This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via CrossRef Citing Articles via Web of Science (131) Citing Articles via Google Scholar Google Scholar Articles by Ayers, A. R. Articles by Albersheim, P. Search for Related Content PubMed PubMed Citation Articles by Ayers, A. R. Articles by Albersheim, P. Agricola Articles by Ayers, A. R. Articles by Albersheim, P.

Articles

Host-Pathogen Interactions

XI. Composition and Structure of Wall-released Elicitor Fractions ¹

^a Department of Molecular, Cellular and Developmental Biology and Department of Chemistry, University of Colorado, Boulder, Colorado 80302

The structures of the four wall-released elicitor fractions isolated from the Phytophthora megasperma var. sojae mycelial walls have been examined. The results demonstrate that fraction I is primarily composed of a branched -1,3-glucan, similar in structure to the extracellular elicitors described previously (Ayers, A., J. Ebel, F. Finelli, N. Burger, and P. Albersheim. 1976. Plant Physiol. 57: 751-759). Fractions II and IV are primarily composed of a highly branched mannan-containing glycoprotein, with fraction IV richer in protein than fraction II. Fraction III contains, attached to protein, a mixture of the two polysaccharide types found in fraction I and in fractions II and IV. The structural data presented here, in concert with the biological data presented in the previous two papers (Ayers et al. 1976. Plant Physiol. 57: 751-759; 760-765), demonstrate that the only compound produced by P. megasperma var. sojae which contains elicitor activity is the glucan. Evidence is presented that the terminal glycosyl residues of the glucan are required for elicitor activity. In addition, it is demonstrated that 90% of the glucan can be removed enzymically without any loss of biological activity. The active residue of the enzymic digestion is a highly branched 3- and 3,6-linked glucan containing about 4% mannosyl residues. The results presented suggest that the mannosyl residues of the glucan, which represent only about 1% of the undegraded glucan, are likely to participate in the active site of this molecule. The role of elicitors and phytoalexins in host-pathogen interactions is discussed. Evidence for the existence of and possible identity of another factor, which determines race specificity of host-pathogen interactions, is summarized.

³ Present address: Biologie II der Universität, D-78 Freiburg, West Germany.

⁴ To whom reprint requests should be addressed at the Department of Chemistry.

¹ Research was supported by the Energy Research and Development Administration E(11-1)-1426, the Herman Frasch Foundation, New York City, a University of Colorado Faculty Fellowship to P. A., and a Deutsche Forschungsgemeinschaft Fellowship to J. E.

This article has been cited by other articles:

				A. Mithofer and W. Boland Recognition of Herbivory-Associated Molecular Patterns Plant Physiology, March 1, 2008; 146(3): 825 - 831. [Full Text] [PDF]

				J. Fliegmann, A. Mithofer, G. Wanner, and J. Ebel An Ancient Enzyme Domain Hidden in the Putative {beta}-Glucan Elicitor Receptor of Soybean May Play an Active Part in the Perception of Pathogen-associated Molecular Patterns during Broad Host Resistance J. Biol. Chem., January 9, 2004; 279(2): 1132 - 1140. [Abstract] [Full Text] [PDF]

				R. M. BOSTOCK, J. A. KUC, and R. A. LAINE Eicosapentaenoic and Arachidonic Acids from Phytophthora infestans Elicit Fungitoxic Sesquiterpenes in the Potato Science, April 3, 1981; 212(4490): 67 - 69. [Abstract] [PDF]

				B. M. PETERS, D. H. CRIBBS, and D. A. STELZIG Agglutination of Plant Protoplasts by Fungal Cell Wall Glucans Science, July 28, 1978; 201(4353): 364 - 365. [Abstract] [PDF]