Skip to main content
Plant Physiology logoLink to Plant Physiology
. 1992 Dec;100(4):1962–1967. doi: 10.1104/pp.100.4.1962

Effects of Deuterium Oxide on Growth, Proton Extrusion, Potassium Influx, and in Vitro Plasma Membrane Activities in Maize Root Segments 1

Gian Attilio Sacchi 1, Maurizio Cocucci 1
PMCID: PMC1075891  PMID: 16653224

Abstract

Elongation of subapical segments of maize (Zea mays) roots was greatly inhibited by 2H2O in the incubation medium. Short-term exposure (30 min) to 2H2O slightly reduced O2 uptake and significantly increased ATP levels. 2H2O inhibited H+ extrusion in the presence of both low (0.05 mm) and high (5 mm) external concentrations of K+ (about 30 and 53%, respectively at 50% [v/v] 2H2O). Experiments on plasma membrane vesicles showed that H+-pumping and ATPase activities were greatly inhibited by 2H2O (about 35% at 50% [v/v] 2H2O); NADH-ferricyanide reductase and 1,3-β-glucan synthase activities were inhibited to a lesser extent (less than 15%). ATPase activities present in both the tonoplast-enriched and submitochondrial particle preparations were not affected by 2H2O. Therefore, the effect of short incubation time and low concentration of 2H2O is not due to a general action on overall cell metabolism but involves a specific inhibition of the plasma membrane H+ -ATPase. K+ uptake was inhibited by 2H2O only when K+ was present at a low (0.05 mm) external concentration where absorption is against its electrochemical potential. The transmembrane electric potential difference (Em) was slightly hyperpolarized by 2H2O at low K+, but was not affected at the higher K+ concentrations. These results suggest a relationship between H+ extrusion and K+ uptake at low K+ external concentration.

Full text

PDF

Selected References

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

  1. Boudet A., Humphrey T. J., Davies D. D. The measurement of protein turnover by density labelling. Biochem J. 1975 Nov;152(2):409–416. doi: 10.1042/bj1520409. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Cocucci M., Davies D. D. The separation of proteins based on their age, for the study of protein degradation in Escherichia coli. J Gen Microbiol. 1983 Aug;129(8):2509–2519. doi: 10.1099/00221287-129-8-2509. [DOI] [PubMed] [Google Scholar]
  3. Epstein E., Rains D. W., Elzam O. E. RESOLUTION OF DUAL MECHANISMS OF POTASSIUM ABSORPTION BY BARLEY ROOTS. Proc Natl Acad Sci U S A. 1963 May;49(5):684–692. doi: 10.1073/pnas.49.5.684. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Humphrey T. J., Davies D. D. A sensitive method for measuring protein turnover based on the measurement of 2-3H-labelled amino acids in protein. Biochem J. 1976 Jun 15;156(3):561–568. doi: 10.1042/bj1560561. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Kochian L. V., Lucas W. J. Potassium transport in corn roots : I. Resolution of kinetics into a saturable and linear component. Plant Physiol. 1982 Dec;70(6):1723–1731. doi: 10.1104/pp.70.6.1723. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Kochian L. V., Shaff J. E., Lucas W. J. High affinity k uptake in maize roots: a lack of coupling with h efflux. Plant Physiol. 1989 Nov;91(3):1202–1211. doi: 10.1104/pp.91.3.1202. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. Ladror U. S., Zielinski R. E. Protein kinase activities in tonoplast and plasmalemma membranes from corn roots. Plant Physiol. 1989 Jan;89(1):151–158. doi: 10.1104/pp.89.1.151. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. Palmgren M. G., Askerlund P., Fredrikson K., Widell S., Sommarin M., Larsson C. Sealed inside-out and right-side-out plasma membrane vesicles : optimal conditions for formation and separation. Plant Physiol. 1990 Apr;92(4):871–880. doi: 10.1104/pp.92.4.871. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. Rodriguez-Navarro A., Blatt M. R., Slayman C. L. A potassium-proton symport in Neurospora crassa. J Gen Physiol. 1986 May;87(5):649–674. doi: 10.1085/jgp.87.5.649. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. Sussman M. R., Harper J. F. Molecular biology of the plasma membrane of higher plants. Plant Cell. 1989 Oct;1(10):953–960. doi: 10.1105/tpc.1.10.953. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. Villalobo A. Potassium transport coupled to ATP hydrolysis in reconstituted proteoliposomes of yeast plasma membrane ATPase. J Biol Chem. 1982 Feb 25;257(4):1824–1828. [PubMed] [Google Scholar]

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

RESOURCES