Summary
It is suggested that the central strand which traverses plasmodesmata is in open continuity with the endoplasmic reticulum of adjacent cells, and that this strand (desmotubule) represents a modulation of a normal ER membrane so that it comprises solely spherical protein subunits. This concept is used to illustrate how plasmodesmata could form a median nodule or anastomosing central strands. The implications of this model in relation to current theories of symplasmic transport are discussed, and the possibility for further experimental work is outlined.
Article PDF
Similar content being viewed by others
Avoid common mistakes on your manuscript.
References
Anteunis, A., N. Fautrez-Firlefyn etJ. Fautrez, 1967: L'accolement des pronuclei de l'oeuf d'Artemiasalina. J. Ultrastruct. Res.20, 206–210.
Arisz, W. H., 1969: Intercellular polar transport and the role of the plasmodesmata in coleoptiles andVallisneria leaves. Acta. Bot. Neerl.18, 14–38.
Ashworth, C. T., J. S. Leonard, E. H. Eigenbrodt, andF. J. Wrightsman, 1966: Hepatic intracellular osmiophilic droplets. Effect of lipid solvents during tissue preparation. J. Cell Biol.31, 301–318.
Behnke, H.-D., 1966: Cell structures in relation to translocation phenomena in plants. In: Viruses of plants. Amsterdam: North Holland Publishing Company.
Burgess, J., andD. H. Northcote, 1968: The relationship between the endoplasmic reticulum and microtubular aggregation and disaggregation. Planta (Berl.)80, 1–14.
Buvat, R., 1969: Plant cells. London: World University Library.
Clarkson, D. T., A. W.Robards, and J.Sanderson, 1971: The tertiary endodermis in barley roots: fine structure in relation to radial transport of ions and water. Planta (Berl.), in press.
Clowes, F. A. L., andB. E. Juniper, 1968: Plant cells. Oxford and Edinburgh: Blackwell.
Davison, E. M., 1969: Cell to cell movement of tobacco ringspot virus. Virology37, 694–696.
Dolzmann, P., 1965: Elektronenmikroskopische Untersuchungen an den Saughaaren vonTillandsia usneoides. II. Einige Beobachtungen zur Feinstruktur der Plasmodesmen. Planta (Berl.)64, 76–80.
Esau, K., 1967: Anatomy of plant virus infections. Ann. Rev. Phytopathol.5, 45–76.
—, andL. L. Hoeffert, 1967: Relation of beet yellows virus to the phloem and to movement in the sieve tube. J. Cell Biol.32, 71–87.
Falk, H., F. Wunderlich, andW. W. Franke, 1968: Microtubular structures in macronuclei of synchronously dividingTetrahymena pyriformis. J. Protozool.15, 776–780.
Frazer, T. W., andB. E. S. Gunning, 1969: The ultrastructure of plasmodesmata in the flamentous green alga,Bulbochaete hiloensis (Nordst.) Tiffany. Planta (Berl.)88, 244–254.
Frey-Wyssling, A., andK. Mühlethaler, 1965: Ultrastructural plant cytology. Elsevier, Amsterdam.
Glauert, A. M., 1968: Electron microscopy of lipids and membranes. J. roy. micr. Soc.88, 49–70.
Haydon, G. B., 1969: Visualization of substructure in ferritin molecules: an artifact. J. Microscopy89, 251–263.
Helder, R. J., andJ. Boerma, 1969: An electron microscopical study of the plasmodesmata in the roots of young barley seedlings. Acta. Bot. Neerl.18, 99–107.
Jensen, W. A., andR. B. Park, 1967: Cell ultrastructure. Belmont: Wadsworth.
Kollmann, R., undI. Dörr, 1969: Strukturelle Grundlagen des zwischenzelligen Stoffaustausches. Ber. dtsch. bot. Ges.82, 415–425.
—, undW. Schumacher, 1962: Über die Feinstruktur des Phloems vonMetasequoia glyptostroboides und seine jahreszeitlichen Veränderungen. II. Mitt. Vergleichende Untersuchungen der Plasmatischen Verbindungsbrücken in Phloemparenchymzellen und Siebzellen. Planta (Berl.)58, 366–386.
— — 1963: Über die Feinstruktur des Phloems vonMetasequoia glyptostroboides und seine jahreszeitlichen Veränderungen. IV. Mitt. Weitere Beobachtungen zum Feinbau der Plasmabrücken in den Siebzellen. Planta (Berl.)60, 360–389.
Krull, R., 1960: Untersuchungen über den Bau und die Entwicklung der Plasmodesmen im Rindenparenchym vonViscum album. Planta (Berl.)55, 598–629.
Ledbetter, M. C., andK. R. Porter, 1964: Morphology of microtubules of plant cells. Science, N.Y.,144, 872–874.
Lucy, J. A., 1964: Globular lipid micelles and cell membranes. J. theor. Biol.7, 360–373.
Mazia, D., andA. Ruby, 1968: Dissolution of erythrocyte membranes in water and comparison of the membrane protein with other structural proteins. Proc. nat. Acad. Sci.61, 1005–1012.
Newcomb, E. H., 1969: Plant microtubules. Ann. Rev. Pl. Physiol.20, 253–288.
Northcote, D. H., 1968: The organization of the endoplasmic reticulum, the Golgi bodies, and microtubules during cell division and subsequent growth. In: Plant Cell Organelles (J. B. Pridham, ed.). London: Academic Press, 179–197.
O'Brien, T. P., andK. V. Thimann, 1967: Observations on the fine structure of the oat coleoptile. II. The parenchyma cells of the apex. Protoplasma63, 417–442.
Ongun, A., W. W. Thomson, andJ. B. Mudd, 1968: Lipid fixation during preparation of chloroplasts for electron microscopy. J. Lipid Res.9, 417–424.
Robards, A. W., 1968 a: On the Ultrastructure of differentiating secondary xylem in willow. Protoplasma65, 449–464.
— 1968 b: A new interpretation of plasmodesmatal ultrastructure. Planta (Berl.)82, 200–210.
— andP. F. Kidwai, 1969: Cytochemical localization of phosphatase in differentiating secondary vascular cells. Planta (Berl.)87, 227–238.
Robertson, J. D., 1964: Unit membranes: a review with recent new studies of experimental alterations and a new subunit structure in synaptic membranes. In: Cellular membranes in development, 1–81 (M. Locke, ed.). New York: Academic Press.
Tyree, M. T., 1970: The symplast concept. A general theory of symplastic transport according to the thermodynamics of irreversible processes. J. theor. Biol.26, 181–214.
Wooding, F. B. P., 1968: Fine structure of callus phloem inPinus pinea. Planta (Berl.)83, 99–110.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Robards, A.W. The ultrastructure of plasmodesmata. Protoplasma 72, 315–323 (1971). https://doi.org/10.1007/BF01279056
Received:
Revised:
Issue Date:
DOI: https://doi.org/10.1007/BF01279056