Abstract
L-methionine sulphoximine, a potent inhibitor of glutamine synthetase decreased nitrate reductase activity by 50% at the end of 12h of treatment while nitrite reductase was insignificantly affected. By 3 h the inhibition of glutamine synthetase activity was complete. Elevated levels of ammonia induced by L-methionine sulphoximine did not influence glutamate dehydrogenase. It is inferred that ammonia accumulation does not affect photosynthetic electron transport which supplies reducing power to nitrite reductase. The failure of glutamate dehydrogenase activity to be induced by high ammonium levels shows that it is not involved in the process of ammonia assimilation in the leaves.
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Abrol Y P, Sawhney S K and Naik M S 1983 Light and dark assimilation of nitrate in plants;Plant Cell Environ. 6 595
Achhireddy N, Vann D R, Fletcher J S and Beevers L 1983 The influence of methionine sulphoximine on photosynthesis and nitrogen metabolism in excised pepper (Capsicum annuum) leaves;Plant Sci. Lett. 32 73
Barash I, Sadon T and Mor H 1973 Evidence for ammonium dependentde novo synthesis of glutamate dehydrogenase in detached oat leaves;Plant Physiol. 56 856
Beevers L and Hageman R H 1983 Uptake and reduction of nitrate 1. Bacteria and higher plants;Encycl. Plant Physiol. New Ser. A15 351–375
Cammaerts D and Jacobs M 1985 A study of the role of glutamate dehydrogenase in the nitrogen metabolism ofArabidopsis thaliana;Planta 163 517
Florencio F J and Vega J M 1983 Utilization of nitrate, nitrite and ammonium byChlamydomonas reinhardii;Planta 158 288
Givan C V 1979 Metabolic detoxification of ammonia in tissues of higher plants;Phytochemistry 20 933
Ikeda M, Ogren W L and Hageman R H 1984 Effect of methionine sulfoximine on photosynthetic carbon metabolism in wheat leaves;Plant Cell Physiol. 25 447
Keys A J, Bird I F, Cornelius M J, Lea P J, Wallsgrove R M and Miflin B J 1978 Photorespiratory nitrogen cycle;Nature (London) 275 741
Klepper L, Flesher D and Hageman R H 1971 Generation of reduced nicotinamide adenine dinucleotide for nitrate reduction in green leaves;Plant Physiol. 48 580
Kumar P A and Abrol Y P 1990 Ammonia assimilation in higher plants; inNitrogen in higher plants (ed.) Y P Abrol (London: Research Studies Press) (in press)
Kumar P A, Nair T V R and Abrol Y P 1983 Effect of exogenous supply of amino acids, amide, urea and ureide on free NH +4 level in the leaves of mungbean;Experientia 39 1302
Kumar P A, Nair T V R and Abrol Y P 1984 Effect of photorespiratory metabolites, inhibitors and methionine sulphoximine on the accumulation of ammonia in the leaves of mungbean and Amaranthus;Plant Sci. Lett. 33 303
Martin F, Winspear M J, McFarlane J D and Oaks A 1983 Effect of methionine sulfoximine on the accumulation of ammonia in C3 and C4 leaves;Plant Physiol. 71 177
Mohanty B and Fletcher J S 1980 Ammonium influence on nitrogen accumulating enzymes and protein accumulation in suspension cultures of Paul's Scarlet rose;Physiol. Plant. 48 453
Platt S G and Anthon G L 1981 Ammonia accumulation and inhibition of photosynthesis in methionine sulfoximine treated spinach;Plant Physiol. 67 509
Singh P, Kumar P A, Abrol Y P and Naik M S 1985 Photorespiratory nitrogen cycle—A critical evaluation;Physiol. Plant. 66 169
Walker K A, Keys A J and Givan C V 1984 Effect of L-methionine sulphoximine on the products of photosynthesis in wheat (Triticum aestivum) leaves;J. Exp. Bot. 35 1800
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Kumar, P.A., Abrol, Y.P. Effect of L-methionine sulphoximine on the enzymes of nitrogen metabolism in barley leaves. Proc. Indian Acad. Sci. 100, 97–100 (1990). https://doi.org/10.1007/BF03053431
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DOI: https://doi.org/10.1007/BF03053431