Role of xylem sap nitrate in the regulation of nitrate reductase gene expression in leaves of barley (<i>Hordeum vulgare</i>L.) seedlings

Kawachi, Tahei; Shoji, Yoshiro; Sugimoto, Tsuneaki; Oji, Yoshikiyo; Kleinhofs, A.; Warner, Robert L.; Ohtake, Norikuni; Ohyama, Takuji; Sueyoshi, Kuni

doi:10.1080/00380768.2002.10409174

Cited by 16 publications

(14 citation statements)

References 26 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Thus, NH 4 + is released at such a rate that the plant can absorb NH 4 + with little risk of toxicity. Also, in the moisture and oxidizing conditions under which the soil was maintained in this study, NH 4 + was probably slowly oxidized to NO 3 - (Malavolta, 1981), providing a NO 3 -supply just enough to induce a slight NRA increase (Kawachi et al, 2002). When Mo was added, plant development (leaf and stem fresh weight) was partially suppressed, as well as total NRA in leaf tissue.…”

Section: -3mentioning

confidence: 95%

“…There is evidence suggesting that nitrate reductase activity (NRA) is the main limiting step in N assimilation in most plants (Srivastava, 1990;Lea, 1997). Leaf NRA seems to be dependent on the source of N (Roberts & Menary, 1994), and on a continuous supply of nitrate ) through the xylem (Barthes et al, 1996;Kawachi et al, 2002). Molybdenum (Mo) is also important because it is a cofactor of NR (Lea, 1997).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Nitrate reductase activity in leaves and stems of tanner grass (Brachiaria radicans Napper)

Cazetta

Villela

2004

Sci. agric. (Piracicaba, Braz.)

View full text Add to dashboard Cite

Tanner grass (Brachiaria radicans Napper) is a forage plant that is adapted to well-drained soils or wetlands, and responds well to nitrogen (N) fertilization. The assimilation of N involves the nitrate reductase (NR) enzyme, and its activity seems to be dependent on N supply. Molybdenum (Mo) is also important because it is a cofactor of NR. In this study, the variables of an in vivo assay were optimized for measuring nitrate reductase activity (NRA) in the leaves and stem tissues. This method was used to evaluate NO 3 -metabolism in plants fertilized with NaNO 3 , NH 4 Cl or urea, in association with or without application of H 2 MoO 4 , aiming to provide guidelines for N management of this species. The best conditions to determine NRA involved the incubation of 300 mg of tissues in a medium composed of 200 mmol dm -3 phosphate buffer (pH 7.4), 60 mmol dm -3 KNO 3 , 10 cm 3 dm -3 n-butanol, 0.1 cm 3 dm -3 detergent (triton-X-100, under vacuum and in the dark for a period of 60 to 100 minutes. Leaves showed NRA levels two to three times higher than stems. Although there were some interactions between treatments, stem fresh weight and NRA were not affected by N sources. Plants fertilized with NaNO 3 showed the best growth and NRA values when compared with NH 4 Cl and urea, which had, respectively, the lowest and intermediate scores. The application of Mo in the absence of N improved NRA and did not affect leaf and stalk growth. In the presence of N, the Mo levels applied limited leaf NRA and plant development. Key words: Brachiaria arrecta, nitrogen, molybdenum, enzyme ATIVIDADE DA REDUTASE DO NITRATO EM FOLHAS E CAULES DE 'TANNER GRASS'(Brachiaria radicans Napper)RESUMO: A 'tanner grass' (Brachiaria radicans Napper) é uma planta forrageira que se adapta bem tanto em solos bem drenados como em encharcados, e responde bem à adubação nitrogenada. A assimilação do nitrogênio (N) envolve a enzima nitratro redutase (NR) cuja atividade é dependente do suprimento de N. O Molibdênio (Mo) também é importante por ser um co-fator da RN. Neste trabalho foi otimizado um procedimento para a determinação da atividade da redutase do nitrato (NRA) in vivo para tecidos de folha e caule. Este método foi aplicado para avaliar plantas fertilizadas com NaNO 3 , NH 4 Cl ou uréia, com e sem a aplicação de H 2 MoO 4 , visando contribuir no balizamento da adubação nitrogenada para esta espécie. As melhores condições para a determinação da NRA foram: incubação de 300 mg de tecidos em um meio composto por tampão fosfato 200 mmol dm -3 (pH 7,4); KNO 3 60 mmol dm -3; n-butanol 10 cm 3 dm -3; triton-x-100 ® 0,1 cm 3 dm -3; infiltração a vácuo no escuro; por período de 60 a 100 minutos. As folhas apresentaram NRA duas a três vezes maior que os caules. A matéria fresca do caule e a NRA não foi afetada pelas fontes de N. As plantas adubadas com NaNO 3 , NH 4 Cl e uréia apresentaram, respectivamente, os maiores, os menores e intermediários crescimento e NRA. A aplicação de Mo na ausência de N aumentou a NRA e não afetou o crescimento, ma...

