Abstract
The polypeptide complement of phloem tissue and xylem tissue in trunks of Pinus sabiniana collected in spring was compared by sodium dodecyl sulphate-polyacrylamide gel electrophoresis. Two polypeptides at 24 and 25 kdalton represented over 20% of the total polypeptide complement of the phloem but were absent in xylem tissue. In an attempt to relate the 24- and 25-kdalton phloem polypeptides (PPP) to cellular constitutents, phloem tissue was fractionated by sequential differential and density-gradient centrifugation utilizing the PPP as biochemical markers. In borate buffer, the fractions containing PPP pelleted at less than 12,000 g and were subsequently enriched in sucrose gradients at densities greater than 1.22. However, the cytological entities containing the PPP were almost completely dissociated when phloem tissue was processed with a 2-amino-2-(hydroxymethyl)-1,3-propanediol (Tris) buffer containing mercaptoethanol, and the PPP were then found in the supernatant of material spun at 45,000 g for 3 h. In electron micrographs of PPP-enriched fractions processed with borate buffer an assortment of structures that are associated with mature sieve cells of pine were found, including filaments, cup-shaped arrays, polyhedral crystals, and paracrystalline bodies. Similar structures were not found in identically processed xylem tissue or in phloem tissue processed with the Tris buffer. It is suggested that the PPP represent a proteinaceous component common to these phloem structures.
Similar content being viewed by others
Abbreviations
- PPP:
-
unique phloem polypeptides
- PVP:
-
polyvinylpyrrolidone
- SDS-PAGE:
-
sodium dodecyl sulphate-polyacrylamide gel electrophoresis
- TM:
-
2-amino-2-(hydroxymethyl)-1,3-propanediol(Tris)-mercaptoethanol
References
Abbe, L., Crafts, A.S. (1939) Phloem of white pine and other coniferous species. Bot. Gaz. (Chicago) 100, 695–722
Alfieri, F.J., Evert, R.F. (1968) Seasonal development of the secondary phloem in Pinus. Am. J. Bot. 55, 518–528
Alosi, M.C. (1980) Morphological and cytological studies on Arceuthobium (Viscaceae) in relationship to host phloem with studies on the healthy phloem in Pinus sabiniana (Pinaceae), pp. 126–212. Ph.D. thesis, Portland State Univ., Portland, Ore., USA
Cronshaw, J. (1975) P-proteins. In: Phloem transport, pp. 79–115, Aronoff, S., Dainty, J., Gorham, P., Srivastava, L., Swanson, E., eds. Plenum Press, New York London
Eschrich, W. (1975) Sealing systems in phloem. In: Encyclopedia of plant physiology, N.S., vol. 1: Transport in plants I. Phloem transport, pp. 39–56, Zimmermann, M.H., Milburn, J.A., eds. Springer, Berlin Heidelberg New York
Eschrich, W., Heyser, W. (1975) Biochemistry of phloem constituents. In: Encyclopedia of plant physiology, N.S., vol. 1: Transport in plants I. Phloem transport, pp. 101–136. Zimmermann, M.H., Milburn, J.A., eds. Springer, Berlin Heidelberg New York
Gaál, Ö., Medgyesi, G.A., Vereczkey, L. (1980) Electrophoresis in the separation of biological macromolecules. John Wiley and Sons, Chichester New York Brisbane Toronto
Kleinig, H. (1975) Biochemistry of phloem proteins. In: Phloem transport, pp. 117–120, Aronoff, S., Dainty, J., Gorham, P., Srivastava, L., Swanson, E., eds. Plenum Press, New York London
Kollmann, R. (1975) Sieve element structure in relation to function. In: Phloem transport, pp. 225–242, Aronoff, S., Dainty, J., Gorham, P., Srivastava, L., Swanson, E., eds. Plenum Press, New York London
Kollmann, R. (1980) Fine structural and biochemical characterization of phloem proteins. Can. J. Bot. 58, 802–806
Laemmli, U.K. (1970) Cleavage of structural proteins during the assembly of the head of bacteriophage T4. Nature (London) 227, 680–685
MacRobbie, E.A.C. (1971) Phloem translocation. Facts and mechanisms: a comparative survey. Biol. Rev. 46, 429–481
Mitchell, R.G. (1967) Abnormal ray tissue in three true firs infested by the balsam woolly aphid. For. Sci. 13, 327–332
Murmanis, L., Evert, R.F. (1966) Some aspects of sieve cell ultrastructure in Pinus strobus. Am. J. Bot. 53, 1065–1078
Neuberger, D.S., Evert, R.F. (1974) Structure and development of the sieve-element protoplast in the hypocotyl of Pinus resinosa. Am. J. Bot. 61, 360–374
Neville, D.M. (1971) Molecular weight determination of protein-dodecyl sulfate complexes by gel electrophoresis in a discontinuous buffer system. J. Biol. Chem. 246, 6328–6334
Parameswaran, N. (1971) Zur Feinstruktur der Assimilaitbahnen in der Nadel von Pinus silvestris. Cytobiologie 3, 70–88
Parthasarathy, M.V. (1974) Ultrastructure of phloem in palms. I. Immature sieve elements and parenchymatic elements. Protoplasma 79, 59–91
Parthasarathy, M.V. (1975) The sieve element structure. In: Encyclopedia of plant physiology, N.S., vol. 1: Transport in plants I. Phloem transport, pp. 3–38, Zimmermann, M.H., Milburn, J.A., eds. Springer, Berlin Heidelberg New York
Sabnis, D.D., Hart, J.W. (1979) Heterogeneity in phloem protein complements from different species. Consequences to hypotheses concerned with P-protein function. Planta 145, 459–466
Sauter, J.J. (1977) Electron microscopical localization of Adenosinetriphosphatase and β-glycerophosphatase in sieve cells of Pinus nigra var. austriaca (Hoess) Badoux. Z. Pflanzenphysiol. 81, 438–458
Sloan, R.T., Sabnis, D.D., Hart, J.W. (1976) The heterogeneity of phloem exudate proteins from different plants: a comparative survey of ten plants using polyacrylamide gel electrophoresis. Planta 132, 97–102
Srivastava, L.M., O'Brien, T.P. (1966) On the ultrastructure of cambium and its vascular derivatives. II. Secondary phloem in Pinus strobus L. Protoplasma 61, 277–293
Weber, K., Osborn, M. (1969) The reliability of molecular weight determinations by dodecyl sulfate-polyacrylamide gel electrophoresis. J. Biol. Chem. 244, 4406–4412
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Alosi, M.C., Park, R.B. Fractionation and polypeptide analysis of phloem tissue of Pinus sabiniana Dougl.. Planta 157, 298–306 (1983). https://doi.org/10.1007/BF00397400
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF00397400