Alterations of Vessel Elements and Reactions of Surrounding Tissues in the DED Syndrome

  • G. B. Ouellette
  • Danny Rioux


A summary of the principal observations accumulated by the senior author and colleagues since 1970, concerning the histopathology of DED, is presented. An overview of events occurring in disease development are exposed such as: invasion of secondary vessel elements and accumulation therein of extraneous material (including the alveolar network), attack of vessel walls (in association with masses of electron opaque material) and surrounding tissues up to the cambial area, pathogen action on proto- and metaxylem tissues, and similar observations of differentiating tissues, where cell malformation is often pronounced. Various types of cytoplasmic reactions in the axial parenchyma of secondary xylem, are mentioned. Some of these, considered detrimental, range from a high vacuolization of the cytoplasm, of pronounced organelle alterations up to complete cytoplasmic disintegration; other reactions may be considered of a defense type: increased opacity and density of the cytoplasm, accumulation of large amounts of opaque or more translucent matter in large vacuoles, and so on. These are ordinarily accompanied by wall modifications, such as an increased density and opacity of the protective layer. Intermediate situations exist. Wall modifications in parenchyma cells and fibers in normal wood or in barrier zones are thought to be associated with trees showing some degree of resistance or having partially recovered from acute symptoms. As a corollary, susceptibility can be associated with a lack of such reactions, particularly in shoot and twigs where tissue disturbances seem to be most prominent. It is stressed that all the disturbances observed are associated with the presence of masses or strands of opaque matter. These observations point to the necessity of characterizing further these opaque constituents, or at least recognizing that a problem exists that calls for the formulation of new concepts.


Secondary Wall Secondary Xylem Vessel Element Wall Ingrowth Opaque Material 
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  1. Baayen, R.P. 1988. Fusarium wilt of carnation. Disease development, resistance mechanisms of the host and taxonomy of the pathogen. Ph. D. thesis, Univ. Amsterdam, 165 pp.Google Scholar
  2. Benhamou, N., Chamberland, H., Ouellette, G.B., and Pauze, F.J. 1987. Ultrastructural localization of B-(1→4)-D-glucans in two pathogenic fungi and in their host tissues by means of an exoglucanase-gold complex. Can. J. Microbiol. 33:405–417.CrossRefGoogle Scholar
  3. Harling, R., and Taylor, G.S. 1985. A light microscope study of resistant and susceptible carnations infected with Fusarium oxysporum f. sp. dianthi. Can. J. Bot. 63: 638–646.CrossRefGoogle Scholar
  4. Ouellette, G.B. 1978a. Ultrastructural observations on pit membrane alterations and associated effects in elm xylem tissues infected by Ceratocystis ulmi. Can. J. Bot. 56:2567–2588.CrossRefGoogle Scholar
  5. Ouellette, G.B. 1978b. Light and electron microscopic studies on cell wall breakdown in American elm xylem tissues infected with Dutch elm disease. Can. J. Bot. 56:2666–2693.CrossRefGoogle Scholar
  6. Ouellette, G.B. 1981a. Ultrastructural cell wall modifications in secondary xylem of American elm surviving the acute stage of Dutch elm disease: vessel members. Can. J. Bot. 59:2411–2424.CrossRefGoogle Scholar
  7. Ouellette, G.B. 1981b. Ultrastructural cell wall modifications in secondary xylem of American elm surviving the acute stage of Dutch elm disease: fibres. Can. J. Bot. 59:2425–2438.CrossRefGoogle Scholar
  8. Ouellette, G.B. 1982. Comparative ultrastructural observations of reactions of xylem parenchyma cells to Ceratocystis ulmi infection in Ulmus spp. Pages 267–297 in Proceedings of Dutch elm disease symposium and workshop, Winnipeg, Man., October 5–9, 1981. E.S. Kondo, Y. Hiratsuka, and W.B.G. Denyer, eds.Google Scholar
  9. Ouellette, G.B., and Rioux, D. 1992. Anatomical and physiological aspects of resistance to Dutch elm disease. In Defense mechanisms of woody plants against fungi. R. A. Blanchette and A. R. Biggs, eds., Springer-Verlag, New York. (In Press).Google Scholar
  10. Pennypacker, B.W., and Nelson, P.E. 1972. Histopathology of carnation infected with Fusarium oxysporum f sp. dianthi. Phytopathology 62:1318–1326.CrossRefGoogle Scholar
  11. Rioux, D., and Ouellette, G. B. 1989. Light microscope observations of histological changes induced by Ophiostoma ulmi in various nonhost trees and shrubs. Can. J. Bot. 67:2335–2351.CrossRefGoogle Scholar
  12. Rioux, D., and Ouellette, G. B. 1991a. Barrier zone fonnation in host and nonhost trees inoculated with Ophiostoma ulmi. I. Anatomy and histochemistry. Can. J. Bot. 69:2055–2073.CrossRefGoogle Scholar
  13. Rioux, D., and Ouellette, G. B. 1991b. Barrier zone formation in host and nonhost trees inoculated with Ophiostoma ulmi. II. Ultrastructure. Can. J. Bot. 2074–2083.Google Scholar
  14. Shi, J., Mueller, W.C. and Beckman, C.H. 1992. Vessel occlusion and secretory activities of vessel contact cells in resistant or susceptible cotton plants infected with Fusarium oxysporum f. sp. vasinfectum. Physiol. Mol. Plant Pathol. 40:133–147.CrossRefGoogle Scholar
  15. Shigo, A.L., and Marx, H.G. 1977. Compartmentalization of decay in trees. USDA Forest Service, Washington, DC.Google Scholar

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© Springer-Verlag New York, Inc. 1993

Authors and Affiliations

  • G. B. Ouellette
  • Danny Rioux

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