Carbohydrates on the surface of urediniospore- and basidiospore-derived infection structures of heteroecious and autoecious rust fungi

Abstract

Nine fluorescein isothiocyanate-labeiled leclins with affinity towards different carbohydrates were used to probe the surface carbohydrates of infection structures in vitro, derived from urediniospores and basidiospores of an autoecious rust species. Uromyces viciae-fabae (Pers,) Schroet., and of a heteroecious rust species, Lhomyces rumicis (Schum,) Wint, Lectin binding was quantified by measuring fluorescence photometrically. All lectins bound in a characteristic pattern to the infection structures of the respective spore types of each rust fungus. Differences were especially obvious between those infection structures normally produced inside leaf tissue, namely the urediniospore-derived substomatal vesicles with infection hyphae, and the basidiospore-derived intraepidermal vesicles. The dikaryotic stage and the monokaryotic stage of the heteroecious fungus differed mainly in their affinity for the lectins from Bandeira simplicifolia and Lotus tetragonolobus. A statistical anaiysis comparing the binding oi the iectins to infection structures of two rust fungi suggested that cell surface composition is determined by nuclear condition. The monokaryotic stages of both rust fungi have a higher degree of similarity than the dikaryotic and monokaryotic stages of the same rust fungus.