Abstract
Wheat plants grown during 10 days in the absence of N were pretreated with 1.0 eq m-3 of methionine, asparagine or glutamine and/or 1.0 eq m-3 MSX4 or 0.17 eq m-3 DON. Net NH4 + uptake was measured both in the presence or in the absence of the amino acid or enzyme inhibitor used in the pretreatment. The effect of met, asn and gln on net K+ uptake was also studied using K+-depleted plants. Changes in the contents of root free NH4 +, asn, gln and the activities of GS, PEP-carboxylase, NAD+-GDH and NADH-GDH were determined. Net NH4 + uptake in gln and asn pretreated plants was markedly, and sometimes completely suppressed provided uptake was measured in the presence of the amides. On the other hand, the met pretreated plants absorbed only 35% less NH4 + than the control. When NH4 + uptake was measured in the absence of the amino acids, only those plants pretreated with asn showed a marked suppression of net uptake during the first 120 min. None of the 3 amino acids tested significantly inhibited K+ uptake. Free NH4 + concentration in roots of N-starved plants increased after 4 h incubation with gln, asn or MSX in the absence of external NH4 +. Nevertheless, no correlation was observed between root NH4 + concentration and the extent of net NH4 + uptake suppression. The inhibitory effect exerted by asn decreased when it was supplied together with MSX or DON. Pretreatments with gln or asn in the absence of external NH4 + significantly increased the level of asn in the roots, while that of gln remained unchanged. It is concluded that asn and gln specifically suppress net NH4 + uptake in wheat, although it is not clear wether they act only from the root exterior, or through an endogenous pool exhibiting fast turn-over.
Similar content being viewed by others
Abbreviations
- AUR:
-
ammonium uptake rate
- DON:
-
6-diazo-5-oxo-L-norleucine
- GDH:
-
glutamic dehydrogenase
- GOGAT:
-
oxoglutarate- glutamine aminotransferase
- GS:
-
glutamine synthetase
- MSX:
-
L-methionine sulfoximine
- PEP:
-
phosphoenolpyruvate
- PVPP:
-
polyvinylpolypyrrolidone
References
Allen, S and Smith, J 1986 Ammonium nutrition in Ricinus communis: Its effect on plant growth and the chemical composition of the whole plant, xylem and phloem saps. J. Exp. Bot. 37, 1599–1610.
Breteler, H and Arnozis, P A 1985 Effect of amino compounds on nitrate utilization by roots of dwarf bean. Phytochemistry 24, 653–657.
Cataldo, D, Schrader, L and Youngs, V 1974 Analysis by digestion and colorimetric assay of total nitrogen in plant tissues high in nitrate. Crop Sci. 14, 854–856.
Causin, H F and Arnozis, P A 1988 Effect of different sources of N on the growth of sugarbeet. Ciencia del Suelo 6, 129–135.
Causin, H F and Barneix, A J 1993 Regulation of NH4 + uptake in wheat plants: Effect of root ammonium concentration and amino acids. Plant and Soil 151, 211–218.
Clarkson, D T, Saker, L R and Purves, J V 1989 Depression of nitrate and ammonium transport in barley plants with diminished sulphate status: Evidence of co-regulation of sulphate and nitrogen intake. J. Exp. Bot. 218, 953–963.
Etherthon, B and Rubinstein, B 1977 Evidence for amino acid-H+ cotransport in oat coleoptiles. Plant Physiol. 59, 117 (Abs).
Ferguson, A R and Sims, A P 1974 The regulation of glutamine metabolism in Cadida utilis: The inactivation of glutamine synthetase. J. Gen. Microbiol. 80, 173–185.
Gashaw, L and Mugwira, L M 1981 Ammonium-N and nitrate-N effects on the growth and mineral composition of triticale, wheat and rye. Agron. J. 73, 47–51.
Givan, C V 1979 Metabolic detoxification of ammonia in tissues of higher plants. Phytochemistry 18, 375–382.
