Nitrate Reductase Activity in Soybeans (<i>Glycine max</i> [L.] Merr.)

Nicholas, Joseph C.; Harper, James E.; Hageman, R. H.

doi:10.1104/pp.58.6.731

Cited by 127 publications

(53 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…cv. Calland) were grown as previously described (8). Plants were grown in environmental chambers under 14-hr light and 10-hr dark periods at 30 and 20 C, respectively.…”

Section: Methodsmentioning

confidence: 99%

“…In vivo NR activity was determined as previously described (8). In vitro NR activity was assayed as described by Scholl et al (9), with the exception that the crude (uncentrifuged) extract was assayed.…”

Section: Methodsmentioning

confidence: 99%

“…The current study was initiated to determine the effect of the addition of various glycolytic or Krebs cycle intermediates to the in vivo NR assay medium on measurable NR activity of soybean leaves harvested from plants pretreated with different temperature, light, and dark regimes reported previously (8).…”

mentioning

confidence: 99%

See 2 more Smart Citations

Nitrate Reductase Activity in Soybeans (Glycine max [L.] Merr.)

Nicholas¹,

Harper²,

Hageman³

1976

Plant Physiol.

Self Cite

View full text Add to dashboard Cite

Growth chamber studies with soybeans (Glycine max [L.] Mef.) were designed to determine the relative limitations of NO3-, NADH, and nitrate reductase (NR) per se on nitrate metabolism as affected by light and temperature. Three NR enzyme assays (+NO3-in vivo, -NO3-in vivo, and in vitro) were compared. NR activity decreased with al assays when plants were exposed to dark. Addition of NO3-to the in vivo NR assay medium increased activity (over that of the -NO3-in vivo assay) at aUl sampUng periods of a normal day-night sequence (14 hr-30 C day; 10 hr-20 C night), indicating that NO3-was rate-limiting. The stimulation of In vivo NR activity by NO3-was not seen in plants exposed to extended dark periods at elevated temperatures (16 hr-30 C), indicating that under those conditions, NO3-was not the limiting factor. Under the latter condition, in vitro NR activity was appreciable (19 ,umol NO2-[g fresh weight, hr]-1) suggesting that enzyme level per se was not the limiting factor and that reductant energy might be limiting.The addition of NADH to the in vivo NR assay medium did not stimulate NR activity, although it was not established that NADH entered the tissue. The addition of glucose, fructose 1,6-diphosphate, pyruvate, citrate, succinate, or malate to the in vivo assay medium significantly increased measurable NR activity of leaf tissue from plants pretreated to extended dark periods at elevated temperature. Glucose additions were most effective, usually stimulating increases 2-to 3-fold greater than the other metabolites. Increased NR activities from the various additives were attributed to production of NADH. The loss of in vivo NR activity in soybeans during darkness appeared to be due to the combination of a net loss of enzyme per se and energy depletion. The subsequent light stimulation of NR activity was likely due to increased availability of reductant energy as well as a net synthesis of the NR enzyme.Since the original characterization of reductant energy requirements of NR2 (3), many investigators have reported on the capacity of various plant species to utilize NADH as the preferred electron donor for NR (1, 2, 5). Klepper et al. (5) concluded that sugars which migrated from the chloroplasts were the primary source of energy, and that the oxidation of glyceraldehyde 3-P was the in situ source of NADH for nitrate reduction in corn. Malate has also been implicated as an energy source for NADH generation in corn (7). Tingey (10) reported that addition of 48 mm glucose to the incubation medium significantly I Cooperative investigation of the North Central Region, Agricultural

show abstract

“…cv. Calland) were grown as previously described (8). Plants were grown in environmental chambers under 14-hr light and 10-hr dark periods at 30 and 20 C, respectively.…”

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Nitrate Reductase Activity in Soybeans (Glycine max [L.] Merr.)

Nicholas¹,

Harper²,

Hageman³

1976

Plant Physiol.

Self Cite

View full text Add to dashboard Cite

show abstract

“…In vivo nitrate reductase activity was assayed in leaves and roots (Nicholas et al, 1976). Leaf discs or roots (sections 2-3 cm in length) were vacuum infiltrated with a medium containing 100 mM Kphosphate buffer (pH 7.5), 5% propanol (v\v) and 50 mM KNO $ and incubated at 30mC for 30 and 60 min.…”