show abstract

Section: -3mentioning

confidence: 95%

Section: Introductionmentioning

confidence: 99%

Nitrate reductase activity in leaves and stems of tanner grass (Brachiaria radicans Napper)

Cazetta

Villela

2004

Sci. agric. (Piracicaba, Braz.)

View full text Add to dashboard Cite

show abstract

“…A NR é a enzima mais importante no processo de redução e assimilação de nitrato pelas plantas (PURCINO et al, 1994). A baixa atividade dela é a principal limitação à absorção de N em algumas plantas (LEA et al, 1997), e sua atividade depende principalmente da luz e do contínuo suprimento de nitrato através do xilema (KAWACHI et al, 2002). A GS é importante no processo de incorporação do N, pois catalisa a reação de incorporação do amônio ao glutamato resultando em glutamina (NELSON;COX, 2010).…”

Section: Introductionunclassified

Eficiência na absorção e utilização de nitrogênio e atividade enzimática em genótipos de milho

et al. 2013

View full text Add to dashboard Cite

RESUMO -O objetivo desse estudo foi investigar o emprego dos componentes da eficiência no uso de nitrogênio e das atividades das enzimas nitrato redutase e glutamina sintetase na seleção de genótipos de milho eficientes no uso de nitrogênio (N). Foram avaliados 10 genótipos de milho em estádio de V4 em condições de alto e baixo N. O experimento foi composto por um fatorial 2 x 10 (dois níveis de N e 10 genótipos de milho) em delineamento inteiramente casualizados com três repetições. Os seguintes caracteres foram avaliados: as eficiências na absorção (EAbN), na utilização (EUtN) e no uso de N (EUsN) e as atividades das enzimas glutamina sintetase (GS) e nitrato redutase (NR). Para os caracteres que o efeito de genótipos foi significativo (p 0,05) na análise de variância por nível de N, as médias foram comparadas por meio do teste t (p 0,05). Os ganhos indiretos na EUsN e em seus componentes com seleção sobre as atividades das enzimas NR e GS foram estimados em baixo N. Conclui-se que em alto N: a EAbN é eficiente para discriminar genótipos de milho eficientes no uso de nitrogênio; em baixo N: as EAbN e EUtN são eficientes para discriminar genótipos de milho eficientes no uso de nitrogênio, a atividade de NR não é um bom parâmetro fisiológico para discriminar genótipos de milho eficientes no uso de nitrogênio, e a seleção sobre atividade da enzima GS possibilita a seleção indireta de genótipos de milho eficientes no uso de nitrogênio.Palavras-chave: Absorção. Utilização. Enzima. Melhoramento genético. Seleção indireta.ABSTRACT -The aim of this study was to investigate the employment of components of the nitrogen efficiency use (NUE), and of the activities of the nitrate reductase and glutamine synthetase enzymes in the selection of nitrogen use efficient maize genotypes of maize. Ten maize genotypes at V4 stage were evaluated under high and low N. The experiment consisted of a 2 x 10 factorial (two levels of N and ten maize genotypes), in a randomized complete block design with three replicates. The following traits were evaluated: N uptake efficiency (NUpE), N utilization efficiency (NUtE) and N use efficiency (NUE), and activities of the glutamine synthetase (GS) and nitrate reductase (NR) enzymes. For traits which the effect of genotype was significant (p 0.05) in the variance analysis for level of N, the mean were compared using the t test (p 0.05). The indirect gains in NUE and their components with selection over the activities of the enzymes NR and GS were estimated under low N. We conclude that: under high N, NupE is efficient to differentiate nitrogen use efficient maize genotypes; under low N, NupE and NUtE efficient to differentiate nitrogen use efficient maize genotypes, the activity of NR enzyme is not a good physiological parameter for differentiate nitrogen use efficient maize genotypes, and selection over activity of GS enzyme enables the indirect selection of nitrogen use efficient maize genotypes.

