The Uptake of Nitrate by<i>Lolium perenne</i>from Flowing Nutrient Solution

Clement, Charles R.; Hopper, M. J.; Jones, L. H. P.

doi:10.1093/jxb/29.2.453

Cited by 175 publications

(85 citation statements)

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“…In contrast, Clement et al (1978) found the mean nitrate uptake rates in natural light in winter to be only about 5% of those found in summer while photon flux density dropped to 10%. In the summer the diurnal change in uptake due to radiation was only a factor of about 3 at most in these experiments.…”

Section: Time Courses Of Net Nitrate Uptake Ratesmentioning

confidence: 71%

“…Rao & Rains (1976b) reported that illumination stimulated nitrate absorption in barley, and Aslam et al (1979) showed that nitrate uptake was 20% faster in the light than in the dark. Clement et al (1978) found that the nitrate uptake in simulated swards of ryegrass was related to diurnal, day-to-day, and seasonal changes in radiation. Delhon et al (1995) recently showed that nitrate influx was down-regulated in the dark.…”

Section: Introductionmentioning

confidence: 96%

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The effects of light on induction, time courses, and kinetic patterns of net nitrate uptake in barley

Peuke

Jeschke

1998

Plant Cell & Environment

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Barley seedlings (Hordeum vulgare L.) were grown hydroponically with (induced) or without (uninduced) nitrate in a light/dark cycle with high photon flux density to determine the effects of light on time courses, induction and kinetics of net nitrate uptake. Nitrate uptake was induced by external nitrate in both light and dark and was prevented by 1 mol m -3 p-fluorophenylalanine. In high light, nitrate uptake was about 2-fold higher than in low light. During time course experiments the uptake rates oscillated due to daily light-dark changes. Rates of nitrate uptake also increased at about 2200 h during continuous darkness. This increase coincided approximately with the time at which the dark period started during the previous culture of the plants, indicating that it was due to a mechanism associated with an endogenous diurnal rhythm. When calculating the kinetics of nitrate uptake, a model with two saturable systems, including a high-affinity system (HATS) and a low-affinity system (LATS), gave the best fit to data in all treatments. The apparent affinity of the HATS ranged from 7·7 to 12·2 mmol m -3 in induced plants in all light conditions. The effect of light on the HATS was mainly an increase of apparent V max in the step from low to high light. In uninduced plants the HATS operated at a very low activity which was strongly enhanced during induction. Interpretation of the calculated kinetics of the LATS was much more difficult on the basis of net uptake data. The apparent affinity of the LATS increased from 24·3 mol m -3 in low light up to 0·17 mol m -3 after acceleration in high light. These extreme changes in apparent affinity of the LATS could not be explained satisfactorily, and the nature of this system is also discussed with respect to the method used.

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Section: Time Courses Of Net Nitrate Uptake Ratesmentioning

confidence: 71%

Section: Introductionmentioning

confidence: 96%

The effects of light on induction, time courses, and kinetic patterns of net nitrate uptake in barley

Peuke

Jeschke

1998

Plant Cell & Environment

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“…In the present experiments the kinetie parameters for N absorption were determined from data colleeted over a period of 2 h. Utider experirnental eonditions, where the plants have aeeess to eonstant external concentrations of NO3" and NH4"^, a steady-state eondition of N uptake rnay be reached whete the growth rate rather than the kinetie N uptake parameters of the plant will determine the N absorption, as detnonsttated by Cletnent et al (1978). However, in a cotnpetitive situation such a steady-state condition of inorganic N absotption is not likely to occur.…”

Section: Kinetic Parameters For N03~ and Nh4^ Absorptionmentioning

confidence: 99%

“…Quantification of the cotnpetitive telations for N tnust be based on a paratnetrization of the telatiotiship between the uptake rates of the tnineral forms (NO3" and NH4"^) and their external concentrations. For this purpose, kinetic paratneters for 'HOf and NH4"û ptake ate required, but are still not well established (see, for exatnple, Schwinning & Patsons 1996), Also, feedback effects linking growth t-ates and internal N status to nitrogen uptake (Cletnent, Hopper & Jones 1978;Larsson et cd. 1992) have to be considered.…”

Section: Introductionmentioning

confidence: 99%

Kinetics of nitrate and ammonium absorption and accompanying H⁺fluxes in roots ofLolium perenneL. and N₂‐fixingTrifolium repensL.

