Nitrate Reductase Activity During Ontogeny of the Fruit of Cashew (Anacardium occidentale L.)

1983 ◽  
Vol 10 (1) ◽  
pp. 9 ◽  
Author(s):  
CC Subbaiah ◽  
D Balasimha
Keyword(s):  
Nitrate Reductase ◽  
Organic Nitrogen ◽  
Reductase Activity ◽  
Nitrate Assimilation ◽  
Nitrate Content ◽  
Nitrogen Accumulation ◽  
Total Organic Nitrogen ◽  
Fruit Wall ◽  
Nr Activity

The in vivo nitrate reductase (NR) activity was assayed in the pedicel (apple), the fruit wall (shell) and the ovule (kernel) of cashew at 5-day intervals after fertilization. The pericarp showed high rates of enzyme activity during fresh weight accumulation, but activity remained low in the pedicel during its development. Estimation, using a graphical integration method, of total nitrate reduced by individual parts of the fruit showed that the pericarp contributed the maximum (67.5%) and the pedicel the least (7.8%) to the total nitrate assimilated in the fruit. The rate of NR activity varied with tissue nitrate content in any fruit part but was not related to the pattern of organic nitrogen accumulation except in the case of the ovule. However, NR activity of the true fruit (the nut) was accountable for about 3-4% of the total organic nitrogen present at maturity. Besides its major role in nitrate assimilation, there was evidence that the pericarp exports about 60% of its nitrogen to the seed.

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.

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 Characterization of nitrate reductase activity (NR) in foliar and radicular tissues of Physalis angulata L.: diurnal variations and protocol optimization

2019 ◽  
pp. 1120-1125
Author(s):  
Tamara Torres Tanan ◽  
Marilza Neves do Nascimento ◽  
Alismário Leite da Silva ◽  
David Santana Guimarães ◽  
Romeu da Silva Leite ◽  
...  
Keyword(s):  
Nitrate Reductase ◽  
Reductase Activity ◽  
Nitrate Assimilation ◽  
Assay Method ◽  
Physalis Angulata ◽  
Nr Activity ◽  
Assay Conditions

Nitrate reductase (NR) is the first enzyme in the nitrogen assimilation pathway. The determination of its activity requires modifications for each plant species. The goal of this work was to evaluate the variation of NR activity throughout the day and the optimization of assay conditions in foliar and radicular tissues of Physalis angulata. The analysis was done in plants cultivated in a hydroponic system at two months of age. The NR activity was based on the in vivo assay method. Enzyme activity was observed on leaf and root, indicating two sites of nitrate assimilation with a higher activity in the daylight in leaf. The NR activity in leaf was increased after 4h of luminosity. In the root, we observed a high activity during most of the day, especially in periods of higher solar radiation and temperature. To obtain the highest activity of NR in both tissues we suggest 1% n-propanol, 50mM of KNO3- in pH=7 phosphate buffer for 75 min incubation in water bath.

The Determination of Nitrate Reductase Activity of Leaves to the Dominant Species in Forest Community of Northern Aspect of Changbai Mountains

2011 ◽  
Vol 183-185 ◽  
pp. 900-904
Author(s):  
Yu Wen Li ◽  
Yun Jie Wu
Keyword(s):  
Nitrate Reductase ◽  
Tree Species ◽  
Reductase Activity ◽  
Forest Community ◽  
High Yield ◽  
Changbai Mountains ◽  
Ecological Situation ◽  
Nr Activity

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.

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
Keyword(s):  
Nitrate Reductase ◽  
Nitrate Reductase Activity ◽  
Reductase Activity ◽  
Chlorophyll Synthesis ◽  
Growth Retardants ◽  
Chlorophyll Accumulation ◽  
High Concentrations ◽  
Amo 1618 ◽  
Nr Activity

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.

In vivo Nitrate Reductase Activity in Leaves of Pearl Millet, Pennisetum americanum (L.) Leeke

1987 ◽  
Vol 14 (2) ◽  
pp. 125 ◽  
Author(s):  
SV Chanda ◽  
AK Joshi ◽  
PN Krishnan ◽  
YD Singh
Keyword(s):  
Nitrate Reductase ◽  
Reductase Activity ◽  
Potassium Phosphate ◽  
Limiting Factor ◽  
Growth Stages ◽  
In Vivo Assay ◽  
Rate Limiting ◽  
Nr Activity

In the in vivo assay of nitrate reductase (NR) in P. americanum leaves, addition of 1% (v/v) Triton X-100, potassium phosphate buffer (80 mM, pH 7.4) and 1.13 mM NADH to the assay medium resulted in maximum activity. With increasing concentration of NADH, saturation-type kinetics were observed. Based on this data metabolic pool concentration for NADH and apparent Km for nitrate reductase were determined. In field studies with cultivars BJ-104, J-104 and 5141-A of P. americanum, the relative limitation of NO3-, NADH and nitrate reductase in NO3- assimilation was determined. NR activity was measured by four modifications of the in vivo assay technique (with NO3-, with NADH, without NO3- and NADH and with both NO3- and NADH additions to the reaction mixture) and with one in vitro technique. For all the cultivars, NADH was the major rate-limiting factor for in vivo assay during early growth stages, while at later stages, NO3- was limiting. At no stage was NR rate-limiting. It is concluded that NR activity alone may not serve as biochemical marker for improved efficiency of utilisation of nitrogen in P. americanum.

