Consulta: subjectFacets:"Nitrate reductase"
Registros recuperados: 19
Data/hora: 03/06/2024 07:42:19

Influence of metal ions and organic carbons on denitrification activity of the halotolerant bacterium, Paracoccus pantotrophus P16 a strain from shrimp pond
Provedor de dados: 69
Autores: Pintathong,Punyawatt; Richardson,David J; Spiro,Stephen; Choorit,Wanna.
The effect of metal ions, ferric ion (Fe3+) and molybdenum ion (Mo6+) on the denitrification process of Paracoccus pantotrophus P16 grown under saline conditions was investigated. Results revealed that the dosages of added Fe3+ and Mo6+ significantly accelerated nitrate utilization and nitrite accumulation. Enzymatic studies revealed that the membrane-bound nitrate reductase and the periplasmic nitrite reductase had activities of 998 ± 28 and 373 ± 18 nmol (mg protein)-1 min-1, respectively after growing Paracoccus pantotrophus P16 in medium supplemented with 1.5 µM Fe3+. If provided with 1.5 µM Fe3+and 2.4 µM Mo6+, the membrane-bound nitrate reductase activity increased to 6,223 ± 502 nmol (mg protein)-1 min-1 and the periplasmic nitrite reductase was 344...
Tipo: Journal article
Palavras-chave: Metal ions; Nitrate reductase; Nitrite accumulation; Nitrite reductase; Paracoccus pantotrophus.
Ano: 2009
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582009000200004

Characterization of nitrate reductase activity in vitro in Gracilaria caudata J. Agardh (Rhodophyta, Gracilariales)
Provedor de dados: 88
Autores: Chow,Fungyi; Capociama,Fernanda V.; Faria,Renata; Oliveira,Mariana C. de.
The marine red alga Gracilaria caudata J. Agardh has been used in Brazil for agar extraction, mainly in the northeast region of the country. Nitrogen availability is the most important abiotic factor in seawater that limits the growth of seaweeds. The enzyme nitrate reductase (NR) is the key regulatory point in the nitrogen assimilation in photosynthetic organisms. This study describes an in vitro assay, characterizing the enzymatic activity of NR in terms of kinetic constants and stability, its oscillation during the day and glucose effect on NR modulation. Maximal peaks of NR activity were recorded at 20 ºC and pH 8.0. The enzymatic stability in crude extracts stored at 3 ± 1 ºC decreased significantly after 48 hours. Apparent Michaelis-Menten constants...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Agarophyte; Gracilaria caudata; Nitrate reductase; Nitrogen metabolism.
Ano: 2007
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-84042007000100012

Estudo da eficiência de uso do nitrogênio em variedades locais e melhoradas de milho
Provedor de dados: 88
Autores: MAJEROWICZ,NIDIA; PEREIRA,JOSÉ M.S.; MEDICI,LEONARDO O.; BISON,ODAIR; PEREIRA,MAURÍCIO B.; SANTOS JÚNIOR,ULYSSES M.
O uso de fertilizantes, além dos riscos de contaminação ambiental, onera o agricultor, chegando a representar 40% dos custos de produção na cultura do milho. O presente estudo visa identificar características fisiológicas relacionadas com o aumento da eficiência do uso do nitrogênio e assim subsidiar programas de melhoramento genético direcionados para obtenção de genótipos de milho produtivos em solos com baixa disponibilidade de nitrogênio. Foram estudadas as variedades de milho Pedra Dourada, Catetão, Carioca (variedades locais, não melhoradas), BR 106, BR 105 (variedades melhoradas em solos férteis), Nitroflint e Nitrodente (variedades melhoradas em solos pobres em N). Plântulas de milho receberam solução nutritiva de Hoagland modificada quanto às...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Nitrogen assimilation; Glutamine synthetase; Nitrate reductase; Photosynthetic pigments; Zea mays L.
Ano: 2002
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-84042002000200002

