Summary
In the outer cap cells of roots of Zea mays, secretion is accompanied by hypertrophy of dictyosome cisternae with formation of large secretory vesicles. Vesicle contents are subsequently released from the protoplast by fusion of the vesicle membrane with the plasma membrane. The secreted material, a highly hydrated polysaccharide, was localized intracellularly by the periodic acid-Schiff reaction. Under appropriate conditions, the product moves outward through the cell wall after discharge from the protoplast, and appears as a droplet adhering to the root tip. Under conditions where the secretory product accumulates at the inner wall surfaces, no external droplet is formed.
The secretory activity has an active phase that is sensitive to metabolic inhibitors and influenced by temperature (Q10>2), and a passive phase that is independent of temperature, insensitive to metabolic inhibitors but sensitive to osmotic agents. The active phase is characterized by a temperature-independent periodicity (3 hours). Sucrose supplied to the growth medium increases the amount of polysaccharide secreted. Polysaccharide synthesis, segregation into vesicles, and discharge from the protoplast are assumed to require active metabolism; the step involving extrusion of polysaccharide through the cell wall region appears to be a passive process influenced by the degree of hydration of the polysaccharide and by cell turgor.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
Literature
Bouck, G. B.: Chromatophore development, pits, and other fine structure in the red alga, Lomentaria Baileyana (Harv.) Farlow. J. Cell Biol. 12, 553–569 (1962).
—: Fine structure and organelle associations in brown algae. J. Cell Biol. 26, 523–538 (1965).
Esau, Katherine: Plant anatomy. New York: Wiley and Sons 1960.
Hall, D., H. H. Mollenhauer, and D. J. Morré: Evidence for secretion of cell dispersing enzymes from maize root cap and epidermis. Proc. Ind. Acad. Sci. 75, 65 (1966).
Humason, G. L.: Animal tissue techniques. San Francisco, London: Freeman 1962.
Jones, D. D., and D. J. Morré: Golgi apparatus mediated polysaccharide secretion by outer root cap cells of Zea mays. II. Isolation and characterization of the secretory product. Z. Pflanzenphysiol. 56, 166–169 (1967).
——, and H. H. Mollenhauer: Glime secretion by outer root cap cells of Zea mays. (Abstr.) Amer. J. Bot. 53, 621 (1966).
Juniper, M. B. E., and R. M. Roberts: Polysaccharide synthesis and the fine structure of root cells. J. Roy. Micr. Soc. 85, 63–72 (1966).
Mollenhauer, H. H.: Plastic embedding mixtures for use in electron microscopy. Stain Technol. 39, 111–114 (1963).
—, and D. J. Morré: Golgi apparatus and plant secretion. Ann. Rev. Plant Physiol. 17, 27–46 (1966a).
——: Tubular connections between dictyosomes and forming secretory vesicles in plant Golgi apparatus. J. Cell Biol. 29, 373–376 (1966b).
—, and W. G. Whaley: An observation on the functioning of the Golgi apparatus. J. Cell Biol. 17, 222–225 (1963).
——, and J. H. Leech: A function of the Golgi apparatus in outer root cap cells. J. Ultrastruct. Res. 5, 193–200 (1961).
Northcote, D. H., and J. D. Pickett-Heaps: A function of the Golgi apparatus in polysaccharide synthesis and transport in the root cap cells of wheat. Biochem. J. 98, 159–168 (1966).
Schnepf, E.: Quantitative Zusammenhänge zwischen der Sekretion des Fangschleimes und den Golgi-Strukturen bei Drosophyllum lusitanicum. Z. Naturforsch. 16b, 605–610 (1961).
—: Zur Cytologie und Physiologie pflanzlicher Drüsen. 1. Über den Fangschleim der Insektivoren. Flora (Jena) 153, 1–22 (1963a).
Schnepf, E.: 2. Über die Wirkung von Sauerstoffentzug und von Atmungsinhibitoren auf die Sekretion des Fangschleimes von Drosophyllum und auf die Feinstruktur der Drüsenzellen. Flora (Jena) 153, 23–48 (1963b).
—: Golgi-Apparat und Sekretbildung in den Drüsenzellen der Schleimgänge von Lamanaria hyperborea. Naturwissenschaften 50, 674–675 (1963c)
Voeller, B. R., M. C. Ledbetter, and K. R. Porter: The plant cell: aspects of its form and function. In: The cell (J. Brachet and A. E. Mirsky, eds.), vol. 6, p. 245–312. New York and London: Acad. Press 1964.
Whaley, W. G., M. Dauwalder, and J. E. Kephart: The Golgi apparatus and an early stage in cell plate formation. J. Ultrastruct. Res. 15, 169–180 (1966).
—, J. E. Kephart, and H. H. Mollenhauer: The dynamics of cytoplasmic membranes during development. In: Cellular Membranes in Development. 22nd Symp. of the Soc. for the Study of Development and Growth (M. Locke, ed.), p. 135–174. New York: Acad. Press 1964.
Author information
Authors and Affiliations
Additional information
Purdue University Agricultural Experiment Station Journal Paper No. 2967; Charles F. Kettering Research Laboratory Contribution No. 261.
Rights and permissions
About this article
Cite this article
James Morré, D., Jones, D.D. & Mollenhauer, H.H. Golgi apparatus mediated polysaccharide secretion by outer root cap cells of Zea mays . Planta 74, 286–301 (1967). https://doi.org/10.1007/BF00384849
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF00384849