 3 different temperature regimes (25/20, 16/14, and 12/9°C day/night), 16–25/14–20°C was the best range for NF by alfalfa and resulted in the greatest NT. High light intensity (550 uE.m−2.sec−1) and long days (16–20 h) also caused increased NF by alfalfa and benefitting timothy more than in a regime of low light intensity (by shading 50% or 75%) or short days (12/12 or 16/8 h day/night). When the inoculated (Rhizobium meliloti) root systems of plants were kept free from other microorganisms (axenic condition) to minimize possible decomposition of dead tissues, lower NT from alfalfa was observed, especially at later cuts, compared to non-axenic plants. This suggests that both direct excretion and decomposition of dead alfalfa tissues are sources of N benefit from alfalfa to associated timothy.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1007/BF02371540

Permalink

	Location	Call Number	Expected	Availability

Others were also interested in ...

Paper (German National Licenses)

Fulltext

6

Electronic Resource

Species variation in the fixation and transfer of nitrogen from legumes to associated grasses (1987)

Ta, T. C. ; Faris, M. A.

Springer

Plant and soil 98 (1987), S. 265-274

add to mindlist on the mindlist

Details

ISSN: 1573-5036

Keywords: Alfalfa ; Birdsfoot trefoil ; Bromegrass ; Nitrogen fixation ; Nitrogen transfer ; Orchardgrass ; Red clover ; Red fescue ; Tall fescue ; Timothy

Source: Springer Online Journal Archives 1860-2000

Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition

Notes: Summary Three legume species (alfalfa, red clover, and birdsfoot trefoil) in combination with five grass species (timothy, bromegrass, red fescue, tall fescue, and orchardgrass) were used to study N transfer in mixtures, using the 15N dilution technique. The advantage of grass-legume mixtures was apparent. Total herbage and protein yields of grasses in mixtures were higher than those alone, especially at the later cuts. This benefit of mixed cropping is mainly due to N transfer from legumes to associated grasses. N2-fixation and N transfer by alfalfa rated highest, red clover intermediate, and birdsfoot trefoil lowest. The importance of each pathway of N transfer from legumes appeared to differ between species. Alfalfa and red clover excreted more N than trefoil, while the latter contributed more N from decomposition of dead nodule and root tissue. The greatest advantage from a grass-legume mixture, with respect to the utilization of N released from the legume, varied with early maturing tall fescue (Kentucky 31), orchardgrass (Juno), and bromegrass (Tempo), to intermediate timothy (Climax), and least with late maturing red fescue (Carlawn).

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1007/BF02374830

Permalink