Nitrate Assimilation in Relation to Total Reduced N in Bengal Gram (Cicer arietinum)

1980 ◽  
Vol 16 (2) ◽  
pp. 127-135 ◽  
Author(s):  
T. C. Pokhriyal ◽  
Y. P. Abrol
Keyword(s):  
Nitrate Reductase ◽  
Field Experiment ◽  
Cicer Arietinum ◽  
Nitrate Assimilation ◽  
Seed Filling ◽  
Total Soil ◽  
Bengal Gram ◽  
Nr Activity

SUMMARYOn the basis of a preliminary experiment with 20-day-old Cicer seedlings, wherein the values obtained by integrating the in vivo nitrate reductase (NR) activity with the duration closely approximated the actual reduced N, a field experiment was conducted with cv BG 203 (indeterminate type) to ascertain the extent to which the nitrate assimilated via the enzyme NR contributed to the total reduced N. Soil-derived N accounted for 15.1, 8.3 and 7.2% of the total reduced N at pre-flowering (I), profuse flowering (II) and seed filling (III) stages respectively. Out of the total soil-derived N, 10.1, 59.3 and 30.6% was reduced during stages I, II and III respectively.

scholarly journals Polyaspartic Acid Improves Maize (Zea mays L.) Seedling Nitrogen Assimilation Mainly by Enhancing Nitrate Reductase Activity

Agronomy ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 188 ◽  
Author(s):  
Qingyan Wang ◽  
Huihui Tang ◽  
Guangyan Li ◽  
Hui Dong ◽  
Xuerui Dong ◽  
...  
Keyword(s):  
Zea Mays ◽  
Nitrate Reductase ◽  
Nitrogen Assimilation ◽  
Zea Mays L ◽  
Reductase Activity ◽  
Protein Accumulation ◽  
Nitrogen Accumulation ◽  
Maize Seedlings ◽  
Polyaspartic Acid ◽  
Nr Activity

Improvement of nitrogen use efficiency is of great importance in maize (Zea mays L.) production. In the present study, an eco-friendly growth substance, polyaspartic acid (PASP), was applied to maize seedlings grown with different nitrate (NO3−) doses by foliar spraying, aimed at evaluating its effects on maize nitrogen assimilation at both the physiological and molecular level. The results showed that PASP promoted biomass and nitrogen accumulation in maize seedlings, especially under low NO3− doses. Among different NO3− conditions, the most noticeable increase in plant biomass by PASP addition was observed in seedlings grown with 1 mmol L−1 NO3−, which was a little less than the optimum concentration (2 mmol L−1) for plant growth. Furthermore, the total nitrogen accumulation increased greatly with additions of PASP to plants grown under suboptimal NO3− conditions. The promotion of nitrogen assimilation was mostly due to the increase of nitrate reductase (NR) activities. The NR activities in seedlings grown under low NO3− doses (0.5 and 1.0 mmol L−1) were extremely increased by PASP, while the activities of glutamine synthetase (GS), aspartate aminotransferase (AspAT), and alanine aminotransferase (AlaAT) were slightly changed. Moreover, the regulation of PASP on NR activity was most probably due to the promotion of the protein accumulation rather than gene expression. Accumulation of NR protein was similarly affected as NR activity, which was markedly increased by PASP treatment. In conclusion, the present study provides insights into the promotion by PASP of nitrogen assimilation and identifies candidate regulatory enzymatic mechanisms, which warrant further investigation with the use of PASP in promoting nitrogen utilization in crops.

scholarly journals An Indirect Impact of Sika Deer Overpopulation on Eutrophication of an Aquatic Ecosystem via Understory Vegetation: An Individual-Based Approach Using Nitrate Reductase Activity

2021 ◽  
Vol 9 ◽  
Author(s):  
Yasuo Tsuboike ◽  
Masanori Fujii ◽  
Yumiko Yoshida ◽  
Naoto Kamata
Keyword(s):  
Nitrate Reductase ◽  
Nitrate Reductase Activity ◽  
Sika Deer ◽  
Reductase Activity ◽  
Nitrate Assimilation ◽  
Understory Vegetation ◽  
Vegetation Coverage ◽  
Significant Difference ◽  
The Difference

Eutrophication of aquatic ecosystems is a serious global issue. Stream nitrate concentrations at the University of Tokyo Chichibu Forest have increased since 2000 after the opening of the new highway in 1998. Nitrogen oxide emissions from automobile exhausts were the most likely source of increased nitrate input in the forest ecosystem. Around the area, the sika deer Cervus nippon Temminck population has greatly increased since around 2000 and intensively browsed the understory vegetation. We hypothesized that the degradation of the understory vegetation caused by the deer overpopulation was one of the causes of increased nitrate output. Monthly observations were carried out from April to October 2013 to investigate the understory vegetation at the heights of 0–30 and 100–150 cm above the ground inside (without deer) and outside (with deer) of a deer exclusion fence. Plant taxa and % coverage of each taxon at each layer were recorded. The in vivo nitrate reductase activity (NRA) (≈ nitrate assimilation rate) was determined for each plant taxa each month. Compared to inside the fence, the understory vegetation outside was poor with smaller % coverage and less diverse community structure, and was occupied by unpalatable plant taxa that were uncommon or absent inside the fence. Contrary to our expectation, the phylogenetic diversity of the community assemblage outside the fence showed greater evenness (less clustering) than inside. The NRA peaked in early in the season or late in the season. In contrast to a previous report, no significant difference in the NRA was found between woody and herbaceous plants. Although the difference was no more than that of vegetation coverage, the estimated community-level NRA inside the fence was 5.6 times higher than that of the outside. The difference was greatest early in the season. These results support our hypothesis.

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