Springer Nature is making SARS-CoV-2 and COVID-19 research free. View research | View latest news | Sign up for updates

Rapid activation by phytochrome of nitrate reductase in the cotyledons of Sinapis alba


Nitrate reductase in the cotyledons of etiolated seedlings of Sinapis alba L. responds rapidly to the addition of nitrate. The response is inhibited by cycloheximide at low concentrations. The enzyme is also under phytochrome control. Five minutes of red light irradiation leads instantaneously to a 45% increase in enzyme activity. Increases in activity, linear with respect to time and with no lag phases are promoted by continuous far-red or blue irradiation. These increases are insensitive to cycloheximide. Thus, light and nitrate act through different mechanisms in controlling nitrate reductase activity and phytochrome does not act via controlling the rate of synthesis of the enzyme.

This is a preview of subscription content, log in to check access.


cot pr:

pair of cotyledons


  1. Attridge, T.H., Smith, H.: Evidence for a pool of inactive phenylalanine ammonia-lyase in Cucumis sativus seedlings. Phytochemistry 12, 1569–1574 (1973)

  2. Attridge, T.H., Johnson, C.B., Smith, H.: Density-labelling evidence for the phytochrome mediated activation of phenylalanine ammonia-lyase in mustard cotyledons. Biochim. biophys. Acta (Amst.) 343, 440–451 (1974)

  3. Beevers, L., Hageman, R.H.: Nitrate reduction in higher plants. Ann. Rev. Plant Physiol. 20, 495–522 (1969)

  4. Beevers, L., Hageman, R.H.: The role of light in nitrate metabolism in higher plants. Photophysiology 7, 85–113 (1972)

  5. Candella, M.I., Fisher, E.G., Hewitt, E.J.: Molybdenum as a plant nutrient X. Some factors affecting the activity of nitrate reductase in cauliflower plants grown with different nitrogen sources and molybdenum levels in sand cultures. Plant Physiol. 32, 280–288 (1957)

  6. Filner, P.: Regulation of nitrate reductase in cultured tobacco cells. Biochim. biophys. Acta (Amst.) 118, 299–310 (1966)

  7. Hartmann, K.M.: Ein Wirkungsspektrum der Photomorphogenese unter Hochenergiebedingungen und seine Interpretation auf der Basis des Phytochroms (Hypokotylwachstumshemmung bei Lactua sativa L.). Z. Naturforsch. 226, 1172–1175 (1967)

  8. Hewitt, E.J.: Some aspects of micronutrient element metabolism in plants. Nature (Lond.) 180, 1020–1022 (1957)

  9. Jakobs, M., Mohr, H.: Kinetische Studien zur phytochrominduzierten Proteinsynthese. Planta (Berl.) 69, 187–197 (1966)

  10. Jones, R.W., Sheard, R.W.: Nitrate reductase activity: phytochrome mediation of induction in etiolated peas. Nature, New Biol. 238, 221–222 (1972)

  11. Jones, R.W., Sheard, R.W.: Phytochrome, nitrate movement and induction of nitrate reductase in etiolated pea terminal buds. Plant Physiol. 55, 954–959 (1975)

  12. Lorimer, G.H., Gewitz, H.S., Völker, W., Solomonson, L.P., Vennesland, B.: The presence of bound cyanide in the naturally inactivated form of nitrate reductase of Chlorella vulgaris. J. biol. Chem. 249, 6074–6079 (1974)

  13. Mohr, H.: Lectures on photomorphogenesis. Berlin-Heidelberg-New York: Springer 1972

  14. Nicholas, D.J.D., Nason, A.: Molybdenum and nitrate reductase. II. Molybdenum as a constituent of nitrate reductase. J. biol. Chem. 207, 353–360 (1954)

  15. Notton, B.A., Hewitt, E.J.: The role of tungsten in the inhibition of nitrate reductase activity in spinach (Spinacea oleracea) leaves. Biochem. biophys. Res. Commun. 44, 702–710 (1971)

  16. Sawhney, S.K., Naik, M.S.: Role of light in the synthesis of nitrate reductase and nitrite reductase in rice seedlings. Biochem. J. 130, 475–485 (1972)

  17. Smith, H.: Phytochrome mediated assembly of polyribosomes in etiolated bean leaves: evidence for post-transcriptional control of development. Europ. J. Biochem. (in press)

  18. Solomonson, L.P., Jetschmann, K., Vennesland, B.: Reversible inactivation of the nitrate reductase of Chlorella vulgaris Beijerinck. Biochem. biophys. Acta (Amst.) 309, 32–43 (1973)

  19. Stewart, G.R., Lee, J.A., Orebamjo, T.O.: Nitrogen metabolism of halophytes. II. Nitrate availability and utilization. New Phytologist 72, 539–546 (1973)

  20. Travis, R.L., Key, J.L.: Correlation between polyribosome level and the ability to induce nitrate reductase in dark grown corn seedlings. Plant Physiol. 48, 617–620 (1971)

  21. Wallace, W.: A nitrate reductase inactivating enzyme from the maize root. Plant Physiol. 52, 197–201 (1973)

  22. Zielke, H.R., Filner, P.: Synthesis and turnover of nitrate reductase induced by nitrate in cultured tobacco cells. J. biol. Chem. 246, 1772–1779 (1971)

Download references

Author information

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Johnson, C.B. Rapid activation by phytochrome of nitrate reductase in the cotyledons of Sinapis alba . Planta 128, 127–131 (1976).

Download citation


  • Enzyme
  • Nitrate
  • Enzyme Activity
  • Alba
  • Nitrate Reductase