Studies of the Uptake of Nitrate in Barley

Siddiqi, M. Yaeesh; Glass, Anthony D. M.; Ruth, Thomas J.; Rufty, Thomas W.

doi:10.1104/pp.93.4.1426

Cited by 382 publications

(451 citation statements)

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“…The HATS is involved in nitrate uptake at low external nitrate concentrations (as low as 1 lM) while the LATS operates at higher concentration ([0.5 mM) (see review by Nacry et al 2013). Both systems possess a constitutive component (cHATS; cLATS) and an inducible component (iHATS; iLATS) (Siddiqi et al 1989(Siddiqi et al , 1990Faure-Rabasse et al 2002). Among the nine LjNPF genes studied in L. japonicus, expression of only CM0608.1210 was induced by nitrate.…”

Section: Function Of Nitrate Transport In Legumes Role Of Transportermentioning

confidence: 99%

Nitrate transporters: an overview in legumes

Pellizzaro

Alibert

Planchet

et al. 2017

Planta

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Main conclusion The nitrate transporters, belonging to NPF and NRT2 families, play critical roles in nitrate signaling, root growth and nodule development in legumes.Nitrate plays an essential role during plant development as nutrient and also as signal molecule, in both cases working via the activity of nitrate transporters. To date, few studies on NRT2 or NPF nitrate transporters in legumes have been reported, and most of those concern Lotus japonicus and Medicago truncatula. A molecular characterization led to the identification of 4 putative LjNRT2 and 37 putative LjNPF gene sequences in L. japonicus. In M. truncatula, the NRT2 family is composed of 3 putative members. Using the new genome annotation of M. truncatula (Mt4.0), we identified, for this review, 97 putative MtNPF sequences, including 32 new sequences relative to previous studies. Functional characterization has been published for only two MtNPF genes, encoding nitrate transporters of M. truncatula. Both transporters have a role in root system development via abscisic acid signaling: MtNPF6.8 acts as a nitrate sensor during the cell elongation of the primary root, while MtNPF1.7 contributes to the cellular organization of the root tip and nodule formation. An in silico expression study of MtNPF genes confirmed that NPF genes are expressed in nodules, as previously shown for L. japonicus, suggesting a role for the corresponding proteins in nitrate transport, or signal perception in nodules. This review summarizes our knowledge of legume nitrate transporters and discusses new roles for these proteins based on recent discoveries.

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Section: Function Of Nitrate Transport In Legumes Role Of Transportermentioning

confidence: 99%

Nitrate transporters: an overview in legumes

Pellizzaro

Alibert

Planchet

et al. 2017

Planta

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“…The HATS is described as a saturable system, whereas the nature of the LATS is still not clear. Doddema & Telkamp (1979) and Goyal & Huffaker (1986b) found a second saturable system, but Siddiqi et al (1990) and Aslam, Travis & Huffaker (1992) observed a linear non-saturable component under higher concentrations of nitrate. Aslam et al (1992) even found two saturable, possibly constitutive systems in the low concentration range and a linear system at more than 500 mmol m -3 nitrate.…”

Section: Introductionmentioning

confidence: 99%

“…Aslam et al (1992) even found two saturable, possibly constitutive systems in the low concentration range and a linear system at more than 500 mmol m -3 nitrate. Despite some evidence that the LATS is of a passive nature Siddiqi et al 1991), it appears more likely that HATS and LATS both proceed thermodynamically uphill (King, Siddiqi & Glass 1992). In the papers mentioned above, two methods were used for exploring the kinetics: the first monitoring the depletion of nitrate from the external medium and the second following the movement of tracers (for a review, see Peuke & Kaiser 1996).…”

Section: Introductionmentioning

confidence: 99%

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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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“…Based on Siddiqi et al (1989Siddiqi et al ( , 1990, we also introduced a negative feedback of root nitrate concentration on the parameters related to HATS and LATS functions (eqn 5). The rate of nitrate net uptake (eqn 6) is calculated from the nitrate influx weighted by a parameter accounting for nitrate efflux [r influx:net uptake , estimated from Devienne et al (1994)] and root carbohydrate concentration (eqn 7).…”

Section: Nitrate Uptake By Roots and Concentration In Soilmentioning

confidence: 99%

CN-Wheat, a functional–structural model of carbon and nitrogen metabolism in wheat culms after anthesis. I. Model description

Barillot

Chambon

Andrieu

2016

Ann Bot

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Background and Aims Improving crops requires better linking of traits and metabolic processes to whole plant performance. In this paper, we present CN-Wheat, a comprehensive and mechanistic model of carbon (C) and nitrogen (N) metabolism within wheat culms after anthesis.Methods The culm is described by modules that represent the roots, photosynthetic organs and grains. Each of them includes structural, storage and mobile materials. Fluxes of C and N among modules occur through a common pool and through transpiration flow. Metabolite variations are represented by differential equations that depend on the physiological processes occurring in each module. A challenging aspect of CN-Wheat lies in the regulation of these processes by metabolite concentrations and the environment perceived by organs.Key Results CN-Wheat simulates the distribution of C and N into wheat culms in relation to photosynthesis, N uptake, metabolite turnover, root exudation and tissue death. Regulation of physiological activities by local concentrations of metabolites appears to be a valuable feature for understanding how the behaviour of the whole plant can emerge from local rules.Conclusions The originality of CN-Wheat is that it proposes an integrated view of plant functioning based on a mechanistic approach. The formalization of each process can be further refined in the future as knowledge progresses. This approach is expected to strengthen our capacity to understand plant responses to their environment and investigate plant traits adapted to changes in agronomical practices or environmental conditions. A companion paper will evaluate the model.

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Studies of the Uptake of Nitrate in Barley

Abstract: 8,11,18,20,23,29 N03-PretreatmentsEffects of four different NO3-pretreatments on the kinetics of NO3-influx were investigated in 7 d old plants. The

Cited by 382 publications

References 18 publications

Nitrate transporters: an overview in legumes

Nitrate transporters: an overview in legumes

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

CN-Wheat, a functional–structural model of carbon and nitrogen metabolism in wheat culms after anthesis. I. Model description

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