Larondelle Y, Corbineau F, Dethier M, Come D, Hers H G
Eur J Biochem. 1987 Aug 3;166(3):605-10. doi: 10.1111/j.1432-1033.1987.tb13556.x.
When dormant oat seeds were imbibed at the non-permissive temperature of 30 degrees C, the concentration of phosphoenolpyruvate and of glycerate 3-phosphate, which are two inhibitors of phosphofructokinase 2, increased almost linearly during 30 h. By contrast, these metabolites increased only after a lag period of about 10 h in non-dormant seeds imbibed at the same temperature. As a consequence of this, the concentration of the C3 derivatives remained always remarkably lower in non-dormant than in dormant seeds. Accordingly, the concentration of fructose 2,6-bisphosphate, which increased similarly in the two types of seeds during the first 8 h after the start of inhibition, then reached a plateau in dormant seeds but continued to increase for another 8 h in non-dormant seeds, reaching a maximal value a few hours before the beginning of radicle protrusion. When the dormant seeds were imbibed at the permissive temperature of 10 degrees C, the evolution of all metabolites was slowed down but behaved like that of non-dormant seeds imbibed at 30 degrees C. Experiments in which the dormant seeds were submitted to a jump from 10 degrees C to 30 degrees C and vice versa, always provoked reverse changes in the concentration of the C3 derivatives and of fructose 2,6-bisphosphate, the latter being increased in all conditions that allowed germination. Dormant seeds were also allowed to germinate at 30 degrees C by imbibition during 24 h in the presence of 3% ethanol. Again, this permissive treatment caused an arrest in the accumulation of C3 derivatives and an increase in fructose 2,6-bisphosphate. Another, apparently unrelated, biochemical difference between dormant and non-dormant oat seeds was their inorganic pyrophosphate content, which was approximately five-fold higher in non-dormant than in dormant seeds. This difference was observed before and persisted during imbibition as long as measurement could be made and was not affected by the temperature jumps or by ethanol. In contrast to the phosphoric esters under investigation, pyrophosphate was not preferentially located in the embryo.
当休眠的燕麦种子在30℃的非允许温度下吸水时，磷酸烯醇丙酮酸和3-磷酸甘油酸（这两种磷酸果糖激酶2的抑制剂）的浓度在30小时内几乎呈线性增加。相比之下，在相同温度下吸水的非休眠种子中，这些代谢物仅在约10小时的滞后期后才增加。因此，非休眠种子中C3衍生物的浓度始终显著低于休眠种子。相应地，果糖2,6-二磷酸的浓度在两种类型的种子中，在抑制开始后的前8小时内以相似的方式增加，然后在休眠种子中达到平稳期，但在非休眠种子中继续增加8小时，在胚根突出开始前几小时达到最大值。当休眠种子在10℃的允许温度下吸水时，所有代谢物的变化都减缓了，但表现类似于在30℃下吸水的非休眠种子。将休眠种子从10℃突然转移到30℃或反之的实验，总是会引起C3衍生物和果糖2,6-二磷酸浓度的反向变化，后者在所有允许发芽的条件下都会增加。通过在3%乙醇存在下吸水24小时，休眠种子也能在30℃下发芽。同样，这种允许处理导致C3衍生物积累的停止和果糖2,6-二磷酸的增加。休眠和非休眠燕麦种子之间另一个明显不相关的生化差异是它们的无机焦磷酸含量，非休眠种子中的无机焦磷酸含量比休眠种子高约五倍。这种差异在吸水前就已观察到，并且只要能够进行测量，在吸水过程中就会持续存在，并且不受温度突变或乙醇的影响。与所研究的磷酸酯不同，焦磷酸并非优先位于胚中。
