Skip to main content
Log in

Structural organization of ultrarapidly frozen barley aleurone cells actively involved in protein secretion

  • Published:
Planta Aims and scope Submit manuscript

Abstract

The ultrastructural organization of actively secreting barley (Hordeum vulgare L. cv. Himalaya) aleurone cells was examined using ultrarapid-freezing (<-10 000°C s-1) followed by freeze-fracture and freeze-substitution. Our analysis indicates that much of the evidence supporting a direct pathway from the endoplasmic reticulum (ER) to the plasma membrane (i.e. bypassing the Golgi apparatus) for the secretion of α-amylase (EC 3.2.1.1) may not be valid. Cryofixed ER cisternae show no sign of vesiculation during active α-amylase secretion in gibberellic acid (GA3)-treated cells. At the same time, Golgi complexes are abundant and numerous small vesicles are associated with the edges of the cisternae. Vesicles appear to be involved in the delivery of secretory products to the plasma membrane since depressions containing excess membrane material appear there. Treatment with GA3 also induces changes in the composition of Golgi membranes; most notably, the density of intramembrane particles increases from 2700 μm-2 to 3800 μm-2 because of an increase of particles in the 3–8.5-nm size range. A slight decrease in 9–11-nm particles also occurs. These changes in membrane structure appear to occur as the Golgi complex becomes committed to the processing and packaging of secretory proteins. We suggest that secretory proteins in this tissue are synthesized in the abundant rough ER, packaged in the Golgi apparatus, and transported to the plasma membrane via Golgi-derived secretory vesicles. Mobilization of reserves is also accompanied by dynamic membrane events. Our micrographs show that the surface monolayer of the lipid bodies fuses with the outer leaflet of the bilayer of protein-body membranes during the mobilization of lipid reserves. Following the breakdown of the protein reserves, the protein bodies assume a variety of configurations.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Similar content being viewed by others

Abbreviations

ER:

endoplasmic reticulum

GA3 :

gibberellic acid

P:

protoplasmic

E:

exoplasmic

References

  • Branton, D.S., Bullivant, S., Gilula, N.G., Karnovsky, M.J., Moor, H., Mühlethaler, K., Northcote, D., Packer, L., Satir, P., Speth, V., Staehelin, L.A., Steere, R.L., Weinstein, R.S. (1975) Freeze-etching nomenclature. Science 190, 54–56

    Google Scholar 

  • Buckhout, T.J., Morré, D.J. (1982) An ultrastructural analysis of aleurone cells: lamellar bodies in aleurone layers of wheat grains during germination. Bot. Gaz. 143, 156–163

    Google Scholar 

  • Buttrose, M. (1971) Ultrastructure of barley aleurone cells as shown by freeze-etching. Planta 96, 13–26

    Google Scholar 

  • Chen, R., Jones, R.L. (1974) Studies on the release of barley aleurone cell proteins: autoradiography. Planta 119, 207–220

    Google Scholar 

  • Chrispeels, M.J. (1976) Biosynthesis, intracellular transport and secretion of extracellular molecules. Annu. Rev. Plant Physiol. 27, 19–38

    Google Scholar 

  • Chrispeels, M.J. (1983) The Golgi apparatus mediates the transport of phytohemagglutinin to the protein bodies in bean cotyledons. Planta 158, 140–151

    Google Scholar 

  • Chrispeels, M.J., Varner, J.E. (1967) Gibberellic acid-enhanced synthesis and release of α-amylase and ribonuclease by isolated barley aleurone layers. Plant Physiol. 42, 398–406

    Google Scholar 

  • Colborne, A.J., Morris, G., Laidman, D.L. (1976) Formation of ER in aleurone cells of germinating wheat: an ultrastructural study. J. Exp. Bot. 27, 759–767

    Google Scholar 

  • Farquhar, M.G., Palade, G.E. (1981) The Golgi apparatus (complex)-(1954–1981)-from artifact to center stage. J. Cell Biol. 91, 77s-103s

    Google Scholar 

  • Firn, R.D. (1975) On the secretion of α-amylase by barley aleurone layers after incubation in gibberellic acid. Planta 125, 227–233

