POSTEMBEDMENT LABELING OF INTRACELLULAR CONCANAVALIN A-BINDING SITES IN FREEZE-SUBSTITUTED FUNGAL CELLS

Bourett, T. M., Picollelli, M. A., and Howard, R. J. 1993. Postembedment labeling of intracellular concanavalin A-binding sites in freeze-substituted fungal cells. Experimental Mycology 17, 223-235. We have successfully identified specific intracellular concanavalin A (Con A) binding sites in cells of the fungal rice blast pathogen, Magnaporthe grisea. A postembedding procedure, lectin-gold complex, and freeze-substituted material were used to localize Con A binding within (1) smooth membrane cisternae, (2) the plasmalemma, (3) vesicular and nonvesicular components of the Spitzenkörper exclusive of the core region, (4) the contents of vacuoles distal to the hyphal tip, (5) a population of vesicles in conidia just prior to germination, and (6) the cortical region of cytoplasm in hyphae. These results offer new biochemical information concerning fungal cell physiology, not readily available through other analytical methods, and demonstrate a promising means for the further characterization of the enigmatic endomembrane system in fungi. © 1993 Academic Press. All rights reserved.