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Glutamine-synthetase isoforms appearing in sunflower cotyledons during germination

Effects of light and nitrate

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Abstract

Ion-exchange chromatography has been used to separate the isoforms of glutamine synthetase (GS; EC 6.3.1.2) appearing in sunflower (Helianthus annuus L. cv. Peredovic) cotyledons during seedling growth under different light and nitrogen conditions. Both in dry and imbibed seeds, only a single form of GS (GSs) was detected. Upon seed germination, the GSs isoform was gradually replaced by cytosolic (GS1) and plastidic (GS2) isoforms. Light and nitrate decreased the levels of GS1. In contrast, the appearance of GS2 was greatly stimulated by light. Nitrate also had a positive effect, particularly in the light. Light and nitrate acted synergistically on the appearance of GS2. The GS2:GS1 ratio in cotyledons of 9-d-old seedlings ranged from about 2, in darkness and nitrate-deprivation conditions, to 16 under light and nitrate application. The possible physiological roles of the distinct GS isoforms appearing in the epigeal cotyledons of sunflower during germination, and their differential regulation by light and nitrate, are discussed.

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Abbreviations

GS:

glutamine synthetase

GS1 :

cytosolic GS

GS2 :

plastidic GS

GSs :

GS from seeds

References

  • Agüera, E., de la Haba, P., Maldonado, J.M. (1987) Induction of nitrate reductase, nitrite reductase and glutamine synthetase by nitrate and/or nitrite in germinating sunflower cotyledons. Effect of plant hormones. Plant Physiol. (Life Sci. Adv.) 6, 255–258

    Google Scholar 

  • Bennett, M.J., Cullimore, J.V. (1989) Glutamine synthetase isoenzymes of Phaseolus vulgaris L.: subunit composition in developing root nodules and plumules. Planta 179, 433–440

    Google Scholar 

  • Cabello, P., de la Haba, P., Maldonado, J.M. (1991) Isoforms of glutamine synthetase in cotyledons, leaves and roots of sunflower plants. J. Plant Physiol. 137, 378–380

    Google Scholar 

  • Coruzzi, G.M. (1991) Molecular approaches to the study of amino acid biosynthesis in plants. Plant Sci. 74, 145–155

    Google Scholar 

  • Cullimore, J.V., Bennett, M.J. (1988) The molecular biology and biochemistry of plant glutamine synthetase from root nodules of Phaseolus vulgaris L. and other legumes. J. Plant Physiol. 132, 387–393

    Google Scholar 

  • de la Haba, P., Agüera, E., Maldonado, J.M. (1988) Development of nitrogen-assimilating enzymes in sunflower cotyledons during germination as affected by the exogenous nitrogen source. Planta 173, 52–57

    Google Scholar 

  • Edwards, J.W., Coruzzi, G.M. (1989) Photorespiration and light act in concert to regulate the expression of the nuclear gene for chloroplast glutamine synthetase. Plant Cell 1, 241–248

    Google Scholar 

  • Hewitt, EJ. (1966) Sand and water culture methods used in the study of plant nutrition. Commonwealth Bureau of Horticultural and Plantation Crops, East Mailing Tech. Commun. No. 22

  • Hirel, B., Vidal, J., Gadal, P. (1982) Evidence for a cytosolic-dependent light induction of chloroplastic glutamine synthetase during greening of etiolated rice leaves. Planta 155, 17–23

    Google Scholar 

  • Lea, P.J., Miflin, B.J. (1979) Photosynthetic ammonia assimilation. In: Encyclopedia of plant physiology, N.S., vol. 6: Photosynthesis II, pp. 445–456, Gibbs, M., Latzko, E., eds. Springer, Berlin Heidelberg New York

    Google Scholar 

  • Lea, P.J., Joy, K.W. (1983) Amino acid interconversion in germinating seeds. In: Recent advances in phytochemistry, vol. 17: Mobilization of reserves in germination, pp. 77–109, Nozzolillo, C., Lea, P.J., Loewus, F.A., eds. Plenum Press, New York London

    Google Scholar 

  • Lea, P.J., Robinson, S.A., Stewart, G.R. (1990) The enzymology and metabolism of glutamine, glutamate, and asparagine. In: The biochemistry of plants, vol. 16: Intermediary nitrogen metabolism, pp. 121–159, Miflin, B.J., Lea, P.J., eds. Academic Press, San Diego London

    Google Scholar 

  • Mäck, G., Tischner, R. (1990) Glutamine synthetase oligomers and isoforms in sugarbeet (Beta vulgaris L.). Planta 181, 10–17

    Google Scholar 

  • Mann, A.F., Fentem, P.A., Stewart, G.R. (1979) Identification of two forms of glutamine synthetase in barley (Hordeum vulgare). Biochem. Biophys. Res. Commun. 88, 515–521

    Google Scholar 

  • McNally, S.F., Hirel, B., Gadal, P., Mann, A.F., Stewart, G.R. (1983) Glutamine synthetases of higher plants. Evidence for a specific isoform content related to their physiological role and their compartmentation within the leaf. Plant Physiol. 72, 22–25

    Google Scholar 

  • Sakamoto, A., Takeba, G., Shibata, D., Tanaka, K. (1990) Phytochrome-mediated activation of the gene for cytosolic glutamine-synthetase (GS1) during imbibition of photosensitive lettuce seeds. Plant Mol. Biol. 15, 317–323

    Google Scholar 

  • Schmidt, S., Mohr, H. (1989) Regulation of the appearance of glutamine synthetase in mustard (Sinapis alba L.) cotyledons by light, nitrate and ammonium. Planta 177, 526–534

    Google Scholar 

  • Schuster, C., Oelmüller, R., Mohr, H. (1987) Signal storage in phytochrome action on nitrate-mediated induction of nitrate and nitrite reductases in mustard seedling cotyledons. Planta 171, 136–143

    Google Scholar 

  • Tingey, S.V., Tsai, F.-Y., Edwards, J.W., Walker, E.L., Coruzzi, G.M. (1988) Chloroplast and cytosolic glutamine synthetase are encoded by homologous nuclear genes which are differentially expressed in vivo. J. Biol. Chem. 263, 9651–9657

    Google Scholar 

  • Wallsgrove, R.M., Turner, J.C., Hall, N.P., Kendally, A.C., Bright, S.W.J. (1987) Barley mutants lacking chloroplast glutamine synthetase. Biochemical and genetic analysis. Plant Physiol. 83, 155–158

    Google Scholar 

  • Weber, M., Schmidt, S., Schuster, C., Mohr, H. (1990) Factors involved in the coordinate appearance of nitrite reductase and glutamine synthetase in the mustard (Sinapis alba L.) seedling. Planta 180, 429–434

    Google Scholar 

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This work was supported by a grant from Dirección General de Investigatión Científica y Técnica (PB90-0777) and Plan Andaluz de Investigación (3261), Spain. P.C. gratefully acknowledges receipt of a scholarship from Junta de Andalucía. The valuable technical assistance of Mrs. G. Alcalá is greatly appreciated. We are also grateful to Eurosemillas (Córdoba) for supplying us with sunflower seeds.

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de la Haba, P., Cabello, P. & Maldonado, J.M. Glutamine-synthetase isoforms appearing in sunflower cotyledons during germination. Planta 186, 577–581 (1992). https://doi.org/10.1007/BF00198038

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