Plant and Soil

, Volume 241, Issue 1, pp 11–17

Localization of the plasma membrane H+-ATPase in Fe-deficient cucumber roots by immunodetection

  • Marta Dell'Orto
  • Livia Pirovano
  • José Manuel Villalba
  • José Antonio González-Reyes
  • Graziano Zocchi

Abstract

As in several Strategy I plants, iron-deficiency induces in cucumber (Cucumis sativus L.) roots a strong increase in the PM (plasma membrane) H+-ATPase activity with a consequent acidification of the rhizosphere. This increase is mainly due to enhanced synthesis of the enzyme even though other regulatory mechanisms have not yet been ruled out. As it was found in many other dicot species, in Fe-deficient cucumber roots we found a strong development of short lateral roots and swollen root tips; furthermore an enhanced H+ extrusion was particularly confined to the subapical swollen zone. Analysis of the root tissue structure by optical and electron microscopy showed a strong proliferation of root hairs at the subapical level and some ultrastructural modifications in the external layers. The structural localization of the PM H+-ATPase studied by immunohistochemistry showed that the increase of the PM protein is not simply due to a greater number of root tips in Fe-deficient plants but also to an increased enzyme content in each tip; moreover, the enhanced H+ extrusion seems to be functionally coupled to the root hairs formation. Northern analysis of PM H+-ATPase mRNA extracted from apical root segments using a cDNA probe specific for the PM H+-ATPase of cucumber roots suggests that the modulation of the enzyme synthesis occurs at the transcriptional level.

immunolocalization iron-deficiency PM H+-ATPase proton extrusion rhizosphere acidification root hairs 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. Dell'Orto M, Santi S, De Nisi P, Cesco S, Varanini Z, Zocchi G and Pinton R 2000 Development of Fe deficiency responses in cucumber (Cucumis sativus L.) roots: involvement of plasma membrane H+-ATPase activity. J. Exp. Bot. 51, 695-701.Google Scholar
  2. Kramer D, Römheld V, Landsberg E C and Marschner H 1980 Induction of transfer-cell formation by iron deficiency in the root epidermis of Helianthus annuus L. Planta 147, 335-339.Google Scholar
  3. Landsberg E C 1982 Transfer cell formation in the root epidermis: a prerequisite for iron efficiency? J. Plant. Nutr. 75, 415-432.Google Scholar
  4. Landsberg E C 1984 Regulation of iron-stress response by wholeplant activity. J. Plant. Nutr. 7, 609-621.Google Scholar
  5. Landsberg E C 1986 Function of rhizodermal transfer cells in the Fe stress response mechanism of Capsicum annuum L. Plant Physiol. 82, 511-517.Google Scholar
  6. Landsberg E C 1989 Proton efflux and transfer cell formation as response to Fe deficiency of soybean in nutrient solution culture. Plant Soil 114, 53-61.Google Scholar
  7. Landsberg E C 1994 Transfer cell formation in sugar beet roots induced by latent Fe deficiency. Plant Soil 165, 197-205.Google Scholar
  8. Marschner H and Römheld V 1981 Iron deficiency stress induced morphological and physiological changes in root tips of sunflower. Physiol Plant. 53, 354-360.Google Scholar
  9. Marschner H, Römheld V and Ossenberg-Neuhaus H 1982 Rapid method for measuring changes in pH and reducing processes along roots of intact plants. Z. Pflanzenphysiol 105, 407-416.Google Scholar
  10. Moog P, Van Der Kooij T A W, Brüggemann W, Schiefelbein J W and Kuiper P J C 1995 Responses to iron deficiency in Arabidopsis thaliana: The turbo iron reductase does not depend on the formation of root hairs and transfer cells. Planta 195, 505-513.Google Scholar
  11. Parets-Soler A, Pardo J M and Serrano R 1990 Immunocytolocalization of plasma-membrane H+-ATPase. Plant Physiol. 93, 1654-1658.Google Scholar
  12. Rabotti G and Zocchi G 1994 Plasma membrane-bound H+-ATPase and reductase activities in Fe-deficient cucumber roots. Physiol. Plant. 90, 779-785.Google Scholar
  13. Roland J C 1978 General preparation and staining of thin section. In Electron Microscopy and Cytochemistry of Plant Cells. Ed. JL Hall. pp 1-63. Elsevier-North Holland Bio-Medica Press, Amsterdam.Google Scholar
  14. Römheld V and Kramer D 1983 Relationship between proton efflux and rhizodermal transfer cells induced by iron deficiency. Z Pflanzenphysiol 113, 73-83.Google Scholar
  15. Römheld V and Marschner H 1981 Iron deficiency stress induced morphological and physiological changes in root tips of sunflower. Physiol. Plant. 53, 354-360.Google Scholar
  16. SchmidtWand Bartles M 1996 Formation of root epidermal transfer cells in Plantago. Plant Physiol. 110, 217-225.Google Scholar
  17. Villalba J M, Lützelschwab M and Serrano R 1991 Immunocytolocalization of plasma-membrane H+-ATPase in maize coleoptiles and enclosed leaves. Planta 185, 458-461.Google Scholar
  18. Zocchi G and Cocucci S 1990 Fe uptake mechanism in Fe-efficient cucumber roots. Plant Physiol. 92, 908-911.Google Scholar

Copyright information

© Kluwer Academic Publishers 2002

Authors and Affiliations

  • Marta Dell'Orto
    • 1
  • Livia Pirovano
    • 1
  • José Manuel Villalba
    • 2
  • José Antonio González-Reyes
    • 2
  • Graziano Zocchi
    • 1
  1. 1.Dipartimento di Produzione VegetaleUniversity of MilanoMilanoItaly
  2. 2.Departamento de Biología Celular, Fisiología e ImmunologíaUniversity of CórdobaCórdobaSpain

Personalised recommendations