Isolation of a receptor for an elicitor of phytoalexins

The induction of phytoalexin biosynthesis in plants in response to oligosaccharide elicitors originating from the mycelial walls of the phytopathogenic fungus Phytophthora megasperma f. sp. glycinea is being used as a model system for the study of cellular signal perception mechanisms in plants. Experiments were designed to identify and purify, from soybean cells, specific binding protein(s) (putative receptors) for a hepta-;Structure-activity studies using a number of chemically synthesized oligosaccharides established that the branched trisaccharide at the nonreducing end of the hepta-;The elicitor-binding sites appeared to be (glyco)proteins integrated in the plant plasma membrane. The elicitor-binding proteins were solubilized from membranes using the non-ionic detergent, n-dodecylsucrose. The detergent-solubilized elicitor-binding proteins retained the ligand-specificity and binding affinity (apparent K...