Changes in Leaf Nitrate Reductase Activity In Vivo and In Vitro During Light-Dark Transitions

1999 ◽  
Vol 8 (1) ◽  
pp. 37-40 ◽  
Author(s):  
B. K. Salalkar ◽  
R. S. Shaikh ◽  
R. M. Naik ◽  
S. V. Munjal ◽  
B. B. Desai ◽  
...  
Keyword(s):  
Nitrate Reductase ◽  
Nitrate Reductase Activity ◽  
Reductase Activity ◽  
Leaf Nitrate

SEASONAL PATTERNS OF DENITRIFICATION AND LEAF NITRATE REDUCTASE ACTIVITY IN A CORN FIELD

1978 ◽  
Vol 58 (2) ◽  
pp. 283-285 ◽  
Author(s):  
D. G. PATRIQUIN ◽  
J. C. MacKINNON ◽  
K. I. WILKIE
Keyword(s):  
Nitrate Reductase ◽  
Nitrate Reductase Activity ◽  
General Trend ◽  
Reductase Activity ◽  
Seasonal Patterns ◽  
Assay Procedure ◽  
Acetylene Blockage Technique ◽  
Acetylene Blockage ◽  
Leaf Nitrate

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.

scholarly journals Effect of lead on nitrate reductase activity and nitrate assimilation in pea leaves

2014 ◽  
Vol 57 (4) ◽  
pp. 457-463 ◽  
Author(s):  
S. K. Sinha ◽  
H. S. Srivastava ◽  
S. N. Mishra
Keyword(s):  
Enzyme Activity ◽  
Nitrate Reductase ◽  
Nitrate Reductase Activity ◽  
Organic Nitrogen ◽  
Reductase Activity ◽  
Total Organic Nitrogen ◽  
Intact Leaf ◽  
Leaf Tissues

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.

Effects of Glufosinate on Anion Uptake in Lemna gibba G 1

1989 ◽  
Vol 44 (1-2) ◽  
pp. 33-38 ◽  
Author(s):  
Gudrun D. Trogisch ◽  
Helmut Köcher ◽  
Wolfram R. Ullrich
Keyword(s):  
Nitrate Reductase ◽  
Nitrate Reductase Activity ◽  
Nitrate Uptake ◽  
Dark Respiration ◽  
Reductase Activity ◽  
Lemna Gibba ◽  
Proton Cotransport ◽  
Chlorophyll Formation

Abstract The duckweed Lemna gibba G 1 was used as a model to study inhibitory sites with the herbicide and glutamate analogue glufosinate (PPT). Growth and chlorophyll formation were partly inhibited by 25 n-M, completely suppressed by 250 (im PPT. Photosynthesis showed partial inhibition within few hours, dark respiration ( 0 2 consumption) increased already within one hour. In the presence of 1 mM PPT in the light, the ammonium pool of Lemna increased to 600% within few hours, later to 1000%. The overall amino acid pool exhibited a slower increase to 300%, the nitrate pool only a slight increase, while total phosphate remained almost unchanged. In the dark all these effects were less pronounced than in the light. Nitrate, nitrite and phosphate uptake were partially inhibited by PPT, especially after 19 h PPT pretreatment. Nitrate reductase activity in vitro, after PPT treatment in vivo, showed an inhibition similar to that of nitrate uptake. Ammonium was not taken up but released under the same conditions. The data are explained by a combined effect of PPT, by inhibition of glutamine synthetase leading to accumulation of ammonium from photorespiration and proteolysis, by membrane depolarization and inhibition of anion/proton cotransport, by secondary uncoupling of phosphorylation, and by secondary inhibition of nitrate reductase activity.

scholarly journals Effect of vanadium on nitrate reductase activity in tomato leaves

2015 ◽  
Vol 42 (2) ◽  
pp. 223-232 ◽  
Author(s):  
J. Buczek
Keyword(s):  
Nitrate Reductase ◽  
Enzyme Inhibition ◽  
Nitrate Reductase Activity ◽  
Reductase Activity ◽  
Tomato Seedlings ◽  
Low Concentrations ◽  
Edta Solution ◽  
Vanadium Ions

The activity of nitrate reductase in cell-free extracts from tomato leaves is completely inhibited by 100 μM NaVO<sub>3</sub> or VOCl<sub>2</sub>. In experiments in vivo vanadium ions inhibit the activity of the enzyme in 50 to 60 per cent. Addition of l mM vanadium to the medium on which tomato seedlings are grown causes after 24 h almost complete inhibition of nitrate reductase activity in cell-free extracts of the enzyme. Inhibition with vanadium may be abolished in experiments <i>in vitro</i> if the extract is treated with a rather concentrated EDTA solution or Sephadex G-25. The data obtained in this study indicate that vanadium ions in relatively low concentrations inhibit the activity of nitrate reductase in tomato seedlings both <i>in vivo</i> and <i>in nitro</i>.

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