Advertisement

Influence of Light and CO2 on Nitrate Assimilation by Barley Seedlings

  • M. Aslam
  • R. C. Huffaker
  • D. W. Rains
  • K. P. Rao

Abstract

Although the role of light in nitrate assimilation has been studied extensively (Beevers and Hageman, dy1969, 1972), controversy continues as to whether nitrate reduction normally occurs in darkness. Nitrate reduction under anaerobic conditions has been reported in tissue slices in darkness; it was detected as nitrite accumulation in the medium (Atkins and Canvin, 1975; Klepper et al., 1971; Radin, 1973; Sawhney et al., dy1978a,b). Under aerobic conditions, however, nitrite does not accumulate in the dark (Aslam et al., 1979). That observation has been ascribed to two contradictory processes: 1) that O2 inhibited nitrate reduction (Atkins and Canvin, 1975; Sawhney et al., dy1978a,b); or 2) that both nitrate and nitrite reduction occurred in the presence of O2. This contradiction can be resolved by following each of the processes involved: nitrate uptake, accumulation, and reduction or at least the disappearance of the product (nitrite). When the appearance of nitrite is the only assay, it is not possible to determine whether nitrate reduction was inhibited by O2 or whether nitrite was further reduced. Either case would account for the inability to find nitrite in the incubation medium. Others did not find proof that 15NO3 converts into amino acids in barley leaves in darkness during short-term experiments (Canvin and Atkins, 1974). The purpose of this report was to describe nitrate and nitrite assimilation by barley seedlings in light and darkness.

Keywords

Nitrate Reductase Nitrate Reduction Nitrate Reductase Activity Nitrate Uptake Barley Seedling 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. Aslam, M., Huffaker, R. C., and Travis, R. L., 1973, The interaction of respiration and photosynthesis in induction of nitrate reductase activity, Plant Physiol., 52:137.PubMedCrossRefGoogle Scholar
  2. Aslam, M., Oaks, A., and Huffaker, R. C., 1976, Effect of light and glucose on the induction of nitrate reductase and on the distribution of nitrate in etiolated barley leaves, Plant Physiol., 58:588.PubMedCrossRefGoogle Scholar
  3. Aslam, M., Huffaker, R. C., Rains, D. W., and Rao, K. P., 1979, Influence of light and ambient carbon dioxide concentration on nitrate assimilation by intact barley seedlings, Plant Physiol., 63:1205.PubMedCrossRefGoogle Scholar
  4. Atkins, C. A., and Canvin, D. T., 1975, Nitrate, nitrite and ammonia assimilation by leaves. Effect of inhibitors, Planta, 123:41.CrossRefGoogle Scholar
  5. Beevers, L., and Hageman, R. H., 1969, Nitrate reduction in higher plants, Ann. Rev. Plant Physiol., 20:495.CrossRefGoogle Scholar
  6. Beevers, L., and Hageman, R. H., 1972, The role of light in nitrate metabolism in higher plants, in: “Photophysiology,” Vol. 7, A. C. Giese, ed., Academic Press, New York.Google Scholar
  7. Canvin, D. T., and Atkins, C. A., 1974, Nitrate, nitrite and ammonia assimilation by leaves: effect of light, carbon dioxide and oxygen, Planta, 116:207.CrossRefGoogle Scholar
  8. Chantarotwong, W., Huffaker, R. C., Miller, B. L., and Granstedt, R. C., 1976, in vivo nitrate reduction in relation to nitrate uptake, nitrate content and in. vitro nitrate reductase activity in intact barley seedlings, Plant Physiol., 57:519.PubMedCrossRefGoogle Scholar
  9. Jolly, S. O., and Tolbert, N. E., 1978, NADH-nitrate reductase inhibitor from soybean leaves, Plant Physiol., 62:197.PubMedCrossRefGoogle Scholar
  10. 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.PubMedCrossRefGoogle Scholar
  11. Neyra, C. A., and Hageman, R. H., 1976, Relationships between carbon dioxide, malate, and nitrate accumulation and reduction in corn (Zea mays L.) seedlings, Plant Physiol., 58:726.PubMedCrossRefGoogle Scholar
  12. Radin, J. W., 1973, In vivo assay of nitrate reductase in cotton leaf discs. Effect of oxygen and ammonium, Plant Physiol., 51:332.PubMedCrossRefGoogle Scholar
  13. Sawhney, S. K., Naik, M. S., and Nicholas, D. J. D., 1978a, Regulation of NADH supply for nitrate reduction in green plants via photosynthesis and mitochondrial respiration, Biochem. Biophys. Res. Commun., 81:1209.PubMedCrossRefGoogle Scholar
  14. Sawhney, S. K., Naik, M. S., and Nicholas, D. J. D., 1978b, Regulation of nitrate reduction by light. ATP and mitochondrial respiration in wheat leaves, Nature, 272:647.CrossRefGoogle Scholar
  15. Shaner, D. L., and Boyer, J. S., 1976, Nitrate reductase activity in maize (Zea mays L.) leaves. I. Regulation by nitrate flux, Plant Physiol., 58:499.PubMedCrossRefGoogle Scholar

Copyright information

© Plenum Press, New York 1981

Authors and Affiliations

  • M. Aslam
    • 1
  • R. C. Huffaker
    • 1
  • D. W. Rains
    • 1
  • K. P. Rao
    • 1
  1. 1.Plant Growth Laboratory and the Department of Agronomy and Range ScienceUniversity of CaliforniaDavisUSA

Personalised recommendations