The determination of nitrogen in agricultural materials by the nessler reagent. I.—preparation of the reagent

Yuen, S. H.; Pollard, A. G.

doi:10.1002/jsfa.2740031002

Cited by 63 publications

(24 citation statements)

References 13 publications

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“…The residue was resuspended in water. Ammonium was isolated from this solution by isothermic distillation and then determined colorimetrically at 436 nm using Nessler reagent (Yuen and Polland 1952).…”

Section: Methodsmentioning

confidence: 99%

Leaf-specific overexpression of plastidic glutamine synthetase stimulates the growth of transgenic tobacco seedlings

Migge

Carrayol

Hirel

et al. 2000

Planta

110

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The impact of increased plastidic glutamine synthetase (GS-2; EC 6.1. 3.2) activity on foliar amino-acid levels and on biomass production was examined in transgenic tobacco. For that, tobacco was transformed via Agrobacterium tumefaciens with a binary vector containing a tobacco GS-2 cDNA downstream of the leaf-specific soybean ribulose-1,5-bisphosphate carboxylase/oxygenase small subunit gene promotor. Two transgenic tobacco lines with 15- to 18-fold higher foliar GS-2 transcript levels than the wild type were obtained. The GS-2 protein pools and the specific GS-2 activities were, however, only 2- to 2.3-fold higher in the leaves of the transgenic plants than in the leaves of the wild type. This discrepancy may reflect a post-transcriptional control of GS-2 protein accumulation. The increased GS-2 activity was correlated with a decrease in the leaf ammonium pool (3.7-fold) and an increase in the levels of some free amino acids, including glutamate (2. 5-fold) and glutamine (2.3-fold). The accumulation of soluble protein per unit fresh weight, however, remained unchanged. This result indicates that a process downstream of the synthesis of the primary organic products of N-assimilation is limiting leaf protein accumulation. Nevertheless, the overexpression of GS-2 stimulated the growth rate of the transgenic tobacco seedlings which, consequently, were larger (20-30% on a fresh-weight basis) than wild-type seedlings grown under identical conditions. This result suggests that GS-2 is the rate-limiting enzyme during biomass production in tobacco seedlings. The requirement for glutamate as the ammonium acceptor in the reaction catalysed by GS-2 may imply that there is co-regulation of GS-2 and ferredoxin dependent glutamate synthase (Fd-GOGAT; EC 1.4.7.1) gene expression. Increased leaf GS-2 activity had, however, no influence on the foliar Fd-GOGAT protein abundance. This result suggests that in tobacco leaves, more Fd-GOGAT is present than required to meet the demands of primary ammonium assimilation and that there is no strong interdependence between GS-2 and Fd-GOGAT protein expression.

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Section: Methodsmentioning

confidence: 99%

Leaf-specific overexpression of plastidic glutamine synthetase stimulates the growth of transgenic tobacco seedlings

Migge

Carrayol

Hirel

et al. 2000

Planta

110

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“…The culture media were aerated throughout the incubation period. The ammonia concentration of the media was regularly analysed by withdrawing samples and determining ammonia colorimetrically (Yuen & Pollard, 1952).…”

Section: Methodsmentioning

confidence: 99%

The involvement of glutamate dehydrogenase and glutamine synthetase/glutamate synthase in ammonia assimilation by the basidiomycete fungus Stropharia semiglobata

Schwartz

Misri

Fock

1991

Journal of General Microbiology

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~When grown on ammonia as sole nitrogen source, the basidiomycete fungus Stropharia semigfobatu assimilated nitrogen via glutamate dehydrogenase (GDH). The two isoenzymes of GDH were both repressed by increasing concentrations of ammonia, but NADP-GDH (EC 1.4.1.4) was far more active than NAD-GDH (EC 1.4.1.2). Glutamine synthetase (GS; EC 6.3.1.2) and glutamate synthase (GOGAT; EC 1.4.7.1) were also active in S. semigfobatu and these enzyme activities were independent of the ammonia concentration in the suspension. From enzyme activity and lSN-labelling studies of amino acids, it is concluded that both GDH and GS/GOGAT contribute to ammonia assimilation in this fungus.

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“…The plant samples were then ground and analyzed for N concentration using Nessler's reagent (Yuen and Pollard, 1952) after the samples were digested with H 2 SO 4 /H 2 O 2 (Bao, 2005). The analyses of K and P concentrations in the digests were conducted using a Thermo Electron Corp. IRIS Intrepid II Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES) (Waltham, MA, USA).…”

Section: Measurements and Calculationmentioning

confidence: 99%

Different responses of two Mosla species to potassium limitation in relation to acid rain deposition

Wang

et al. 2009

J. Zhejiang Univ. Sci. B

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Abstract:The increasingly serious problem of acid rain is leading to increased potassium (K) loss from soils, and in our field investigation, we found that even congenerically relative Mosla species show different tolerance to K-deficiency. A hydroponic study was conducted on the growth of two Mosla species and their morphological, physiological and stoichiometric traits in response to limited (0.35 mmol K/L), normal (3.25 mmol K/L) and excessive (6.50 mmol K/L) K concentrations. Mosla hangchowensis is an endangered plant, whereas Mosla dianthera a widespread weed. In the case of M. hangchowensis, in comparison with normal K concentration, K-limitation induced a significant reduction in net photosynthetic rate (P n ), soluble protein content, and superoxide dismutase (SOD) activity, but an increase in malondialdehyde (MDA) concentration. However, leaf mass ratio (LMR) and root mass ratio (RMR) were changed little by K-limitation. In contrast, for M. dianthera, K-limitation had little effect on P n , soluble protein content, SOD activity, and MDA concentration, but increased LMR and RMR. Critical values of N (nitrogen):K and K:P (phosphorus) ratios in the shoots indicated that limitation in acquiring K occurred under K-limited conditions for M. hangchowensis but not for M. dianthera. We found that low K content in natural habitats was a restrictive factor in the growth and distribution of M. hangchowensis, and soil K-deficiency caused by acid rain worsened the situation of M. hangchowensis, while M. dianthera could well acclimate to the increasing K-deficiency. We suggest that controlling the acid rain and applying K fertilizers may be an effective way to rescue the endangered M. hangchowensis.

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The determination of nitrogen in agricultural materials by the nessler reagent. I.—preparation of the reagent

Cited by 63 publications

References 13 publications

Leaf-specific overexpression of plastidic glutamine synthetase stimulates the growth of transgenic tobacco seedlings

Leaf-specific overexpression of plastidic glutamine synthetase stimulates the growth of transgenic tobacco seedlings

The involvement of glutamate dehydrogenase and glutamine synthetase/glutamate synthase in ammonia assimilation by the basidiomycete fungus Stropharia semiglobata

Different responses of two Mosla species to potassium limitation in relation to acid rain deposition

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