show abstract

“…5). Since the availability of nitrate ions, along with other mechanisms, enhances NR activity, the decreased NR activity observed in Populus × euramericana leaves may be, at least partly, attributed to the depletion of a continuous supply of nitrates through the xylem via the transpiration stream (Kawachi et al 2002). Furthermore, NR can also catalyze the reduction of nitrites to nitric oxide, a cell signaling molecule which plays an important role in plant responses to cadmium stress (Gill et al 2013).…”

Section: Iforest -Biogeosciences and Forestrymentioning

confidence: 99%

Assessment of cadmium tolerance and phytoextraction ability in young Populus deltoides L. and Populus × euramericana plants through morpho-anatomical and physiological responses to growth in cadmium enriched soil

Nikolić¹,

Zorić²,

Cvetković³

et al. 2017

iForest

View full text Add to dashboard Cite

(2)Fast growing woody plants represent effective tools for cadmium (Cd) extraction during remediation of low to medium Cd contaminated soils. Poplars are good candidates for this task because of their rapid growth rate, high biomass yield, and adaptability, as well as the availability of well-characterized clones/ genotypes with various anatomical and physiological traits. The present study evaluates the potential of Populus deltoides (clone B-81) and Populus × euramericana (clone Pannonia) for phytoremediation of Cd contamination in soil. Poplar clones were analyzed for (1) plant growth response to Cd contamination, (2) Cd accumulation, translocation, and partitioning between plant organs, and (3) morphological, anatomical and physiological responses to Cd stress as a function of biomass production. Plants were cultivated in soil moderately contaminated with Cd (8.14 mg kg -1 soil) under semi-controlled conditions for six weeks. Our results suggest that P. × euramericana and P. deltoides clones respond differently to Cd contamination. Biomass production and morphological characteristics were more negatively affected in P. × euramericana than in P. deltoides plants. However, most examined leaf structural parameters were not significantly affected by Cd. In most cases, photosynthetic characteristics and gas exchange parameters were affected by Cd treatment, but the levels and patterns of changes depended on the clone. High tolerance to applied Cd levels, as estimated by the tolerance index, was observed in both clones, but was higher in P. deltoides than P. × euramericana (82.2 vs. 66.5, respectively). We suspect that the higher tolerance to Cd toxicity observed in P. deltoides could be related to unchanged proline content and undisturbed nitrogen metabolism. Following treatment, 58.0 and 46.7% of the total Cd content was accumulated in the roots of P. × euramericana and P. deltoides, respectively, with the remainder in the stems (18.2 and 39.9%) and leaves (23.8 and 13.4%). In summary, P. deltoides displayed better phytoextraction performance under Cd exposure than P. × euramericana, suggesting its potential not only for Cd phytostabilization, but also phytoextraction projects.

show abstract

Role of xylem sap nitrate in the regulation of nitrate reductase gene expression in leaves of barley (Hordeum vulgareL.) seedlings

Cited by 16 publications

References 26 publications

Nitrate reductase activity in leaves and stems of tanner grass (Brachiaria radicans Napper)

Nitrate reductase activity in leaves and stems of tanner grass (Brachiaria radicans Napper)

Eficiência na absorção e utilização de nitrogênio e atividade enzimática em genótipos de milho

Assessment of cadmium tolerance and phytoextraction ability in young Populus deltoides L. and Populus × euramericana plants through morpho-anatomical and physiological responses to growth in cadmium enriched soil

Contact Info

Product

Resources

About