Variações diurnas da atividade in vivo da redutase do nitrato em abacaxizeiro (Ananas comosus (L.) Merr. - Bromeliaceae)
Provedor de dados: 88
Autores: NIEVOLA,CATARINA CARVALHO; MERCIER,HELENICE.
A análise da atividade enzimática da redutase do nitrato baseou-se no método do ensaio in vivo, que foi padronizado para os tecidos foliares e radiculares do abacaxizeiro cultivado in vitro. As maiores atividades enzimáticas foram obtidas quando se empregou como meio de reação uma solução tampão fosfato 0,1 M, contendo KNO3 100 mM e 3% de n-propanol, a faixa de pH ótimo foi de 6,5 a 7,5. O tempo de incubação foi de 60 min a 30 °C. Essa padronização mostrou-se muito importante para a análise do ritmo diurno da redutase do nitrato em abacaxizeiro, visto que as condições de ensaio in vivo dessa enzima variam muito entre diferentes espécies vegetais. As folhas apresentaram as maiores atividades na presença de luz. As raízes mostraram atividade da redutase do...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Nitrate reductase; Pineapple; Diurnal rhythm; Bromeliad; Bromeliaceae.
Ano: 2001
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-84042001000300008

Enzyme activities of phytoplankton in the South Shetland Islands (Antarctica) in relation to nutrients and primary production
Provedor de dados: 97
Autores: IRIARTE,JOSÉ L; GONZÁLEZ,RODRIGO R; QUIÑONES,RENATO A; KANG,SUNG-HO; SHIM,JAE H; VALENZUELA,CYNTHIA P.
Given the potential significance of enzyme activities as a link between internal metabolic pathways and environmental nutrients, we investigated the relationships of nitrate reductase (NR) and alkaline phosphatase (AP) with primary production and inorganic nutrients in South Shetland Islands, Antarctica. Enzymatic activities of the phytoplankton (0.7-210 µm), primary productivity, autotrophic biomass and inorganic nutrients were studied in the upper 100 m depth at nine stations during a cruise in the northwestern area of South Shetland Islands (Antarctica), during late austral spring (December 2000). NR activities fluctuated between 0 and 42.8 nmol L-1 h-1 (mean = 10.08 nmol L-1 h-1, SD = 10.42 nmol L-1 h-1), AP activities between 0.81 and 5.67 nmol L-1...
Tipo: Journal article
Palavras-chave: Nitrate reductase; Alkaline phosphatase; Primary productivity; Chlorophyll; Antarctica.
Ano: 2006
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-078X2006000400009

Effects of solar UV radiation on photosynthesis and enzyme activities (carbonic anhydrase and nitrate reductase) in marine macroalgae from southern Spain
Provedor de dados: 97
Autores: FIGUEROA,FÉLIX L.; VIÑEGLA,BENJAMÍN.
The effects of solar ultraviolet (UV) radiation during daily cycles on photosynthesis and two key enzymes involved in carbon incorporation, the carbonic anhydrase, and in inorganic nitrogen reduction, the nitrate reductase, of macroalgae from southern Spain are presented. During daily cycles, photoinhibition in several intertidal macroalgae, expressed as decrease in the effective quantum yield from the morning to noon time, was linearly dependent on the daily integrated irradiance. However, recovery, expressed as the increase in the effective quantum yield from noon to the afternoon, presented a different pattern; full recovery was found below daily integrated irradiance of 1.0 x10(4) kJ m-2. However, recovery reached only 50 % at higher irradiances. The...
Tipo: Journal article
Palavras-chave: Carbonic anhydrase; Chlorophyll fluorescence; Effective quantum yield; Nitrate reductase; Ultraviolet radiation.
Ano: 2001
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-078X2001000200003

Agronomic studies of corn and sorghum during 1977
Provedor de dados: 106
Autores: Supot Faungfupong; Wasana Wongyai; Kittima Montranon; Surapol Chowchong.
12 tables
Palavras-chave: Corn; Maize; Sorghum; Growth; Nitrate reductase; Agronomic characters; Dry weight; Nitrogen fertilizers; Weed control; Yields; ข้าวโพด; ข้าวฟ่าง; การเจริญเติบโต; การแข่งขันกับวัชพืช.
Ano: 1977
URL: http://anchan.lib.ku.ac.th/agnet/handle/001/3921