Ikeda, M and Yamada, Y 1981 Dark CO2 fixation in leaves of tomato plants grown with NH4 + and NO3 - as nitrogen sources. Plant and Soil 60, 312–322.
Jackson, W A, Kwik, K D and Volk, R J 1976 Nitrate influx and efflux by intact wheat seedligs: Effect of prior nitrate nutrition. Planta 192, 149–156.
Jackson, W A and Volk, R J 1992 Nitrate and ammonium uptake by maize: adaptation during relief from nitrogen suppression. New Phytol. 122, 439–446.
Joy, K W 1988 Ammonia, glutamine and asparagine: A carbonnitrogen interface. Can. J. Bot. 66, 2103–2109.
Kropf, D L, Kaldwell, J H, G.ow, N A R and Harold, F M 1984 Transcellular ion currents in the water mold Achlya: Amino acid proton symport as a mechanism of current entry. J. Cell Biol 99, 486–496.
Lee, R B and Rudge, K A 1986 Effect of nitrogen defficiency on the absorption of nitrate and ammonium by barley plants. Ann. Bot. 57, 471–486.
Lewis, O A M, Chadwick, S and Withers, J 1983 The assimilation of ammonium by barley roots. Planta 159, 483–486.
Magalhaes, J R, Huber, D M and Tsai, C I 1992 Evidence of increased 15N-ammonium assimilation in tomato plants with exogenous α-ketoglutarate. Plant Sci. 85, 135–141.
Morgan, M A and Jackson, W A 1988 Inward and outward movement of ammonium in root systems: Transient responses during recovery from nitrogen deprivation in presence of ammonium. J. Exp. Bot. 199, 179–191.
Morgan, M A and Jackson, W A 1989 Reciprocal ammonium transport into and out of plant roots: Modifications by plant nitrogen status and elevated root ammonium concentration. J. Exp. Bot. 211, 207–214.
Muller, B and Touraine, B 1992 Inhibition of NO3 uptake by various phloem translocated amino acids in soybean seedlings. J. Exp. Bot. 43, 617–623.
Oji, Y and Izawa, G 1972 Quantitative changes of free amino acids and amides in barley plants during ammonia and nitrate assimilation. Plant Cell Physiol. 13, 249–259
Reisenauer, H M 1978 Absorption and utilization of ammonium nitrogen by plants. In Nitrogen in the Environment (2), Ed D R Nielsen and J G Donald. pp 157–191. Academic Press. N. Y.
Rhodes, D, Rendon, G A and Stewart, G R 1975 The control of glutamine synthetase level in Lemna minor L. Planta (Berl.) 125, 201–211.
Rhodes, D, Rendon, G A and Stewart, G R 1976 The regulation of ammonia assimilation enzymes in Lemna minor. Planta (Berl.) 129, 203–210.
Robinson, S A, Slade, A P, Fox, G G, Phillips, R, Ratcliffe, R G and Stewart, G R 1991 The role of glutamate dehydrogenase in plant nitrogen metabolism. Plant Physiol. 95, 509–516.
Rodgers, C O and Barneix, A J 1993 The effect of amino acids on the regulation of nitrate uptake by wheat seedlings. J. Pl. Nutr. 16, 337–348.
Salsac, L, Chaillou, S, Morot-Gaudry, J F, Lesaint, C and Jolivet, E 1987 Nitrate and ammonium nutrition in plants. Plant Physiol. Biochem. 25, 805–812.
Singh, R P and Srivastava, H S 1983 Regulation of glutamate dehydrogenase activity by amino acids in maize seedlings. Physiol. Plant. 57, 549–554.
Slaughter, J C, Mc Kernan, G and Saita, M 1990 Intracellular asparagine pool as a factor in control of ammonium uptake by Saccharomyces cerevisiae. Mycol. Res. 94 1009–1012.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Causin, H.F., Barneix, A.J. The effect of glutamine and asparagine on net NH4 + uptake in young wheat plants. Plant Soil 161, 257–265 (1994). https://doi.org/10.1007/BF00046397
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF00046397