MICROBIAL ELICITORS AND THEIR RECEPTORS IN PLANTS

Elicitors are molecules that stimulate any of a number of defense resp onses in plants. Research over the past decade has focused on the mech anisms by which plant cells perceive and transduce these biological si gnals to activate defense responses. Of particular interest has been t he identification of specific elicitor-binding proteins that might fun ction as physiological receptors in the signal transduction cascade. T he existence of specific high-affinity binding sites has been demonstr ated far oligosaccharide, glycopeptide, and peptide elicitors, and can didate elicitor-binding proteins have been identified for several of t hem. The properties of these binding sites/proteins are consistent wit h those expected of physiologically important receptors, although expe rimental verification of the role of these binding proteins as recepto rs has not yet been obtained. The purification and characterization of specific elicitor-binding proteins is essential for a detailed unders tanding of the molecular basis for the signal exchange between plant h osts and microbial pathogens that leads to activation of host defenses .