ENZYME ACTIVITIES DURING THE ASEXUAL CYCLE OF NEUROSPORA CRASSA: I. SUCCINIC DEHYDROGENASE

Abstract

Separate extracts of Neuorospora crassa grown either in Vogel's medium N, medium N + glutamate, or medium N which had been made deficient in zinc, were assayed for succinic dehydrogenase and soluble protein at intervals throughout the asexual cycle. Succinic dehydrogenase, although apparently unnecessary for either the formation of conidia or conidial germination, does appear to be necessary for mycelial growth and for the production of conidiophores. Differences in the amount of enzyme during morphologically distinct states of differentiation (i.e. production of the germ tube and production of the conidiophore) may serve as an indicator of significant changes in the physiology of Neurospora at these times during development.The level of succinic dehydrogenase in the conidiophore before its differentiation into conidia appears to influence the amount of this enzyme found in the conidia. This is in keeping with the idea that conditions prevailing in the cytoplasm before the formation of conidia may directly influence the constituents subsequently found in the conidia which determine conidial viability, rate of germination, and growth yield.