Cultural practice studies in corn and sorghum during 1976
Provedor de dados: 106
Autores: Supot Faungfupong; Wasana Wongyai; Kittima Montranon; Surapol Chowchong.
17 tables
Palavras-chave: Corn; Maize; Sorghum; Variety trials; Direction of planting; Nitrogen fertilizers; Nitrate reductase; Plant population; Tannin; Yields; ข้าวโพด; ข้าวฟ่าง; ประชากรพืช; แทนนิน; ปริมาณ; เอนไซม์; ไนเตรตรีดัคเตส; ทิศทางการปลูก; การเพาะปลูก.
Ano: 1976
URL: http://anchan.lib.ku.ac.th/agnet/handle/001/3853

Foliar application of 28-homobrassinolide mitigates salinity stress by increasing the efficiency of photosynthesis in Brassica juncea
Provedor de dados: 39
Autores: Alyemeni,Mohammed Nasser; Hayat,Shamsul; Wijaya,Leonard; Anaji,Abdullah.
Prior to sowing, seeds of Brassica juncea Czern and Coss cv. Varuna were soaked in water (controls) or in 50, 100 or 150 mM of sodium chloride (NaCl) for 6 h. The resulting plants, at 15, 30 and 45 days after sowing (DAS) were either not treated (controls) or were treated with aqueous solutions of the hormone 28-homobrassinolide (HBL), which was applied to their foliage in concentrations of 10-10, 10-8 or 10-6 M. The concentration of NaCl showed an inverse correlation with the activity of nitrate reductase (EC 1.6.6.1), the activity of carbonic anhydrase (EC 4.2.1.1), chlorophyll content at 60 DAS, the rate of photosynthesis at 60 DAS, and seed yield at 140 DAS (at harvest), all of which decreased in parallel with increases in NaCl concentration. However,...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Carbonic anhydrase; Chlorophyll; Homobrassinolide; Nitrate reductase; Seed yield.
Ano: 2013
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0102-33062013000300007

Development of a transformation system for Penicillium brevicompactum based on the Fusarium oxysporum nitrate reductase gene
Provedor de dados: 58
Autores: Varavallo,Maurílio Antônio; Queiroz,Marisa Vieira de; Pereira,Jorge Fernando; Ribeiro,Ronney Adriano; Soares,Marcos Antônio; Ribeiro,João Batista; Araújo,Elza Fernandes de.
Penicillium brevicompactum is a filamentous fungus that presents a potential for industrial use due its efficient pectinase production. A heterologous transformation system was developed for P. brevicompactum based on the complementation of a nitrate reductase mutant. Nitrate reductase mutants were obtained by resistance to chlorate in a rate of 23.24% when compared to other mutations that lead to the chlorate resistance. One mutant named 4457-18X was chosen for the transformation experiments with the pNH24 vector containing de Fusarium oxysporum nitrate reductase gene. A frequency of approximately 3 transformants/µg DNA was obtained using the circular vector pNH24. This frequency was multiplied about 10 fold using the linearized vector with the Xba I...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Nitrate reductase; Penicillium brevicompactum; Heterologous transformation.
Ano: 2005
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822005000200015

DROUGHT-INDUCED EFFECTS AND RECOVERY OF NITRATE ASSIMILATION AND NODULE ACTIVITY IN COWPEA PLANTS INOCULATED WITH BRADYRHIZOBIUM SPP. UNDER MODERATE NITRATE LEVEL
Provedor de dados: 58
Autores: Silveira,Joaquim Albenísio Gomes da; Costa,Roberto Cezar Lobo da; Oliveira,José Tadeu Abreu.
This study was carried out to establish comparative effects of drought and recovery on the nitrate assimilation and nodule activity related to N2 fixation in cowpea plants [Vigna unguiculata L. (Walp.)] previously inoculated with Bradyrhizobium spp. BR-3256 (CB-756) strain in the presence of 5 mol m-3 NO-3. Twenty-eight-day-old nodulated plants were submitted to water deprivation during 4 consecutive days and afterwards resupplied with nutrient solution during 2 days. The water deprivation caused a rapid increase in the nitrate content in root and a marked reduction in leaf nitrate reductase (NR) activity. In contrast nodule NR activity was slightly increased by water deprivation. Concomitantly, in nodules of water stressed plants, leghemoglobin and...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Glutamine synthetase; Leghemoglobin; Nitrate reductase; N2 fixation; Water stress; Vigna unguiculata (L.) Walp.
Ano: 2001
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822001000300005

