Skip to main content
Plant Physiology logoLink to Plant Physiology
. 1973 Dec;52(6):513–517. doi: 10.1104/pp.52.6.513

Effects of Helminthosporium carbonum Toxin on Nitrate Uptake and Reduction by Corn Tissues 1,2

O C Yoder a,3, R P Scheffer a
PMCID: PMC366535  PMID: 16658595

Abstract

Susceptible corn tissues exposed to the host-specific toxin of Helminthosporium carbonum race 1 reduced more nitrate to nitrite than did control tissues, as measured by an in vivo method. There were no differences in nitrate reductase activities extracted from treated and control tissues and assayed by an in vitro method. Toxin-treated susceptible roots removed nitrate from solution and accumulated it in the tissues twice as fast as did control roots. Uptake by resistant roots was stimulated also, provided approximately 100 times higher concentrations of toxin were used. Toxin-stimulated nitrate uptake occurred in the presence of tungstate, which eliminates nitrate reductase activity. Toxin did not cause leakage of nitrate from roots under these conditions. Thus, toxin-enhanced nitrate accumulation was caused by increased nitrate uptake rather than by decreased nitrate metabolism or decreased nitrate leakage. The data indicate that toxin increases the rate of nitrate reduction in vivo by increasing the availability of substrate, not by stimulation of enzyme synthesis.

Full text

PDF
513

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Dure L. S. Gross Nutritional Contributions of Maize Endosperm and Scutellum to Germination Growth of Maize Axis. Plant Physiol. 1960 Nov;35(6):919–925. doi: 10.1104/pp.35.6.919. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Ferrari T. E., Varner J. E. Control of nitrate reductase activity in barley aleurone layers. Proc Natl Acad Sci U S A. 1970 Mar;65(3):729–736. doi: 10.1073/pnas.65.3.729. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Ferrari T. E., Yoder O. C., Filner P. Anaerobic nitrite production by plant cells and tissues: evidence for two nitrate pools. Plant Physiol. 1973 Mar;51(3):423–431. doi: 10.1104/pp.51.3.423. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Filner P. Regulation of nitrate reductase in cultured tobacco cells. Biochim Biophys Acta. 1966 May 5;118(2):299–310. doi: 10.1016/s0926-6593(66)80038-3. [DOI] [PubMed] [Google Scholar]
  5. Heimer Y. M., Filner P. Regulation of the nitrate assimilation pathway in cultured tobacco cells. 3. The nitrate uptake system. Biochim Biophys Acta. 1971 Feb 23;230(2):362–372. doi: 10.1016/0304-4165(71)90223-6. [DOI] [PubMed] [Google Scholar]
  6. Heimer Y. M., Wray J. L., Filner P. The effect of tungstate on nitrate assimilation in higher plant tissues. Plant Physiol. 1969 Aug;44(8):1197–1199. doi: 10.1104/pp.44.8.1197. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. Miller R. J., Koeppe D. E. Southern corn leaf blight: susceptible and resistant mitochondria. Science. 1971 Jul 2;173(3991):67–69. doi: 10.1126/science.173.3991.67. [DOI] [PubMed] [Google Scholar]
  8. Oaks A., Wallace W., Stevens D. Synthesis and turnover of nitrate reductase in corn roots. Plant Physiol. 1972 Dec;50(6):649–654. doi: 10.1104/pp.50.6.649. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. Pringle R. B. Chemical constitution of the host-specific toxin of Helminthosporium carbonum. Plant Physiol. 1970 Jul;46(1):45–49. doi: 10.1104/pp.46.1.45. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. Schrader L. E., Ritenour G. L., Eilrich G. L., Hageman R. H. Some characteristics of nitrate reductase from higher plants. Plant Physiol. 1968 Jun;43(6):930–940. doi: 10.1104/pp.43.6.930. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. Smith F. W., Thompson J. F. Regulation of nitrate reductase in excised barley roots. Plant Physiol. 1971 Aug;48(2):219–223. doi: 10.1104/pp.48.2.219. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. Yoder O. C., Scheffer R. P. Effects of Helminthosporium carbonum Toxin on Absorption of Solutes by Corn Roots. Plant Physiol. 1973 Dec;52(6):518–523. doi: 10.1104/pp.52.6.518. [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. Zielke H. R., Filner P. Synthesis and turnover of nitrate reductase induced by nitrate in cultured tobacco cells. J Biol Chem. 1971 Mar 25;246(6):1772–1779. [PubMed] [Google Scholar]

Articles from Plant Physiology are provided here courtesy of Oxford University Press

RESOURCES