Nitrate Reductase Profiles in Leaves of Tall Morningglory Seedlings

Weed Science ◽  
1973 ◽  
Vol 21 (6) ◽  
pp. 561-564 ◽  
Author(s):  
Donald S. Galitz

Nitrate reductase activity of seed leaves and the first three true leaves of tall morningglory [Ipomoea purpurea (L.) Roth] was shown to increase rapidly initially then gradually decrease. The greatest level of reductase activity of each true leaf was reached at the fourth to fifth day after unfolding. A subsequent leveling off of enzyme activity corresponded to the acceleration of leaf growth. Leaf nitrates were correlated with enzyme activity. The sum of leaf activities was used to estimate the total reductive capacity of the plant leaf tissue at each sampling date.

1989 ◽  
Vol 67 (3) ◽  
pp. 750-753 ◽  
Author(s):  
Iwan Ho

Seventeen isolates, encompassing five genera and eight species of ectomycorrhizal fungi, were compared for acid phosphatase, alkaline phosphatase, and nitrate reductase activity. Isolates within species differed in enzyme activity and isozyme patterns by host specificity and site (as exemplified by the genus Suillus). Host and site may have affected phosphatase enzyme activity. Generally, the Douglas-fir associates, which dominate in mesic sites, have higher acid phosphatase activity than pine associates, which mostly occupy xeric sites; however, pine associates from mesic sites also have higher acid phosphatase activity (e.g., S. tomentosus). In four isolates of Amanita muscaria, the effect of site was also apparent. Two of them, which have significantly higher acid phosphatase activity than the others, were isolated from mesic sites. The isozyme pattern of the genus Suillus appeared to be separated by host groups. Other isolates with only one species also differed more or less by host groups. They shared at least one band within host groups, except for the two isolates of Paxillus involutus from different hosts. The P. involutus S-403 isolated from an orchard showed much higher nitrate reductase activity than all other isolates. No apparent differences in nitrate reductase activity were found between the other isolates.


2019 ◽  
Vol 10 (1) ◽  
pp. 186-194
Author(s):  
Ewerton Gewehr ◽  
Otávio De Oliveira Corrêa ◽  
Anna Dos Santos Suñé ◽  
Gabriel Bandeira Duarte ◽  
Luciano Do Amarante ◽  
...  

The aim of this study was to analyze the effects of molybdenum and inoculant application via seed treatment in soybean, and their role in the nitrate reductase enzyme activity, agronomic traits and physiological quality of the produced seeds. The experiment was conducted at the Federal University of Pelotas (UFPel), Rio Grande do Sul state, Brazil. The treatments were shaped by five doses of molybdenum (zero; 16; 32; 48; 64 g.100kg-1 of seeds) combined with the presence and absence of liquid inoculant (Bradyrhizobium japonicum), at a dose of 200 mL per 100 kg of seeds. The evaluations of nitrate reductase activity, agronomic traits and physiological seed quality were performed in the present work. The measured agronomic traits were: plant height, number of pods per plant, number of seed per plant and thousand-seed weight. Standard germination test was executed to evaluate the produced seed viability. First germination counting, accelerated aging test, cold test, plantlet shoot and root length, plantlet shoot and root dry mass, and field seedling emergence were utilized to measure the seed vigour. Molybdenum, both in presence and absence of inoculant, positively influenced the enzymatic activity, for both vegetative and reproductive stages. The addition of inoculant and molybdenum provided increase in the vigour of the produced seeds. The enzyme activity was positively correlated with the agronomic traits and vigour tests. The addition of inoculant and molybdenum in the seed treatment provides a better expression of nitrate reductase activity and vigour of the produced seeds.


1982 ◽  
Vol 68 (1) ◽  
pp. 23-28 ◽  
Author(s):  
Abdelbaset Anwer El-Aaser ◽  
Mahmoud Mohamed El-Merzabani ◽  
Nadia Ahmed Higgy ◽  
Abdel E. El-Habet

A correlation was obtained between a positive nitrite test in urine and the severity of urinary bacterial infection. Bacteria isolated from the urine of bilharzial or bladder cancer patients were found to be rich in nitrate reductase activity. « Escherichia coli » was the most common microorganism isolated from these specimens. Urine and several urinary constituents activate bacterial nitrate reductase. β-Glucuronidase activity in the urine of patients with chronic « Schistosoma haematobium » infection and bladder cancer was measured and shown to be significantly greater than that of urine of normal control subjects. Urinary bacterial infection was shown to be the source of the increased urinary level of enzyme activity at pH 7.0.


2014 ◽  
Vol 57 (4) ◽  
pp. 457-463 ◽  
Author(s):  
S. K. Sinha ◽  
H. S. Srivastava ◽  
S. N. Mishra

The effect of Pb on nitrate reductase activity, protein, total organic nitrogen and on the chlorophyll content in excised and intact leaf tissues of <em>Pisum sativum</em> was examine. Enzyme activity assayed in vitro or in vivo in the excised leaves showed marked increase at lower concentrations of Pb while being inhibited at higher concentrations. In intact leaf tissues, the enzyme activity (in vivo or in vitro) was unaffected at lower concentrations but was inhibited at higher concentrations of Pb. Chlorophyll, carotenoids (non-nitrogenous pigments), soluble protein and organic nitrogen contents remained almost unaffected at all concentrations of Pb tested. It seems that nitrate reductase has a different response towards Pb pollution in this species, which is more tolerant to heavy metal pollution, especially Pb.


1984 ◽  
Vol 30 (7) ◽  
pp. 890-893 ◽  
Author(s):  
Rachel Gollop ◽  
Yael J. Avissar

Nitrate reductase activity is expressed in bacteroids of peanut nodules but is absent in log phase cultures of Rhizobium sp. grown in the absence of nitrate. The assay of enzyme activity in free-living cells in vivo revealed a brief period of activity in early stationary phase and a recovery of activity upon prolonged microaerobic incubation of stationary cell suspensions. The expression of enzyme activity did not necessitate concurrent differentiation of rhizobia to bacteriods or the induction of nitrogenase.


1981 ◽  
Vol 59 (4) ◽  
pp. 536-541 ◽  
Author(s):  
L. P. Bush ◽  
J. E. Legget ◽  
M. J. King ◽  
J. E. Vincent

Tall fescue (Festuca arundinacea Schreb.) seedlings were grown in an intermittently irrigated gravel culture system in the greenhouse. Nutrient molybdate levels were 0, 0.1, or 0.21 μequiv./L with sulfate levels of 0 to 1.0 mequiv./L. Leaf tissue was harvested 28, 42, and 49 days after seeding. Molybdenum content of leaf tissue increased with increased solution Mo concentration. Increased solution SO42− levels increased tissue S and nitrate reductase activity (NRA), but decreased tissue Mo and NO3− content. When low tissue S was limiting NRA, and when Mo and NO3− were available, NRA was not increased by 2- to 4-h incubations of leaf tissue in SO42− solution. The MoO42− × SO42− interaction for tissue Mo concentration was significant and the effect of SO42− was relatively greater in the presence of Mo than in the absence of Mo.99Mo root uptake studies indicated the first increment of SO42− added to nutrient solution results in the greatest reduction in Mo accumulation. The data indicated that the greatest effect of SO42− on leaf Mo levels occurred during the absorption process with small reduction of Mo translocated from root to leaf tissue.


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