scholarly journals Influence of simazine on nitrate uptake and nitrate reductase activity in Triticum aestivum (L.) and Cucumis sativus (L.) seedlings

2014 ◽  
Vol 53 (2) ◽  
pp. 247-256 ◽  
Author(s):  
Irena Jarzyńska ◽  
Józef Buczek
Keyword(s):  
Triticum Aestivum ◽  
Nitrate Reductase ◽  
Cucumis Sativus ◽  
Nitrate Uptake ◽  
Reductase Activity ◽  
Triticum Aestivum L ◽  
Probable Mechanism ◽  
Cucumis Sativus L ◽  
Photosynthesis Inhibition ◽  
Nr Activity

The influence of simazine (2-chloro-4,6-bis(ethylamine)-1,3,5-triazine) on N0<sub>3</sub>- uptake and nitrate reductase (NR) activity in wheat (<em>Triticum aestivum</em>) and cucumber (<em>Cucumis sativus</em>) seedlings was investigated. It was found that at first (up to 12 h after herbicide treatment) simazine enhanced and then inhibited NR activity in the leaves and roots of the tested plants. After seven days of growth in nutrient medium containing 2.5 and 25 µM simazine the herbicide inhibited by 25 and 70 per cent, respectively, NR activity and reduced by 30 per cent in wheat and 50 per cent in cucumber seedlings nitrate uptake. The probable mechanism of NR inhibition by simazin is discussed and it is suggested that the influence of the herbicide on NR activity may not be exclusively connected with photosynthesis inhibition.

scholarly journals SELEÇÃO DE PLANTAS QUANTIFICADORAS DE HERBICIDAS RESIDUAIS

2009 ◽  
Vol 19 ◽  
Author(s):  
ANDERSON LUIZ NUNES ◽  
RIBAS ANTONIO VIDAL
Keyword(s):  
Triticum Aestivum ◽  
Hordeum Vulgare ◽  
Cucumis Sativus ◽  
Lactuca Sativa ◽  
Avena Sativa ◽  
Raphanus Sativus ◽  
Triticum Aestivum L ◽  
Hordeum Vulgare L ◽  
Cucumis Sativus L ◽  
Lactuca Sativa L

A determinação da concentração de compostos no solo por meio de plantas quantificadoras apresenta como principal vantagem detectar somente resíduos biologicamente ativos, não havendo necessidade de instrumentos onerosos e de prévia extração dos resíduos do solo. Dessa forma, este trabalho teve como objetivo selecionar plantas quantificadoras da presença de herbicidas residuais (pré emergentes) para o uso em bioensaios. Utilizou-se delineamento experimental completamente casualizado com arranjo bifatorial 8 x 6, com cinco repetições. O fator A consistiu de espécies cultiváveis e o fator B de herbicidas aplicados em pré emergência. Os resultados evidenciaram que a sensibilidade na detecção do herbicida no solo depende da espécie utilizada. A sensibilidade das espécies Lactuca sativa L. e Raphanus sativus var. sativus L. não permitiu condições de quantificar a presença dos herbicidas atrazina, cloransulam, imazaquin, metribuzin e S-metolacloro. Raphanus sativus var. oleiferus Metzger é potencial quantificador de imazaquin e S metolacloro. Plantas de Curcubita pepo L. são promissoras na bioavaliação de metribuzin. A espécie Cucumis sativus L. mostrou-se potencial bioindicadora de cloransulan e imazaquin. Avena sativa L. apresentou-se como potencial quantificadora de imazaquin e metribuzin. Hordeum vulgare L. pode quantificar o metribuzin e Triticum aestivum L. é promissor na detecção da biodisponibilidade de atrazina.

scholarly journals Reduction of nitrates in Cucumis sativus L. seedlings I. Influence of tungsten and vanadium on absorption and reduction of nitrates

2014 ◽  
Vol 49 (3) ◽  
pp. 259-267 ◽  
Author(s):  
Józef Buczek ◽  
Ewa Kowalińska ◽  
Krystyna Kuczera
Keyword(s):  
Nitrate Reductase ◽  
Cucumis Sativus ◽  
Nitrate Reductase Activity ◽  
Reductase Activity ◽  
Plant Tissues ◽  
Inhibiting Activity ◽  
Cucumis Sativus L ◽  
Cucumber Seedlings

Investigations were conducted on the influence of tungsten (Na<sub>2</sub>WO<sub>4</sub>) and meta-vanadate (NaVO<sub>3</sub>) on uptake and reduction of nitrates by cucumber seedlings. Tungsten and vanadium almost completely inhibited nitrate reductase activity (NR) after treating the plants for 24 hours with nitrates in the presence of 10<sup>-4</sup> M WO<sub>4</sub><sup>-2</sup> and 10<sup>-3</sup> M VO<sub>3</sub><sup>-</sup>. Uptake of NO<sub>3</sub><sup>-</sup> in the presence of WO<sub>4</sub><sup>-2</sup> in this same period of time was lowered by about 50 %, while in the presence of VO<sub>3</sub><sup>-</sup> by seventy percent. The ratio of NO<sub>3</sub><sup>-</sup> absorbed to that reducted in control plants was around 3, whereas in the presence of WO<sub>4</sub><sup>-2</sup> and VO<sub>3</sub><sup>-</sup> 9 and 8 respectively. The effect of NR inhibiting activity by WO<sub>4</sub><sup>-2</sup> and VO<sub>3</sub><sup>-</sup> was significant but somewhat weaker if both inhibitors were applied to the plants 24 hours after formation of the NR system, whereas NO<sub>3</sub><sup>-</sup> uptake was subject to a slight lowering. The above data suggest that WO<sub>4</sub><sup>-2</sup> and VO<sub>3</sub><sup>-</sup> after a 24 hour application of these inhibitors to plants, primary inhibit biosynthesis and activity of NR and to a lesser extent effect NO<sub>3</sub><sup>-</sup> absorption. On the basis of results reached the Butz and Jackson (1977) hypothesis concerning the model of NO<sub>3</sub><sup>-</sup> uptake and reduction by plant tissues is discussed.

