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REVERSIBLE DEACTIVATION OF NEUROSPORA ASCOSPORES BY LOW TEMPERATURE
Author(s) -
Sun Clare Y.,
Sussman Alfred S.
Publication year - 1960
Publication title -
american journal of botany
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.218
H-Index - 151
eISSN - 1537-2197
pISSN - 0002-9122
DOI - 10.1002/j.1537-2197.1960.tb14910.x
Subject(s) - germination , neurospora , spore , incubation , biology , glycerol , spore germination , botany , dormancy , stimulus (psychology) , horticulture , biochemistry , neurospora crassa , mutant , psychology , psychotherapist , gene
S un, C lare Y., and A lfred S. S ussman. (U. Michigan, Ann Arbor.) Reversible deactivation of Neurospora ascospores by low temperature. Amer. Jour. Bot. 47(7): 589‐593. Illus. 1960.—Heat‐activated ascospores of Neurospora tetrasperma are reversibly deactivated after incubation at 4°C. for 36–48 hr. Two cycles of deactivation and reactivation are possible although the percentage germination decreases in the last cycle. By contrast, spores held at 20°C., or in glycerol at 4°C., will remain activated for much longer periods of time. If an incubation period at 20°C. greater than 30 min. is interposed before the activated spores are placed at 4°C., germination occurs despite the cold‐treatment. Furfural‐activated ascospores, when held at 4°C., are deactivated but can be reactivated only by heat, pointing up a difference between ascospores activated by these different means. Although a fraction of the stimulus afforded by heat‐sensitization to chemical activators is preserved for 2 days at —20°C., it is dissipated completely after a short time at 4°C. These data are discussed on the basis of the suggestion that the reversible production of a substance initiates a series of steps which lead to germination. Thus, the temperature minimum of the forward reaction is greater than 4°C. whereas the back reaction proceeds at this temperature.