    Google Scholar 

  • Gardiner, M., Chrispeels, M.J. (1975) Involvement of the Golgi apparatus in the synthesis and secretion of hydroxyprolinerich cell wall glycoproteins. Plant Physiol. 55, 536–541

    Google Scholar 

  • Gibson, P.A., Paleg, L.G. (1976) Purification of gibberellic acid-induced lysosomes from wheat aleurone cells. J. Cell Sci. 22, 413–425

    Google Scholar 

  • Gilkey, J., Staehelin, L.A. (1985) Advances in ultrarapid freezing for the preservation of cellular ultrastructure. J. Electron Microsc. Tech., in press

  • Gram, N.H. (1982) The ultrastructure of germinating barley seeds. I. Changes in the scutellum and the aleurone layer in Nordal barley. Carlsberg Res. Commun. 47, 143–162

    Google Scholar 

  • Heuser, J.E., Reese, T.S., Dennis, M.J., Jan, Y., Jan, L., Evans, L. (1979) Synaptic vesicle exocytosis captured by quick freezing and correlated with quantal transmitter release. J. Cell. Biol. 81, 275–300

    Google Scholar 

  • Hooley, R. (1982) Protoplasts isolated from aleurone layers of wild oat (Avena fatua L.) exhibit the classic response to gibberellic acid. Planta 154, 29–40

    Google Scholar 

  • Jacobsen, J.V., Higgins, T.J.V. (1982) Characterization of the α-amylases synthesized by aleurone layers of Himalaya barley in response to gibberellic acid. Plant Physiol. 70, 1647–1653

    Google Scholar 

  • Jacobsen, J.V., Knox, R.B., Pyliotis, N.A. (1971) The structure and composition of aleurone grains in the barley aleurone layer. Planta 101, 189–209

    Google Scholar 

  • Jacobsen, J.V., Zwar, J.A., Chandler, P.M. (1985) Gibberellic-acid-responsive protoplasts from mature aleurone of Himalaya barley. Planta 163, 430–439

    Google Scholar 

  • Johnson, K.D., Chrispeels, M.J. (1973) Regulation of pentosan biosynthesis in barley aleurone tissue by gibberellic acid. Planta 111, 353–364

    Google Scholar 

  • Jones, R.L. (1969a) Gibberellic acid and the fine structure of barley aleurone cells. I. Changes during the lag-phase of α-amylase synthesis. Planta 87, 119–133

    Google Scholar 

  • Jones, R.L. (1969b) Gibberellic acid and the fine structure of barley aleurone cells. II. Changes during synthesis and secretion of α-amylase. Planta 88, 73–86

    Google Scholar 

  • Jones, R.L. (1980) Quantitative and qualitative changes in the endoplasmic reticulum of barley aleurone layers. Planta 150, 70–81

    Google Scholar 

  • Jones, R.L., Carbonell, J. (1984) Regulation of the synthesis of barley aleurone α-amylase by gibberellic acid and calcium ions. Plant Physiol. 76, 213–218

    Google Scholar 

  • Jones, R.L., Chen, P. (1976) Immunohistochemical localization of α-amylase in barley aleurone cells. J. Cell Sci. 20, 183–198

    Google Scholar 

  • Jones, R.L., Jacobsen, J.V. (1982) The role of the endoplasmic reticulum in the synthesis and transport of α-amylase in barley aleurone layers. Planta 156, 421–432

    Google Scholar 

  • Jones, R.L., Jacobsen, J.V. (1983) Calcium regulation of the secretion of α-amylase isoenzymes and other proteins from barley aleurone layers. Planta 158, 1–9

    Google Scholar 

  • Jones, R.L., Price, J.M. (1970) Gibberellic acid and the fine structure of barley aleurone cells. III. Vacuolation of aleurone cells during the phase of ribonuclease release. Planta 94, 191–202

    Google Scholar 

  • Jones, R.L., Varner, J.E. (1967) Bioassay of gibberellins. Planta 72, 155–161

    Google Scholar 

  • Kawasaki, S., Sato, S. (1979) Isolation of the Golgi apparatus from suspension cultured tobacco cells and preliminary observations on the intracellular transport of extensin-precursor. Bot. Mag. (Tokyo) 92, 305–314

