Appressorium formation in germinating conidia of Magnaporthe grisea was induced on a hydrophilic (noninductive) surface by antifungal compounds. Respiratory inhibitors or un coupling agents such as strobilurins, antimycin A , myxothiazol, rotenone, pterulone A , and oligomycin A were particularly effective whereas sodium cyanide had no effect. Cyclosporin A was effective only at high concentrations. These differentiation-inducing effects were only observed at subfungicidal concentrations at which more than 50% of the germinating conidia formed appressoria. Cycloheximide, nystatin, amphotericin B, and papulacandin A did not induce appressoria. Different strains of M. grisea displayed the same overall response to the inhibitors, varying merely in the percentage of appressoria formed. A combination of the respiratory inhibitors with 2-phenyl-4H -1-benzopyran-4-one (flavone), diphenyleneiodonium (DPI), or salicylhydroxamic acid (SHAM), compounds which interfere with the cyanide-resistant respiration, resulted in a higher sensitivity of the strains towards the respiratory inhibitors, but had no effect on appressorium formation.
A Journal of Biosciences: Zeitschrift für Naturforschung C (ZNC) is an international scientific journal for the emerging field of natural and natural-like products. ZNC publishes original research on the isolation, bio-chemical synthesis and bioactivities of natural products, their biochemistry, pharmacology, biotechnology, and biological activity and innovative developed computational methods for predicting their structure and/or function.