Høgh‐Jensen¹,

Wollenweber²,

Schjøerring³

1997

Plant Cell & Environment

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Kinetie parameters for NH4* and NO," uptake were measured in intact roots of Lolium perenne and actively N2-fixing Trifolium repens. Simultaneously, net H* fluxes between the roots and the root medium were recorded, as were the net photosynthetic rate and transpiration of the leaves. A Michaelis-Menten-type high-afflnity system operated in the concentration range up to about 500 mmol m"' NO," or NH4*. In L. perenne, the V,^,,,, of this system was 9-11 and 13-14 ^mol g"' root FW h"' for NO," and NH4*, respectively. The corresponding values in T, repens were 5-7 and 2 //mol g"' root FW h~'. The K,,, for NH4* uptake was mueh lower in L. perenne than in T, repens

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“…Each culture unit held 200 dmô f recirculating nutrient solution and 24 culture vessels within each of which seedlings were thinned on emergence to give 10 plants. Plants Ca'+, 344; SO^'^, 550; Mg'+, 100; H.^PO,,", 50; Fe'^^, 5-4, with micronutrients as in Clement, et al (1978), and solution pH 6-0 +0-2. Nutrients were replenished manually until day 47.…”

Section: Growth Conditionsmentioning

confidence: 99%

A stay‐green mutation of Lolium perenne affects NO₃⁻ uptake and translocation of N during prolonged N starvation

Barken¹,

Macduff

Humphreys

et al. 1997

New Phytologist

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SUMMARYApparent X,,, and I/,,,,, for net NO.," uptake and short-term translocation patterns of recently absorbed N were compared in a stay-green mutant and wild-type selection line of Lolium pereniie L, by means of a series of depletion studies using ''NO.," , performed over 12 d under conditions of progressively increasing N deprivation. In view of the greater retention of N in senescent leaves of the stay-green phenotype, it was predicted that NO^" uptake would he up-regulated relative to the nomial line, and thiit a proportionally higher fraction of recently absorbed N would be allocated to young leaves. It was shown that the stay-greeit trait had significant phenotypic consequences for plant N relations, with higher 'sink strength' of shoots for recently ahsorhed N, and higher I/,^,f or NO.,-uptake compared with those of normal plants. The stay-green mutation had no effect on the K',,, of the nitrate uptake system. Although the N-use efficiency might he expected to be lower in stay-green than in normal plants, there were no dific-rences in rates of dry matter production.

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The Uptake of Nitrate byLolium perennefrom Flowing Nutrient Solution

Cited by 175 publications

References 0 publications

The effects of light on induction, time courses, and kinetic patterns of net nitrate uptake in barley

The effects of light on induction, time courses, and kinetic patterns of net nitrate uptake in barley

Kinetics of nitrate and ammonium absorption and accompanying H⁺fluxes in roots ofLolium perenneL. and N₂‐fixingTrifolium repensL.

A stay‐green mutation of Lolium perenne affects NO₃⁻ uptake and translocation of N during prolonged N starvation

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The Uptake of Nitrate byLolium perennefrom Flowing Nutrient Solution

Cited by 175 publications

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The effects of light on induction, time courses, and kinetic patterns of net nitrate uptake in barley

The effects of light on induction, time courses, and kinetic patterns of net nitrate uptake in barley

Kinetics of nitrate and ammonium absorption and accompanying H+fluxes in roots ofLolium perenneL. and N2‐fixingTrifolium repensL.

A stay‐green mutation of Lolium perenne affects NO3− uptake and translocation of N during prolonged N starvation

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Kinetics of nitrate and ammonium absorption and accompanying H⁺fluxes in roots ofLolium perenneL. and N₂‐fixingTrifolium repensL.

A stay‐green mutation of Lolium perenne affects NO₃⁻ uptake and translocation of N during prolonged N starvation