Fast detection of Mycobacterium tuberculosis in culture-positive sputum samples by nitrate reductase activity
Provedor de dados: 60
Autores: Meneguello,Jean Eduardo; Silva,João Vitor de Oliveira; Lima,Letícia Silva; Siqueira,Vera Lucia Dias; Scodro,Regiane Bertin de Lima; Caleffi-Ferracioli,Katiany Rizzieri; Cardoso,Rosilene Fressatti.
ABSTRACT Microscopy and bacterial culture are the main tools in the diagnosis of tuberculosis. Since the slow growth of Mycobacterium tuberculosis impairs rapid diagnosis strategies, especially in countries where the latter are the only available resources, the ongoing development of new and inexpensive tools based on mycobacterial metabolism optimizing growth detection with preliminary identification is greatly welcome. When compared to the other species from the M. tuberculosis complex, M. tuberculosis is a strong nitrate reducer. Current assay compares the nitrate reductase activity of M. tuberculosis from pulmonary specimens cultivated in nitrate-supplemented media. Fifty-five sputum samples were decontaminated and inoculated in conventional...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Tuberculosis; Mycobacteria/diagnosis/identification; Nitrate reductase.
Ano: 2018
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1984-82502018000100602

The effects of salt stress on growth, nitrate reduction and proline and glycinebetaine accumulation in Prosopis alba
Provedor de dados: 61
Autores: Meloni,Diego Ariel; Gulotta,Marta Rosalía; Martínez,Carlos Alberto; Oliva,Marco Antonio.
Prosopis alba (algarrobo) is one of the most important salt-tolerant legumes used in the food and furniture industries. The effects of salinity on some growth and physiological parameters in algarrrobo seedlings were investigated. 17-Day-old seedlings were subjected to three salt treatments by adding NaCl to the growth medium in 50 mmol.L-1 increments every 24 h until the final concentrations of 0, 300 and 600 mmol.L-1 were reached. Only the highest NaCl concentration affected all of the considered parameters. Thus, 600 mmol.L-1 NaCl caused a significant reduction in root and shoot growth, but an increase in the root/shoot ratio. Leaf relative water content, nitrate content and nitrate reductase activity in leaves and roots were also decreased. At 300 and...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Glycinebetaine; Nitrate reductase; Proline; Salinity.
Ano: 2004
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202004000100006

Changes in nitrate reductase activity and oxidative stress response in the moss Polytrichum commune subjected to chromium, copper and zinc phytotoxicity
Provedor de dados: 61
Autores: Panda,Sanjib Kumar; Choudhury,Shuvasish.
The main aim of this paper was to investigate the effect of chromium (Cr), copper (Cu) and zinc (Zn) on nitrate reductase (NR) activity and oxidative stress responses in the moss Polytrichum commune. Cr, Cu and Zn resulted in the inhibition of NR activity. A decline in total chlorophyll content was observed after 24 and 48 h of metal treatment. Accumulation of the metals showed a dose and time dependent increase. High accumulation of Cu, Cr and Zn were seen in moss shoots after 24 and 48 h of treatment. Treatment of Cr, Cu and Zn for 24 or 48 h resulted in the increase of malondialdehyde (MDA) content in moss shoots. The highest increase was observed in shoots under Cu treatment followed by Cr and Zn. The MDA content was significantly higher after 48h....
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Antioxidants; Chromium; Copper; Malondialdehyde; Nitrate reductase; Oxidative stress; Polytrichum commune; Zinc.
Ano: 2005
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202005000200001

Nitrate uptake and metabolism by roots of soybean plants under oxygen deficiency.
Provedor de dados: 61
Autores: Brandão,Andrea D.; Sodek,Ladaslav.
Nitrate is reported to improve tolerance of plants towards oxygen deficiency enabled by waterlogging of the root system, but the mechanism underlying the phenomenon remains poorly understood. We studied the metabolism of nitrate in roots exposed to hypoxia, using soybean plants growing in a hydroponic system after suspending aeration and covering the surface of the nutrient solution with mineral oil. Nitrate depletion from the medium was more intense under hypoxia than normoxia, but in the presence of chloramphenicol, consumption under hypoxia was significantly reduced. Nitrite accumulated in the medium in the state of hypoxia and this effect was partially eliminated by chloramphenicol. Nitrate consumption sensitive to chloramphenicol was attributed to...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Glycine max; Hypoxia; Nitrate reductase; Nitrite; Waterlogging.
Ano: 2009
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202009000100003

