Characterization of the binding of α- l-Fuc (1→2)-β- d-Gal (1→), a xyloglucan signal, in blackberry protoplasts

• Published in: Plant science (Limerick) 2000-02, Vol.151 (2), p.183-192
• Main Authors: Dunand, Christophe, Gautier, Catherine, Chambat, Gérard, Liénart, Yvette
• Format: Article
• Language: English
• Subjects: [α- l-Fuc (1→2)-β- d-Gal (1→)] signal; Biological and medical sciences; Cell biochemistry; Cell physiology; Cell receptors; Cell structures and functions; Fundamental and applied biological sciences. Psychology; Miscellaneous; Molecular and cellular biology; Plant physiology and development; Protoplasts; Rubus fruticosis; Xyloglucan
• ISSN: 0168-9452; 1873-2259
• DOI: 10.1016/S0168-9452(99)00217-4

Previous work showed that the fucose→galactose moiety of the xyloglucan nonasaccharide XXFG is responsable for its biological activity. We used this side chain of XXFG (α- l-Fuc (1→2)-β- d-Gal (1→)) in ligand-binding experiments to demonstrate its role as a signal molecule in plant cells. Proteins solubilized from plasma membrane enriched fractions isolated from Rubus fruticosus protoplasts were tested for their ability to bind the side chain of XXFG, using a digoxigenin- or biotin-conjugated neoglycoprotein specific for 2′-fucosyl-lactose in blots and k-ELISA tests. A putative receptor for the signaling sugar was identified, and the ligand specificity is reported. The role of structural elements important for biological activities was investigated using compounds structurally related to xyloglucan, and a variety of phytohormones such as 2,4-D.