Abstract
During early germination, the sporangiospores of Phycomyces blakesleeanus synthesized large amounts of glycerol. Glycerol started leaking out of the spores after some 20 min germination. Simultaneously the water content of the spores greatly increased. Water uptake was accompanied by disapperance of the phase contrast halo and an increase in spore cross-sectional area which all occurred during the same period between 10 and 30 min germination. When spores were incubated in 0.5 or 1 M sucrose, glycerol accumulated in the spores to much higher concentrations and the increase in cellular water content was greatly reduced and retarded. Glycerol synthesis and the concomitant lowering of spore osmotic potential was not the only mediator of spore swelling since equally important glycerol concentrations loaded into dormant spores did not cause spore water uptake or swelling. Also the swelling of the spores was less affected than water uptake by decreases in ambient water potential. Apparently also cell wall loosening was involved in the swelling phenomenon which might have important implications for cellular metabolism.
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References
Adler L, Blomberg A, Nilson A (1985) Glycerol metabolism and osmoregulation in the salt tolerant yeast Debaromyces hansenii. J Bacteriol 162:300–306
Adler L, Pedersen A, Tunblad-Johansson I (1982) Polyol accumulation in two filamentous fungi grown at different concentrations of NaCl. Physiol Plant 56:139–142
Borchert R (1962) Über die Azetataktivierung der Sporangiosporen von Phycomyces blakesleeanus. Beitr Biol Pflanzen 38:31–61
Edgley M, Brown AD (1983) Yeast water relations: physiological changes induced by solute stress in Saccharomyces rouxii. J Gen Microbiol 129:3453–3463
Furch B (1983) Phycomyces spore activation: heat triggered ultrastructural events. Microbios Lett 22:37–49
Furch B, Poltz J, Rudolph H (1976) Lipids of spores from Phycomyces in relation to heat induced germination. Biochem Physiol Pflanzen 169:249–256
Gadd GM, Chudek JA, Foster R, Reed RH (1984) The osmotic responses of Penicillium ochro-chlorum: changes in internal solute levels in response to copper and salt stress. J Gen Microbiol 130:1969–1975
Galle H (1964) Untersuchungen über die Entwicklung von Phycomyces blakesleeanus unter Anwendung des Mikrozeitrafferfilmes. Protoplasma 59:424–471
Pambor L (1978) Development of mitochondria in dormant and germinating sporangiospores of Phycomyces blakesleeanus. Microbios Lett 8:143–153
Pfyffer G, Rast DM (1980) The polyol pattern of some fungi not hitherto investigated for sugar alcohols. Exp Mycol 4:160–170
Pothast K (1978) Influence of water activity on enzymic activity in biological systems. In: Crowe JH, Clegg JS (eds) Dry biological systems, Academic Press, New York, pp 323–342
Rudolph H (1958) Wntwicklungsphysiologische Untersuchungen an den Sporangiophoren von Phycomyces blakesleeanus. Biol Zbl 77:385–437
Rudolph H, Ochsen B (1963) Trehalose-Umsatz wärmeaktivierter Sporen von Phycomyces blakesleeanus. VI. Beitrag zur Kausalanalyse der Wärmeaktivierung von Pilzsporen. Arch Microbiol 65:163–171
Sommer L, Halbsguth W (1957) Grundlegende Versuche zur Keimungsphysiologie von Pilzsporen. Forschungsberichte des Wirtschafts- und Verkehrsministeriums Nordrhein-Westfalen 411:1–85
Van Assche J, Carlier AR, Dekeersmaeker HI (1972) Trehalase activity in dormant and activated spores of Phycomyces blakesleeanus. Planta 103:327–333
Van Laere AJ (1986) Resistance of germinating Phycomyces spores against desiccation, freezing, and acids. FEMS Microbiol Ecol 38:251–256
Van Laere AJ, Hendrix P (1983) Cyclic AMP dependent in vitro activation of trehalase from dormant Phycomyces blakesleeanus spores. J Gen Microbiol 129:3287–3290
Van Laere AJ, Van Assche JA, Carlier AR (1980a) Density changes of Phycomyces spores after reversible and irreversible activation. Arch Microbiol 124:289–291
Van Laere AJ, Van Assche JA, Carlier AR (1980b) Reversible and irreversible activation of Phycomyces blakesleeanus spores. Exp Mycol 4:96–104
Van Laere AJ, Francois A, Overloop K, Verbeke MN, Van Gerven L (1986) Relation between germination trchalose and the status of water as mesured by proton NMR. J Gen Microbiol 133: 239–245
Van Mulders RM, Van Laere AJ (1984) Cyclic AMP, trehalase and germination of Phycomyces blakesleeanus spores. J Gen Microbiol 130:541–547
Van Schaftingen E, Van Laere AJ (1985) Glycerol formation after the breaking of dormancy of Phycomyces blakesleeanus spores. Role of an interconvertible glycerol-3-phosphatase. Eur J Biochem 148:399–404
Verbeke M, Van Laere A (1982) On the role of the spore cell wall in the activation of Phycomyces blakesleeanus spores. Exp Mycol 6:313–320
Verbeke M, Van Laere A (1986) The role of water in the activation of Phycomyces blakesleeanus sporangiospores. Exp Mycol 10:190–195
Wegmann K (1984) Dunaliella, Lebenskünstler der Salzseen. Verhandl Ges Ökologie 12:589–595
Wieland O (1963) Glycerol. In: Bergmever HU (ed) Methods of enzymatic analysis. Academic Press, New York, pp 211–214
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Van Laere, A.J., Hulsmans, E. Water potential, glycerol synthesis, and water content of germinating Phycomyces spores. Arch. Microbiol. 147, 257–262 (1987). https://doi.org/10.1007/BF00463485
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DOI: https://doi.org/10.1007/BF00463485