Summary
Secretory trichomes develop from epidermal cells on the leaf primordia and stem ofPharbitis nil. Following an initial growth phase, trichomes begin active secretion of a protein-carbohydrate mucilage. This mucilage covers the shoot apex and developing leaves ofPharbitis.
The secretory cells possess cellular organelles in forms usually associated with actively secreting cells: many mitochondria, an elaborate network of rough endoplasmic reticulum (RER), many free ribosomes, and numerous dictyosomes. The role of the dictyosomes is twofold: 1. dictyosome vesicles bud coated vesicles which transport materials from the cell and, 2. dictyosome vesicles coalesce, forming large storage vesicles. The storage vesicles are surrounded by, and often in contact with, poculiform RER. The RER forms an interconnected network throughout the cytoplasm, extending from the nuclear envelope to the plasmalemma. Distended profiles of RER are frequently in direct contact with the plasmalemma. Thus, inPharbitis secretory trichomes, it is the coated vesicles and RER which are active in secretion export. These findings imply a secretory pathway which deviates from the usual pattern in glandular cells.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Bonnett, H. T., Jr., 1969: Cortical cell death during lateral root formation. J. Cell Biol.40, 144–159.
—, andE. H. Newcomb, 1966: Coated vesicles and other cytoplasmic components of growing root hairs of radish. Protoplasma62, 59–75.
Bowers, B., 1964: Coated vesicles in the pericardial cells of the Aphid (Myzus persical Sulz). Protoplasma59, 351–367.
Bruni, C., andK. R. Porter, 1965: The fine structure of the parenchymal cell of the normal rat liver. I. General observations. Amer. J. Path.46, 691–755.
Caro, L. G., andG. E. Palade, 1964: Protein synthesis, storage and discharge in the pancreatic exocrine cell: an autoradiographic study. J. Cell Biol.20, 473–495.
Essner, E., andA. B. Novikoff, 1962: Cytological studies on two functional hepatomas. Interrelationships of the endoplasmic reticulum, Golgi apparatus and lysosomes. J. Cell Biol.15, 289–312.
Figier, J., 1969: Incorporation de glycine —3H chez les glandes petiolaires deMercurialis annua L. Planta87, 275–289.
Foster, A. S., 1966: Morphology of anastomoses in the dichotomous venation ofCircaeaster. Amer. J. Bot.53, 588–599.
Friend, D. S., andM. G. Farquhar, 1967: Functions of coated vesicles during protein absorption in the rat vas deferens. J. Cell Biol.35, 357–376.
Horner, H. T., Jr., andN. R. Lersten, 1968: Development, structure and function of secretory trichomes inPsychotria bacteriophila. (Rubiceae). Amer. J. Bot.55, 1089–1099.
Jamieson, J. D., andG. E. Palade, 1967: Intracellular transport of secretory protein in the pancreatic exocrine cell. I. Role of the peripheral elements of the Golgi complex. J. Cell Biol.34, 577–615.
— —, 1968: Intracellular transport of secretory proteins in the pancreatic exocrine cell. IV. Metabolic requirements. J. Cell Biol.39, 589–603.
Jensen, W. A., 1962: Botanical histochemistry. San Francisco: W. H. Freeman and Co.
Lüttge, U., 1971: Structure and function of plant glands. Ann. Rev. Pl. Physiol.22, 23–44.
Mazia, D., P. A. Brewer, andM. Alfert, 1953: The cytochemical staining and measurement of protein with mercuric bromphenol blue. Biol. Bull.104, 57–67.
Mepham, R. H., andG. R. Lane, 1970: Observations on the fine structure of developing microspores ofTradescantia bracteata. Protoplasma70, 1–20.
Morré, O. J., D. D. Jones, andH. H. Mollenhauer, 1967: Golgi apparatus mediated polysaccharide secretion by outer root cap cells ofZea mays. I. Kinetics and secretory pathway. Planta74, 286–301.
Neutra, M., andC. P. LeBlond, 1966: Synthesis of the carbohydrate of mucus in the Golgi complex as shown by electron microscope radioautography of goblet cells from rats injected with glucose —3H. J. Cell Biol.30, 119–134.
Pickett-Heaps, J. D., andD. H. Northcote, 1966: Relationship of cellular organelles to the formation and development of the plant cell wall. J. Exp. Bot.17, 20–26.
Reynolds, E. N., 1963: The use of lead citrate at high pH as an electron-opaque stain. J. Cell Biol.17, 208–212.
Roth, T. F., andK. R. Porter, 1964: Yolk protein uptake in the oocyte of the mosquitoAedes aegypti L. J. Cell Biol.20, 313–332.
Schwab, D. W., E. Simmons, andJ. Scala, 1969: Fine structure changes during function of the digestive gland of Venus's fly trap. Amer. J. Bot.56, 88–100.
Schnepf, E., 1969: Sekretion und Exkretion bei Pflanzen. ProtoplasmatologiaVIII, 8.
Sievers, A., 1963: Beteiligung des Golgi-Apparates bei der Bildung der Zellwand von Wurzelhaaren. Protoplasma56, 188–192.
Spurr, A. R., 1969: A low-viscosity epoxy resin embedding medium for electron microscopy. J. Ultrastruct. Res.26, 31–43.
Stay, B., 1965: Protein uptake in the oocytes of theCecropia moth. J. Cell Biol.26, 46–62.
Thompson, W. W., andL. L. Liu, 1967: Ultrastructural features of the salt gland ofTamarix aphylla L. Planta73, 201–220.
Unzelman, J. M., andP. L. Healey, 1972: Development and histochemistry of nuclear crystals in the secretory trichome ofPharbitis nil. J. Ultrastruct. Res.39, 301–309.
Author information
Authors and Affiliations
Additional information
Predoctoral fellow of National Science Foundation during part of the investigation.
Rights and permissions
About this article
Cite this article
Unzelman, J.M., Healey, P.L. Development, structure, and occurrence of secretory trichomes ofPharbitis . Protoplasma 80, 285–303 (1974). https://doi.org/10.1007/BF01276347
Received:
Revised:
Issue Date:
DOI: https://doi.org/10.1007/BF01276347