scholarly journals Effects of growth retarding compounds on chlorophyll accumulation and nitrate reductase activity in nitrate induced cucumber cotyledons

2015 ◽  
Vol 42 (3) ◽  
pp. 431-439 ◽  
Author(s):  
J. S. Knypl

Cotyledons were excised from 5-day old etiolated cucumber seedlings and .grown for 24 or 48 h in solutions of plant growth retardants: AMO-1618,B-Nine, CCC and phosfon D, supplemented with KNO<sub>3</sub> (10<sup>-2</sup>M) in light. Nitrate reductase (NR) activity was determined <i>in vivo</i>. CCC and Phosfon D at high concentrations had no effect on nitrate reductase activity in 24 h tests. CCC at 5xl0<sup>-2</sup> M enhanced NR activity in longer 48 h tests; Phosfon D was inhibitory in that case. AMO-1618 markedly decreased NR activity. B-Nine strikingly enhanced NR activity in KNO<sub>3</sub> induced cytoledons; the effect was positively correlated with the concentration of B-Nine. Ali the compounds inhibited chlorophyll synthesis.

1978 ◽  
Vol 58 (2) ◽  
pp. 283-285 ◽  
Author(s):  
D. G. PATRIQUIN ◽  
J. C. MacKINNON ◽  
K. I. WILKIE

Denitrification in soil around the bases of corn stalks, determined by the "acetylene blockage technique," exhibited a general trend of decline from June to September. Leaf nitrate reductase activity, determined by an in vivo assay procedure, was low in June and July, and then exhibited a pronounced maximum at the time of tasselling.


2015 ◽  
Vol 38 (4) ◽  
pp. 309-311
Author(s):  
Priyanshu Sharma ◽  
S.P. Chaukiyal ◽  
Meenu Sengar

The combination of different substrate concentrations (0.05M, 0.10M, 0.15M, 0.20M and 0.25M, KNO3) with different pH of phosphate buffer (0.10 M and 0.20 M, KH2PO4 of the pH 7.0, 7.5, 7.6, 7.7, and 7.8) solutions were tried for in-vivo nitrate reductase activity of Adenanthera microsperma leaves. Maximum nitrate reductase activity was observed in the combination of buffer solution (0.20M KH2PO4) having pH 7.7 and substrate solution 0.20 M concentration.


2011 ◽  
Vol 183-185 ◽  
pp. 900-904
Author(s):  
Yu Wen Li ◽  
Yun Jie Wu

This paper addresses the application of improvement in vivo of traditional method for determination of nitrate reductase (NR) activity of leaves to dominant tree species in forest community of northern aspect of Changbai Mountains. It describes the NR activity of tree species related to the shade-endurance and shows that the intolerance tree species has higher NR activity. The NR of a species is also related to the ecological situation of the sites. Tree species with higher NR activities should be selected for breeding of fast growing and high yield tree species.


1978 ◽  
Vol 56 (13) ◽  
pp. 1540-1544 ◽  
Author(s):  
Albert C. Purvis

Two cultivars of soybeans (Glycine max (L.) Merr.) differing widely in their resistance to ozone were exposed to 0.5 μl/ℓ ozone for 2 h in growth chambers. In vivo nitrate reduction was depressed by more than 50% in the primary leaves of Dare, the ozone-sensitive cultivar, but was not significantly altered in Hood, the ozone-resistant cultivar. Sucrose, up to 1.5% (w/v), added to excised seedlings of the Dare cultivar during exposure to ozone eliminated the ozone depression of in vivo nitrate reductase activity and also reduced foliar injury. Addition of two glycolytic intermediates, glyceraldehyde-3-phosphate and fructose-1,6-diphosphate, to the infiltration medium recovered some in vivo nitrate reduction in treated Dare leaves. The levels of extractable nitrate reductase and glyceraldehyde-3-phosphate dehydrogenase in the primary leaves of both cultivars were unaltered by ozone fumigations. These observations led to the conclusion that ozone depression of in vivo nitrate reduction is not due to ozone inactivation of nitrate reductase or of the enzymes coupling nitrate reduction to glycolysis, but may be caused by an inadequate supply of photosynthetic sugars. It was also noted that ozone depression of in vivo nitrate reduction only occurred with treatments which subsequently caused the development of visible foliar injury.


1989 ◽  
Vol 69 (3) ◽  
pp. 919-923 ◽  
Author(s):  
A. SAUVESTY ◽  
G. GENDRON

The influence of field climate on nitrate reductase activity (NR) and development was studied in six oat varieties. Of the monitored environmental factors, only temperature had a significant influence; a temperature increase accelerated plant development and increased NR. It was found that a measure of NR activity as early as the coleoptile stage of development indicated optimal environmental conditions for reduction of nitrate nitrogen in a given genotype.Key words: Nitrate reductase activity, development, climate, oat


2019 ◽  
pp. 441-448 ◽  
Author(s):  
Eleonora Sergeyevna Davidyants

The effect of seed treatment with solutions of a purified amount of triterpene glycosides (PATG) containing, as major components, oleanolic acid glycosides – sylphiosides B, C, E, G, and extract (E) enriched with sylphiosides, from Silphium perfoliatum L. (Asteraceae) leaves on growth parameters and nitrate reductase activity (NR, EC 1.6.6.1) of 7-day winter wheat plants (Tritium aestivum L.) was studied. It was shown that, seed treatment with PATG solutions in concentrations of 0.0005 and 0.001% and E in concentrations of 0.2 and 0.4% caused an increase in the length of roots, shoots, wet and dry weight of seedlings compared to the control. The stimulating effect of these concentrations of PATG and E on the total nitrate reductase activity of the roots and leaves of seedlings has been established, and an increase in the stimulating effect of preparations on the activity NR оf against the background of substrate activation of the enzyme potassium nitrate (KNO3) was observed. The greatest increase in the total NR activity of roots and leaves of winter wheat plants was observed when PATG acted at a concentration of 0.001% and E – at a concentration of 0.4%, which amounted respectively 122 and 116%, when adding 1 ml of 50 mM KNO3 solution into the growing medium of plants – 141 and 137% relative to the control. The stimulating effect of exogenous triterpene glycosides on NR activity has been established for the first time. The obtained data allow to theoretically substantiate the possibility of practical use of triterpene glycosides and preparations based on them for the regulation of growth and nitrogen metabolism of plants.


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