Document Detail

Nitrate Uptake and Assimilation by Wheat Seedlings during Initial Exposure to Nitrate.
MedLine Citation:
PMID:  16659219     Owner:  NLM     Status:  PubMed-not-MEDLINE    
Nitrate uptake, reduction, and translocation were examined in intact, 14-day-old, nitrogen-depleted wheat (Triticum vulgare var. Knox) seedlings during a 9-hour exposure to 0.2 mm Ca (NO(3))(2). The nitrate uptake rate was low during the initial 3-hour period, increased during the 3- to 6-hour period, and then declined. By the 3rd hour, 14% of the absorbed nitrate had been reduced, and this increased to 36% by the 9th hour. Shoots accumulated reduced (15)N more rapidly than roots and the ratio of reduced (15)N to (15)N-nitrate was higher in the shoots. A significant proportion of the total reduction occurred in the root system under these experimental conditions. Accumulation of (15)N in ethanol-insoluble forms was evident in both roots and shoots by the 3rd hour and, after 4.5 hours, increased more rapidly in shoots than in roots.An experiment in which a 3-hour exposure to 0.2 mm Ca ((15)NO(3))(2) was followed by a 12-hour exposure to 0.2 mm Ca ((14)NO(3))(2) revealed a half-time of depletion of root nitrate of about 2.5 hours. A large proportion of this depletion, however, was due to loss of (15)N-nitrate to the ambient (14)N-nitrate solution. The remaining pool of (15)N-nitrate was only slowly available for reduction. Total (15)N translocation to the shoot was relatively efficient during the first 3 hours after transfer to Ca ((14)NO(3))(2) but it essentially ceased after that time in spite of significant pools of (15)N-nitrate and alpha-amino-(15)N remaining in the root tissue.
D A Ashley; W A Jackson; R J Volk
Related Documents :
25211109 - Pollen-ovule relation in adesmia tristis and reflections on the seed-ovule ratio by int...
15887389 - Nitrate-nitrite toxicity in cattle and sheep grazing dactyloctenium radulans (button gr...
18325029 - Growth, activity and temperature responses of ammonia-oxidizing archaea and bacteria in...
18209289 - Nitrate and bacterial contamination in well waters in vinh phuc province, vietnam.
12733579 - Biological denitrification in a continuous-flow pilot bioreactor containing immobilized...
20669719 - Precipitation of ammonium from concentrated industrial wastes as struvite: a search for...
24311129 - Acclimation of photosynthesis to increasing atmospheric co2: the gas exchange perspective.
1910869 - The epidemiology of toxic stews.
11712599 - Measurement of in situ phytoextraction of zinc by spontaneous metallophytes growing on ...
Publication Detail:
Type:  Journal Article    
Journal Detail:
Title:  Plant physiology     Volume:  55     ISSN:  0032-0889     ISO Abbreviation:  Plant Physiol.     Publication Date:  1975 Jun 
Date Detail:
Created Date:  2010-06-29     Completed Date:  2010-06-29     Revised Date:  2010-09-15    
Medline Journal Info:
Nlm Unique ID:  0401224     Medline TA:  Plant Physiol     Country:  United States    
Other Details:
Languages:  eng     Pagination:  1102-6     Citation Subset:  -    
Department of Soil Science, North Carolina State University, Raleigh, North Carolina 27607.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

Previous Document:  Perithecial Formation in Gelasinospora reticulispora: IV. Action Spectra for the Photoinduction.
Next Document:  Parthenocarpic Fruit Development from Grafted Ovaries of Cucuminis sativus L.