Abstract
When aleurone layers of barley (Hordeum vulgare L.) are incubated with gibberellic acid (GA3) xylose and arabinose—both as free sugars and bound to larger molecules—are released into the medium. Release begins 10–12h after the start of incubation and continues for at least 60h. At the same time there is a GA3-induced breakdown of the cell wall resulting in a loss of 2/3 of the cell-wall pentose during 60h of incubation. GA3 causes the appearance in the medium of an enzyme (or enzymes) which hydrolyze larchwood xylan and aleurone-layer arabinoxylan. Release of the enzyme(s) into the medium begins 28–32h after the start of incubation. Enzyme activity does not accumulate to any large extent in the tissue prior to release into the medium, and is present in very low levels only in the absence of GA3. Xylanase activity is associated with a protein (or proteins) with a molecular weight of 29,000. The hydrolysis of the xylans is largely caused by endoxylanase activity, indicating the importance of endoglycosidases in the GA3-induced breakdown of the aleurone cell wall.
Similar content being viewed by others
References
Albersheim, P., Nevins, D.J., English, P.D., Karr, A.: A method for the analysis of sugars in plant cell wall polysaccharides by gas liquid chromatography. Carbohyd. Res. 5, 340–345 (1967)
Ashford, A.E., Jacobsen, J.V.: Cytochemical localization of phosphatase in barley aleurone cells. The pathway of gibberellic acid-induced enzyme release. Planta [Berl.] 120, 80–105 (1974)
Burke, D., Kaufman, P., McNeil, M., Albersheim, P.: The structure of plant cell walls. VI. A survey of the walls of suspension-cultured monocots. Plant Physiol. 54, 109–115 (1974)
Chrispeels, M.J.: Biosynthesis, intracellular transport, and secretin of extracellular macromolecules. Ann. Rev. Plant Physiol. 27, 19–38 (1976)
Chrispeels, M.J., Tenner, A.J., Johnson, K.D.: Synthesis and release of sucrose by the aleurone layer of barley: Regulation by gibberellic acid. Planta [Berl.] 113, 35–46 (1973)
Chrispeels, M.J., Varner, J.E.: Gibberellic acid-enhanced synthesis and release of α-amylase and ribonuclease by isolated barley aleurone layers. Plant Physiol. 42, 398–406 (1967)
Dische, Z.: Color reaction of carbohydrates. In: Methods in Carbohydrate Chemistry, vol. I, pp. 477–512, Whistler, R.L., Wolfram, M.L., eds. New York: Acad. Press 1962
Johnson, K.D., Chrispeels, M.J.: Regulation of pentosan biosynthesis in barley aleurone tissue by gibberellic acid. Planta [Berl.] 111, 353–364 (1973)
Jones, R.L.: Gibberellic acid and the fine structure of barley aleurone cells. II. Changes during the synthesis and secretion of α-amylase. Planta (Berl.) 88, 73–86 (1969)
Jones, R.L.: Gibberellic acid-enhanced release of β-(1,3)-glucanase from glucanase from barley aleurone cells. Plant Physiol. 47, 412–416 (1971)
Mares, D.J., Stone, B.A.: Studies on wheat endosperm. I. Chemical composition and ultrastructure of the cell walls. Aust. J. biol. Sci. 26, 793–812 (1973)
McNeil, M., Albersheim, P., Taiz, L., Jones, R.L.: The structure of plant cell walls. VII. Barley aleurone cells. Plant Physiol. 55, 64–68 (1975)
Preece, I.A., MacDougal, M.: Enzymatic degradation of cereal hemicelluloses. II. Pattern of pentosan degradation. J. Inst. Brewing 64, 489–500 (1958)
Taiz, L., Honigman, W.A.: Production of cell wall hydrolyzing enzymes by barley aleurone layers in response to gibberellic acid. Plant Physiol. 58, 380–386 (1976)
Taiz, L., Jones, R.L.: Gibberellic acid, β-(1,3)-glucanase and the cell walls of barley aleurone layers. Planta (Berl.) 92, 73–84 (1970)
Taiz, L., Jones, R.L.: Plasmodesmata and an associated cell wall component in barley aleurone tissue. Amer. J. Bot. 60, 67–75 (1973)
Van der Eb, A.A., Nieuwdorp, P.J.: Electron microscopic structure of the aleurone cells of barley during germination. Acta bot. neerl. 15, 690–699 (1967)
Varner, J.E., Ho, D.T.: The role of hormones in the integration of seedling growth. 34th Symp., Soc. Devel. Biol. (in press). New York: Acad. Press (1976)
Varner, J.E., Mense, R.: Characteristics of the process of enzyme release from secretory plant cells. Plant Physiol. 49, 187–189 (1972)
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Dashek, W.V., Chrispeels, M.J. Gibberellic-acid-induced synthesis and release of cell-wall-degrading endoxylanase by isolated aleurone layers of barley. Planta 134, 251–256 (1977). https://doi.org/10.1007/BF00384189
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF00384189