Protoplasma

, Volume 169, Issue 1, pp 28–41

Substructure of freeze-substituted plasmodesmata

  • B. Ding
  • R. Turgeon
  • M. V. Parthasarathy
Article

DOI: 10.1007/BF01343367

Cite this article as:
Ding, B., Turgeon, R. & Parthasarathy, M.V. Protoplasma (1992) 169: 28. doi:10.1007/BF01343367

Summary

The substructure of plasmodesmata in freeze-substituted tissues of developing leaves of the tobacco plant (Nicotiana tabacum L. var. Maryland Mammoth) was studied by high resolution electron microscopy and computer image enhancement techniques. Both the desmotubule wall and the inner leaflet of the plasmodesmatal plasma membrane are composed of regularly spaced electron-dense particles approximately 3 nm in diameter, presumably proteinaceous and embedded in lipid. The central rod of the desmotubule is also particulate. In plasmodesmata with central cavities, spoke-like extensions are present between the desmotubule and the plasma membrane in the central cavity region. The space between the desmotubule and the plasma membrane appears to be the major pathway for intercellular transport through plasmodesmata. This pathway may be tortuous and its dimensions could be regulated by interactions between desmotubule and plasma membrane particles.

Keywords

Freeze-substitution High-pressure freezing Intercellular transport Nicotiana tabacum Plasmodesmata Propane-jet freezing 

Abbreviations

ER

endoplasmic reticulum

PJF

propane jet freezing

HPF

high pressure freezing

CRT

cathode ray tube

IP3

inositoltrisphosphate

Copyright information

© Springer-Verlag 1992

Authors and Affiliations

  • B. Ding
    • 1
  • R. Turgeon
    • 1
  • M. V. Parthasarathy
    • 1
  1. 1.Section of Plant Biology, Division of Biological SciencesCornell UniversityIthacaUSA
  2. 2.Department of BotanyUniversity of CaliforniaDavisUSA

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