Laboratorium voor Plantenbiochemie, Katholieke Universiteit Leuven, Kardinaal Mercierlaan, 92 B-3030 Heverlee, Belgium.
Proc Natl Acad Sci U S A. 1983 Nov;80(21):6601-5. doi: 10.1073/pnas.80.21.6601.
Induction of germination of Phycomyces blakesleeanus spores by a heat shock and subsequent incubation at 25 degrees C in a glucose- or 6-deoxyglucose-containing culture medium resulted in an intense (20-40 times the initial value) rise in the concentration of fructose 2,6-bisphosphate and hexose 6-phosphates. The increase in the concentration of fructose 2,6-bisphosphate but not that of hexose 6-phosphates was restricted to a 25-min period during which the spores acquired an irreversible capacity to germinate. Incubation of the spores in water for any period of time during this critical period resulted in a parallel decrease in their ability to form hexose phosphates and to germinate. A similar rise in hexose phosphate concentration was also observed when P. blakesleeanus spores were activated by incubation in the presence of acetate and also after induction of germination of other dormant (Neurospora tetrasperma) or nondormant (Mucor racemosus) fungal spores. Extracts of dormant and heat-activated P. blakesleeanus spores contain a fructose, 1,6-bisphosphatase that is inhibited by fructose 2,6-bisphosphate and AMP in a synergistic manner. They also contain a 6-phosphofructo-2-kinase and a fructose-2,6-bisphosphatase.
在含有葡萄糖或 6-脱氧葡萄糖的培养基中，用热休克诱导水霉孢子萌发，并在 25°C 下孵育，导致果糖 2,6-二磷酸和己糖 6-磷酸的浓度强烈升高（初始值的 20-40 倍）。果糖 2,6-二磷酸浓度的增加，但不是己糖 6-磷酸浓度的增加，仅限于孢子获得不可逆萌发能力的 25 分钟期间。在这个关键时期，无论在水中孵育孢子多长时间，都会导致其形成己糖磷酸和萌发的能力平行下降。当 P. blakesleeanus 孢子在存在醋酸盐的情况下孵育或诱导其他休眠（Neurospora tetrasperma）或非休眠（Mucor racemosus）真菌孢子萌发时，也观察到类似的己糖磷酸盐浓度升高。休眠和热激活的 P. blakesleeanus 孢子提取物含有一种果糖 1,6-双磷酸酶，该酶被果糖 2,6-二磷酸和 AMP 以协同方式抑制。它们还含有 6-磷酸果糖 2-激酶和果糖 2,6-二磷酸酶。