Section: Methodsmentioning

confidence: 99%

Nitrogen and phosphorus availability limit N₂ fixation in bean

Leidi

Rodríguez-Navarro

2000

New Phytologist

View full text Add to dashboard Cite

Availability of nitrogen (N) and phosphorus (P) might significantly affect N # fixation in legumes. The interaction of N and P was studied in common bean (Phaseolus vulgaris), considering their effects on nodulation and N # fixation, nitrate reductase activity, and the composition of N compounds in xylem sap. The effect of N on the uptake of P by plants was estimated by analysing rhizospheric pH and P concentration in xylem sap and in plant shoots. Inoculated bean plants were grown in pots containing perlite\vermiculite in two experiments with different amounts of P and N. In a third experiment, bean plants were grown on two soil types or on river sand supplied with different concentrations of N. At harvest, shoot growth, number of nodules and mass, and nitrogenase activity were determined. Xylem sap was collected for the determination of ureides, amino acids, nitrate and phosphate concentration. At low nitrate concentration (1 mM), increasing amounts of P promoted both nodule formation and N # fixation, measured as ureide content in the xylem sap. However, at high nitrate concentration (10 mM), nodulation and N # fixation did not improve with increased P supply. Glutamine and aspartate were the main organic N compounds transported in the xylem sap of plants grown in low nitrate, whereas asparagine was the dominant N compound in xylem sap from plants grown in high nitrate. Nitrate reductase activity in roots was higher than in shoots of plants grown with low P and high N. In both soils and in the sand experiment, increased application of N decreased nodule mass and number, nitrogenase activity and xylem ureides but increased the concentration of asparagine in xylem sap. Increasing P nutrition improved symbiotic N # fixation in bean only at low N concentrations. It did not alleviate the inhibitory effect of high nitrate concentration on N # fixation. A decrease in plant P uptake was observed, as indicated by a lower concentration of P in the xylem sap and shoots, correlating with the amount of N supplied. Simultaneously with the specific inhibition of N # fixation, high nitrate concentrations might decrease P availability, thus inhibiting even further the symbiotic association because of the high P requirement for nodulation and N # fixation.

show abstract

“…In vivo NR activity was assayed using the leaf disc method of Nicholas et al (1976). Weighed leaf punches (approximately 200 mg) were vacuum infiltrated in 10 mL of incubation buffer (0.1 m potassium phosphate [pH 7.5], 0.05 m KNO 3 , 1% [v/v] propanol).…”

Section: Nr Assaymentioning

confidence: 99%

Chilling Delays Circadian Pattern of Sucrose Phosphate Synthase and Nitrate Reductase Activity in Tomato1

Jones¹,

Tucker²,

Ort

1998

Plant Physiology

View full text Add to dashboard Cite

Overnight low-temperature exposure inhibits photosynthesis in chilling-sensitive species such as tomato (Lycopersicon esculentum) and cucumber by as much as 60%. In an earlier study we showed that one intriguing effect of low temperature on chilling-sensitive plants is to stall the endogenous rhythm controlling transcription of certain nuclear-encoded genes, causing the synthesis of the corresponding transcripts and proteins to be mistimed when the plant is rewarmed. Here we show that the circadian rhythm controlling the activity of sucrose phosphate synthase (SPS) and nitrate reductase (NR), key control points of carbon and nitrogen metabolism in plant cells, is delayed in tomato by chilling treatments. Using specific protein kinase and phosphatase inhibitors, we further demonstrate that the chilling-induced delay in the circadian control of SPS and NR activity is associated with the activity of critical protein phosphatases. The sensitivity of the pattern of SPS activity to specific inhibitors of transcription and translation indicates that there is a chilling-induced delay in SPS phosphorylation status that is caused by an effect of low temperature on the expression of a gene coding for a phosphoprotein phosphatase, perhaps the SPS phosphatase. In contrast, the chilling-induced delay in NR activity does not appear to arise from effects on NR phosphorylation status, but rather from direct effects on NR expression. It is likely that the mistiming in the regulation of SPS and NR, and perhaps other key metabolic enzymes under circadian regulation, underlies the chilling sensitivity of photosynthesis in these plant species.Most warm-climate plant species are sensitive to brief exposures to low, nonfreezing temperatures. Lowtemperature exposure in combination with high irradiance causes rapid, often very severe inhibition of photosynthesis in a broad range of plants, including maize (Baker et al., 1983), cucumber (Peeler and Naylor, 1988), and tomato (Lycopersicon esculentum) (Martin and Ort, 1985). Several elements that contribute to this inhibition have been identified and all may ultimately arise from the photosynthetic production of oxygen radicals (Wise, 1995). An inhibition of electron-transport capacity originating from damage to the reducing side of PSII is well documented (e.g. Powles et al., 1983;Kee et al., 1986; Percival et al., 1987) and, for moderately sensitive species such as maize, may be the major cause of impaired whole-plant photosynthesis after chilling. However, in the most severely chilling-sensitive species, such as domestic tomato, impaired reductive activation of the stromal bisphosphatases appears to be the dominating factor limiting carbon assimilation after chilling in the light (Sassenrath et al., 1990).Low temperature at night can also cause severe reductions in CO 2 fixation that persist on the day after the chill, even after optimal growth temperatures have been restored. Like the inhibition caused by chilling in the light, it is clear that the primary loss of activity is caused b...

show abstract

Nitrate Reductase Activity in Soybeans (Glycine max [L.] Merr.)

Cited by 127 publications

References 20 publications

Nitrate Reductase Activity in Soybeans (Glycine max [L.] Merr.)

Nitrate Reductase Activity in Soybeans (Glycine max [L.] Merr.)

Nitrogen and phosphorus availability limit N₂ fixation in bean

Chilling Delays Circadian Pattern of Sucrose Phosphate Synthase and Nitrate Reductase Activity in Tomato1

Contact Info

Product

Resources

About

Nitrate Reductase Activity in Soybeans (Glycine max [L.] Merr.)

Cited by 127 publications

References 20 publications

Nitrate Reductase Activity in Soybeans (Glycine max [L.] Merr.)

Nitrate Reductase Activity in Soybeans (Glycine max [L.] Merr.)

Nitrogen and phosphorus availability limit N2 fixation in bean

Chilling Delays Circadian Pattern of Sucrose Phosphate Synthase and Nitrate Reductase Activity in Tomato1

Contact Info

Product

Resources

About

Nitrogen and phosphorus availability limit N₂ fixation in bean