Aspects of nitrogen metabolism in coffee plants
Provedor de dados: 61
Autores: Carelli,Maria Luiza Carvalho; Fahl,Joel Irineu; Ramalho,José D. Cochicho.
Coffee plants are highly N-demanding plants. Despite the importance of N nutrition for the development, acclimation and yield of coffee plants, there are few reports concerning N metabolism in this species. In this review, our intention is to summarize the information available in the literature and to point out the influence of environmental conditions on N assimilation, as well as comment and discuss some apparently contradictory results and raise and enlighten queries about N assimilation in coffee plants.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Coffea; Irradiance level; Nitrate reductase; Nitrogen fertilization; Oxidative stress; Photoinhbition; Photoprotection; Photosynthesis.
Ano: 2006
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202006000100002

Activation of nitrate reductase of cashew leaf by exogenous nitrite
Provedor de dados: 61
Autores: Viégas,Ricardo Almeida; Silveira,Joaquim Albenísio Gomes.
Nitrate reductase (NR) plays a central role in plant primary metabolism and exhibits complex regulation mechanisms for its catalytic activity. There is controversy in the literature concerning the possible direct effect of NO2- on the stimulation and/or activation of NR activity. The influence of NO2- was studied on the NR activity in the leaves of 30-day-old cashew (Anacardium occidentale L.) seedlings. Addition of NO2- to the reaction mixture containing leaf enzymatic extract resulted in a remarkable increase in NR activity. A trace amount (5 mumol.L-1) of NO2- was required to achieve full NR activity. The in vitro NR-activity showed a steady time-dependent increase when incubated in the presence of only NO3- + NO2-. In contrast, in vitro NR activity was...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Anacardium occidentale; Enzymes; NADH; Nitrate metabolism; Nitrate reductase.
Ano: 2002
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202002000100005

Establishment of sensitive and resistant variety of tomato on the basis of photosynthesis and antioxidative enzymes in the presence of cobalt applied as shotgun approach
Provedor de dados: 61
Autores: Hasan,Syed Aiman; Hayat,Shamsul; Wani,Arif Shafi; Ahmad,Aqil.
Cobalt (Co) affords both beneficial as well as toxic effects to plants. The present study was performed with an aim to find out the varietal differences among five tomato cultivars against the Co induced changes in growth, photosynthesis, nitrate reductase (E.C.1.6.6.1), carbonic anhydrase (E.C.4.2.1.1), antioxidative enzymes i.e. peroxidase (E.C.1.11.1.7), catalase (E.C.1.11.1.6), superoxide dismutase (E.C.1.15.1.1) and that of proline content. Seeds of tomato (varieties, K-25, NTS-9, NBR-Uday, Sarvodya, and Malti) were soaked in 0, 100, 200 or 300 µM CoCl2 for 0, 4, 8, 12 h (shotgun approach) and sampled at 30 days after sowing. All the varieties showed significantly different response to different treatment combinations. Despite substantial varietal...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Antioxidative enzyme; Carbonic anhydrase; Cobalt; Nitrate reductase; Photosynthesis; Tomato.
Ano: 2011
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202011000300001

Anatomic and physiological modifications in seedlings of Coffea arabica cultivar Siriema under drought conditions
Provedor de dados: 64
Autores: Melo,Emanuelle Ferreira; Fernandes-Brum,Christiane Noronha; Pereira,Fabrício José; Castro,Evaristo Mauro de; Chalfun-Júnior,Antonio.
Due to the weather changes prognostic for the coming years, the understanding of water deficit and physiological responses of plants to drought becomes an important requirement in order to develop technologies such as mechanisms to assist plants to cope with longer drought periods, which will be essential to maintenance of Brazilian and worldwide production. This study aimed to evaluate ecophysiological and anatomical aspects as well as the nitrate reductase activity in Siriema coffee seedlings subjected to four treatments: Daily irrigated, non-irrigated, re-irrigated 24 hours and re-irrigated 48 hours after different stress periods. Non-irrigation promoted a reduction in leaf water potential being accented from the ninth day of evaluation onwards....
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Coffee tree; Ecophysiology; Water stress; Nitrate reductase.
Ano: 2014
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1413-70542014000100003