    Google Scholar 

  • Locy, R., Kende, H. (1978) The mode of secretion of α-amylase in barley aleurone layers. Planta 143, 89–99

    Google Scholar 

  • Mersey, B., McCully, M.E. (1978) Monitoring of the course of fixation of plant cells. J. Microsc. 114, 49–76

    Google Scholar 

  • Mollenhauer, H.H., Morré, D.J. (1980) The Golgi apparatus. In: The biochemistry of plants, vol. I: The plant cell, pp. 438–489, Tolbert, N.E., ed. Academic Press, New York

    Google Scholar 

  • Morré, D.J., Kartenbeck, J., Franke, W.W. (1979) Membrane flow and interconversions among endomembranes. Biochim. Biophys. Acta 559, 71–152

    Google Scholar 

  • Paleg, L., Hyde, B. (1964) Physiological effects of gibberellic acid. VII. Electron microscopy of barley aleurone cells. Plant Physiol. 39, 673–680

    Google Scholar 

  • Platt-Aloia, K.A., Thomson, W.W. (1982) Freeze-fracture of intact plant tissues. Stain Technol. 57, 327–334

    Google Scholar 

  • Plattner, H., Bachmann, L. (1982) Cryofixation: a tool in biological ultrastructural research. Int. Rev. Cytol. 97, 237–304

    Google Scholar 

  • Roberts, K., Gurney-Smith, M., Hills, G.J. (1972) Structure, composition and morphogenesis of the cell wall of Chlamydomonas reinhardi. I. Ultrastructure and preliminary chemical analysis. J. Ultrastruct. Res. 40, 599–613

    Google Scholar 

  • Rothman, J.E. (1981) The Golgi apparatus: two organelles in tandem. Science 213, 1212–1219

    Google Scholar 

  • Sato, T. (1968) A modified method for lead staining of thin sections. J. Electron Microsc. 17, 158

    Google Scholar 

  • Spurr, A.R. (1969) A low-viscosity epoxy resin embedding medium for electron microscopy. J. Ultrastruct. Res. 26, 31–43

    Google Scholar 

  • Staehelin, L.A. (1976) Reversible particle movements associated with unstacking and restacking of chloroplast membranes. J. Cell Biol. 71, 136–158

    Google Scholar 

  • Staehelin, L.A., Kiermayer, O. (1970) Membrane differentiation in the Golgi complex of Micrasterias denticulata Breb. visualized by freeze-etching. J. Cell Sci. 7, 787–792

    Google Scholar 

  • Swift, J.G., O'Brien, T.P. (1972) The fine structure of the wheat scutellum during germination. Aust. J. Biol. Sci. 25, 469–486

    Google Scholar 

  • Varner, J.E., Ho, D.T. (1976) The role of hormones in the integration of seedling growth. In: The moleular biology of hormone action, pp. 173–194, Papaconstantinou, J., ed. Academic Press, New York London

    Google Scholar 

  • Vigil, E.L., Ruddat, M. (1973) Effect of giberellic acid and actinomycin D on the formation and distribution of rough endoplasmic reticulum in barley aleurone cells. Plant Physiol. 51, 549–558

    Google Scholar 

  • Volkmann, D. (1983) A freeze-fracture study on the differentiation of Golgi and plasma membranes in plant cells. Eur. J. Cell Biol. 30, 258–265

    Google Scholar 

  • Yatsu, L.Y., Jacks, T.J. (1972) Spherosome membranes: half unit-membranes. Plant Physiol. 49, 937–943

    Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Rights and permissions

Reprints and permissions

About this article

Cite this article

Fernandez, D.E., Staehelin, L.A. Structural organization of ultrarapidly frozen barley aleurone cells actively involved in protein secretion. Planta 165, 455–468 (1985). https://doi.org/10.1007/BF00398090

Download citation

  • Received:

  • Accepted:

  • Issue Date:

  • DOI: https://doi.org/10.1007/BF00398090

Key words

Navigation