RELATIONS BETWEEN NITRATE REDUCTASE ACTIVITY AND NITROGEN ACCUMULATION IN SOYBEANS

1976 ◽  
Vol 56 (2) ◽  
pp. 377-384 ◽  
Author(s):  
MIR HATAM ◽  
D. J. HUME
Keyword(s):  
Nitrate Reductase ◽  
Nitrate Reduction ◽  
Nitrate Uptake ◽  
Reductase Activity ◽  
N Uptake ◽  
Nitrogen Accumulation ◽  
Total N ◽  
Total Plant ◽  
Nr Activity

An in vivo assay for nitrate reductase (NR) activity was adapted to measure total NR activity in soybean [Glycine max (L.) Merr.] plants grown for a 29-day period indoors. Disappearance of nitrate from the nutrient solution, plant nitrate and total plant nitrogen (N) also were measured. Under the conditions of this experiment, nitrate reduction estimated from NR activities agreed closely with actual nitrate reduction. The same assay was used to measure leaf NR activities of field-grown soybeans throughout the 1971 growing season. Leaf NR activities accounted for 77 and 72% of the total N uptake in plants receiving 0 and 280 kg N as NH4NO3/ha, respectively. Measurements of nitrate and ammonium losses from soil under soybeans and under adjacent bare soil at three stages of plant development suggested that in plots receiving no fertilizer N, 86% of N uptake from the soil was in the form of nitrate. The NR activity of field-grown plants agreed well with total plant N derived from soil nitrates. Results indicated that leaf NR activities were proportional to nitrate uptake and might be used to determine amounts and seasonal patterns of nitrate uptake by soybean plants.

scholarly journals Relationships between nitrate uptake and nitrate reductase activity in Cucumis sativus L.

2014 ◽  
Vol 67 (3-4) ◽  
pp. 253-257
Author(s):  
Grażyna Kłobus ◽  
Jolanta Jerzykiewicz ◽  
Józef Buczek
Keyword(s):  
Plasma Membrane ◽  
Nitrate Reductase ◽  
Nitrate Reductase Activity ◽  
Nitrate Uptake ◽  
Plasma Membranes ◽  
Polyclonal Antibodies ◽  
Reductase Activity ◽  
Nitrate Transport ◽  
Plasma Membrane Vesicles ◽  
Cucumis Sativus L

Anti-NR IgG fragments obtained after papain digestion of polyclonal antibodies gave the positive immunological reaction with both, a soluble and plasma membrane-bound nitrate reductase. Anti-NR antibody as well as IgG fragments almost totally inhibited the nitrate reductase activity in cytosol proving a crossreaction of antibody with the catalytic site of a soluble NR. Anti-NR IgG fragments, but not undigested polyclonal antibodies affected the activity of the nitrate reductase associated with plasma membranes. Discrepancy in the action of intact antibodies and fragments obtained after they digestion were interpreted as a consequence of same differences in the ability of those molecules to the penetration through the membrane. Undigested anti-NR antibody have no effect on the nitrate uptake by intact plants, as well as by the right-side plasma membrane vesicles. On the other hand, IgG fragments of polyclonal antibodies abolished almost totally the nitrate uptake in the case of intact seedlings, but have only slight effect on the N03 uptake in plasma membranes. On the basis of above findings, some relations between nitrate uptake and its assimilation inside the cell are suggested. Since IgG fragments only slightly changed the N03 absorption in vesicles whereas the activity of plasmalemma associated nitrate reductase was strongly repressed, we concluded that the PM-NR is not structurally involved in the nitrate transport through the membrane.

scholarly journals The uptake and accumulation of phosphorous and nitrates and the activity of nitrate reductase in cucumber seedlings treated with PbCl2 or CdCl2

2014 ◽  
Vol 57 (3) ◽  
pp. 349-359 ◽  
Author(s):  
Marek Burzyński
Keyword(s):  
Heavy Metals ◽  
Nitrate Reductase ◽  
Cucumis Sativus ◽  
Nutrient Medium ◽  
Nitrate Reductase Activity ◽  
Nitrate Uptake ◽  
Reductase Activity ◽  
Control Level ◽  
Lead And Cadmium ◽  
Phosphorous Uptake

Treatment of 4-day-old cucumber (<em>Cucumis sativus</em> L.) seedlings with PbCl<sub>2</sub> or CdCl<sub>2</sub> caused a significant increase in the accumulation of heavy metals by the plants, especially in the roots. The accumulated Pb initially enhanced the uptake of phosphorous after the plants had been transferred to a nutrient medium (6, 24 hrs), but after only 48 Ins the uptake had dropped to below control level. The plants treated with Cd exhibited a constant decreased phosphorous uptake level. The accumulated lead and cadmium also inhibited nitrate uptake and the activity of nitrate reductase. It is suggested that the reason for the decreased nitrate reductase activity lay rather in the lower nitrate uptake than in a direct effect of the heavy metals on the enzyme.

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