scholarly journals Nitrate Reductase Activity in Shoots and Roots of Maize Seedlings as Affected by the Form of Nitrogen Nutrition and the pH of the Nutrient Solution

1983 ◽  
Vol 71 (3) ◽  
pp. 618-622 ◽  
Author(s):  
Konrad Mengel ◽  
Paul Robin ◽  
Louis Salsac
Keyword(s):  
Nitrate Reductase ◽  
Nutrient Solution ◽  
Nitrate Reductase Activity ◽  
Nitrogen Nutrition ◽  
Reductase Activity ◽  
Maize Seedlings

scholarly journals Nitrate reductase activity and oxalate content of sugar-beet leaves.

1972 ◽  
Vol 20 (3) ◽  
pp. 193-198
Author(s):  
F. van Egmond ◽  
H. Breteler
Keyword(s):  
Nitrate Reductase ◽  
Sugar Beet ◽  
Nutrient Solution ◽  
Nitrate Reductase Activity ◽  
Reductase Activity ◽  
Substantial Effect ◽  
Controlled Environment ◽  
Nitrate N ◽  
Carboxylate Content ◽  
The Difference

Diploid sugar beet was grown in controlled environment at 25/17 deg C in 14-h photoperiods in well aerated, regularly changed nutrient solution containing 6 meq NO3/l. When 6 leaves had been expanded, the total carboxylate content of the oldest leaf (leaf 1) was found to be 5836 meq/kg DM, while that of leaf 6 was only 2312 meq/kg; the difference was mainly due to oxalate content, which was 5236 meq/kg in leaf 1 and 1744 meq/kg in leaf 6. Nitrate-N content was about 50% higher in leaf 1 than in leaf 4. Nitrate-reductase activity fell to very low values as leaves aged. Experiments in which young and old leaf material was mixed, or oxalate at 0-4000 meq/kg DM was added to leaf samples, showed that oxalate had no substantial effect on nitrate-reductase activity. (Abstract retrieved from CAB Abstracts by CABI’s permission)

scholarly journals Nitrogen assimilation and nitrate reductase activity in tomato seedlings. II. Effect of increasing calcium doses in the presence of high magnesium concentrations on nitrate reduction and protein content

2015 ◽  
Vol 46 (2) ◽  
pp. 275-283
Author(s):  
A. Suder-Moraw ◽  
J. Buczek
Keyword(s):  
Nitrate Reductase ◽  
Protein Content ◽  
Nutrient Solution ◽  
Nitrate Reductase Activity ◽  
Calcium Concentration ◽  
Nitrogen Assimilation ◽  
Reductase Activity ◽  
Dry Weight ◽  
Tomato Seedlings ◽  
Excessive Accumulation

A 3:30 Ca:Mg ratio in the nutrient solution produces in tomato seedlings symptoms of Ca<sup>2+</sup> deficit owing to excessive accumulation of Mg<sup>2+</sup> ions and the depressed Ca<sup>2+</sup> accumulation. As a result of this a decrease in dry weight increment and protein content is observed together with inhibition of nitrate reductase activity. A doubled Ca<sup>2+</sup> dose in the nutrient solution, that is a change in the Ca:Mg ratio to 6:30 abolishes the external symptoms of Ca<sup>2+</sup> deficit and reduces Mg<sup>2+</sup> accumulation, that of Ca<sup>2+</sup> ions remaining unchanged. At the same time an enhanced activity of nitrate reductase appears, reaching values close to those in control plants. Tomato seedlings grown on a 3-fold increased Ca<sup>2+</sup> dose (Ca:Mg = 9:30) did not differ at all from the control ones. An in-crease in calcium concentration in the nutrient solution, the high magnesium dose remaining unchanged, causes enhanced K<sup>+</sup> accumulation, and this may affect nitrate absorption and reduction. It would seem that Ca<sup>2+</sup> deficit in plant tissues induced by excessive Mg<sup>2+</sup> accumulation with unsuitable Ca:Mg ratio in the nutrient solution in cause of disorders in NO<sub>3</sub> nitrogen assimilation.

Nitrate modification of photosynthesis and photoassimilate export in young nodulated soybean plants

1982 ◽  
Vol 60 (12) ◽  
pp. 2665-2670 ◽  
Author(s):  
D. J. Ursino ◽  
D. M. Hunter ◽  
R. D. Laing ◽  
J. L. S. Keighley
Keyword(s):  
Nitrogen Fixation ◽  
Nitrate Reductase ◽  
Nutrient Solution ◽  
Nitrate Reductase Activity ◽  
Reductase Activity ◽  
Nodule Development ◽  
Nitrate Availability ◽  
Data Support ◽  
Nutrient Fertilization ◽  
Soybean Plants

Soybean plants (cv. Harosoy 63) inoculated with rhizobia were germinated from seed and beginning on day 7 after planting were subjected to one of four patterns of nutrient fertilization. One group received a nutrient solution containing 5 mM nitrate, a second group received nitrate-free nutrient solution, and two other groups received nitrate-containing solution either from days 7 to 13 or from days 14 to 20. On day 21 rates of leaf photosynthetic CO2 uptake and nitrate reductase activity were measured, as well as the capacities of the leaf to export recent photosynthate and of the nodules to reduce acetylene. The data support the hypothesis that sufficient nitrate availability in the leaves of young soybean plants can modify both photosynthetic CO2 uptake and light-mediated photoassimilate export to an extent that nodule development and the capacity for nitrogen fixation are reduced.

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