Skip to main content
NCBI home page
Plant Physiology logoLink to Plant Physiology
. 1989 Oct;91(2):603–609. doi: 10.1104/pp.91.2.603

Effects of Carbohydrate on the Internal Oxygen Concentration, Oxygen Uptake, and Nitrogenase Activity in Detached Pea Nodules 1

Jonathan D Monroe 1,2,2, Thomas A LaRue 1,2
PMCID: PMC1062043  PMID: 16667075

Abstract

The interaction between carbon substrates and O2 and their effects on nitrogenase activity (C2H2) were examined in detached nodules of pea (Pisum sativum L. cv “Sparkle”). The internal O2 concentration was estimated from the fractional oxygenation of leghemoglobin measured by reflectance spectroscopy. Lowering the endogenous carbohydrate content of nodules by excising the shoots 16 hours before nodule harvest or by incubating detached nodules at 100 kPa O2 for 2 hours resulted in a 2- to 10-fold increase in internal O2, and a decline in nitrogenase activity. Conversely, when detached nodules were supplied with 100 millimolar succinate, the internal O2 was lowered. Nitrogenase activity was stimulated by succinate but only at high external O2. Oxygen uptake increased linearly with external O2 but was affected only slightly by the carbon treatments. The apparent diffusion resistance in the nodule cortex was similar in all of the treatments. Carbon substrates can thus affect nitrogenase activity indirectly by affecting the O2 concentration within detached nodules.

Full text

PDF
603

Selected References

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

  1. Halhoul M. N., Kleinberg I. Differential determination of glucose and fructose, and glucose- and fructose-yielding substances with anthrone. Anal Biochem. 1972 Dec;50(2):337–343. doi: 10.1016/0003-2697(72)90042-5. [DOI] [PubMed] [Google Scholar]
  2. Hunt S., King B. J., Canvin D. T., Layzell D. B. Steady and nonsteady state gas exchange characteristics of soybean nodules in relation to the oxygen diffusion barrier. Plant Physiol. 1987 May;84(1):164–172. doi: 10.1104/pp.84.1.164. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Monroe J. D., Owens T. G., Larue T. A. Measurement of the fractional oxygenation of leghemoglobin in intact detached pea nodules by reflectance spectroscopy. Plant Physiol. 1989 Oct;91(2):598–602. doi: 10.1104/pp.91.2.598. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Peterson J. B., Larue T. A. Utilization of aldehydes and alcohols by soybean bacteroids. Plant Physiol. 1981 Aug;68(2):489–493. doi: 10.1104/pp.68.2.489. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Sinclair T. R., Goudriaan J. Physical and morphological constraints on transport in nodules. Plant Physiol. 1981 Jan;67(1):143–145. doi: 10.1104/pp.67.1.143. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Walsh K. B., Vessey J. K., Layzell D. B. Carbohydrate supply and n(2) fixation in soybean : the effect of varied daylength and stem girdling. Plant Physiol. 1987 Sep;85(1):137–144. doi: 10.1104/pp.85.1.137. [DOI] [PMC free article] [PubMed] [Google Scholar]

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

RESOURCES