title: Purification and partial characterization of a beta-glucan fragment that elicits phytoalexin accumulation in soybean.
abstract: The synthesis of phytoalexins (antibiotics) in plant cells is induced by molecules called elicitors. Partial acid hydrolysis of mycelial walls of Phytophthora megasperma f. sp. glycinea solubilized a multicomponent mixture of elicitor-active and elicitor-inactive oligoglucosides. One elicitor-active and seven elicitor-inactive hexa(beta-D-glucopyranosyl)-D-glucitols were purified by gel-filtration, normal-phase partition, and reversed-phase liquid chromatography after reduction with NaBH4. The elicitor-active and all but one of the elicitor-inactive hexa(beta-D-glucopyranosyl)-D-glucitols consisted of 3-, 6-, and 3,6-linked glucopyranosyl residues. The eighth hexa (beta-D-glucopyranosyl)-D-glucitol consisted of beta-4-linked glucopyranosyl residues. The similarity of the structural characteristics of six of the elicitor-inactive hexa(beta-D-glucopyranosyl)-D-glucitols to the elicitor-active hexa(beta-D-glucopyranosyl)-D-glucitol suggested that a highly specific carbohydrate structure was required for elicitor activity.
mesh_terms: D002236:Carbohydrate Conformation; D002850:Chromatography, Gel; D002851:Chromatography, High Pressure Liquid; D005658:Fungi; D005936:Glucans / Q000302:isolation & purification* / Q000494:pharmacology; D010838:Phytophthora; D010936:Plant Extracts; D010940:Plant Proteins / Q000378:metabolism*; D010944:Plants / Q000378:metabolism*; D012717:Sesquiterpenes; D013025:Glycine max; D013729:Terpenes; D000094162:Phytoalexins
chemical_list: D005936:Glucans; D010936:Plant Extracts; D010940:Plant Proteins; D012717:Sesquiterpenes; D013729:Terpenes; D000094162:Phytoalexins