The metabolism and fate of specifically labeled glucose-14C were compared to mannitol-l-14C and arabitol-l-14C during basidiospore germination of Schizophyllum commune on glucose-asparagine minimal broth. Glucose-l-14C metabolism led to more 14C02 evolution than glucose-6-14C in spores and the former activity increased upon germination. Liberation of 14C0 z from glucose-3,4-1aC increased at 8 h to 12 h of germination and exceeded the amount of radioactive 14C0~ released from glucose-l-140. The 1~C02 released from glucose-2-14C increased continually during germination while only minor changes in 14C0~ evolution occurred with glueosc-6-14C. Unlabeled ethanol (0.25 M) inhibited 14C02 evolution with glucose-3,4-1aC and ungerminated spores and this inhibition disappeared upon germination.
More 14C02 was evolved from labeled glucose during germination and less radioactivity became associated with cellular material. Of the latter, alcohol-soluble extracts of spores or gcrmlings contained mainly radioactive trehalose, less mannitol and little or no labeled arabitel, and this decreased upon germination. Germlings also converted more radioactive glucose-14C into KOI{-insoluble material and KOHsoluble components. Spores or gcrmlings converted arabitol-l-14C primarily into trehalose and this was not the case for mannitol-l-l~C.
The nature of cellular control devices operative during fungal spore germination, and hence, cytodifferentiation, represents a fundamental issue in microbial morphogenesis. In pursuit of this problem, attendant morphological alterations and biochemical changes were studied during basidiospore germination in the wood-rotting mushroom Schizophyllum commune. Direct photomicroscopic investigations of live basidiospores undergoing outgrowth, mitosis and subsequent septation revealed important cytological features of germination (~qiederpruem and Jersild, 1972), although most of these localized cellular phenomena remain to be defined in biochemical terms. Additional questions regarding Schizo-19hyllum germination include the significance of the lag period seen in