The inverse correlation between protein and oil production in soybeans is well-documented; however, it has been based primarily on the composition of mature seeds. Though this is the cumulative result of events over the course of soybean seed development, it does not convey information specific to metabolic fluctuations during developmental growth regimes. Maternal nutrient supply via seed coat exudate measurements and metabolite levels within the cotyledon were assessed across development to identify trends in the accumulation of central carbon and nitrogen metabolic intermediates. Active metabolic operation during late seed development was probed through transient labeling with 13C substrates. The results indicated: i) a drop in lipid during seed maturation with a concomitant increase in carbohydrates, ii) a transition from seed filling to maturation phase characterized by quantitatively balanced changes in the carbon use and CO2 release, iii) changes in measured carbon and nitrogen resources supplied maternally over development, iv) 13C metabolites processed through gluconeogenesis towards sustained carbohydrate accumulation as the maternal nutrient supply diminishes, and v) oligosaccharide biosynthetic metabolism during seed coat senescence at maturation. These results highlight temporal engineering targets for altering final biomass composition to increase the value of soybeans and a path to breaking the inverse seed protein and oil correlation.

中文翻译：

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种子发育后期代谢的时间变化会影响大豆的生物量组成

大豆中蛋白质与油脂产量之间的负相关关系得到了充分证明。但是，它主要基于成熟种子的组成。尽管这是大豆种子发育过程中事件累积的结果，但它并未传达发育过程中代谢波动所特有的信息。在整个发育过程中评估通过种皮分泌物测量和子叶内代谢产物水平进行的母体营养供应，以确定中央碳和氮代谢中间产物积累的趋势。通过用13 C底物进行瞬时标记，探索了种子后期发育过程中的主动代谢操作。结果表明：i）种子成熟过程中脂质下降，同时碳水化合物增加，ii）从种子填充到成熟阶段的过渡，其特征在于碳使用量和CO2释放量的定量平衡变化； iii）在发育过程中由母体提供的测得的碳和氮资源的变化； iv）通过糖异生作用加工的13C代谢物作为碳水化合物的持续积累。母体营养供应减少，v）成熟时种皮衰老过程中寡糖的生物合成代谢。这些结果突出了用于改变最终生物量组成以增加大豆价值的暂时性工程目标，以及打破逆向种子蛋白质与油脂相关性的途径。iv）随着母体营养供应的减少，通过糖异生作用向持续的碳水化合物积累加工的13C代谢物，以及v）在种皮衰老过程中成熟时寡糖的生物合成代谢。这些结果突出了用于改变最终生物量组成以增加大豆价值的暂时性工程目标，以及打破逆向种子蛋白质与油脂相关性的途径。iv）随着母体营养供应的减少，通过糖异生作用向持续的碳水化合物积累加工的13C代谢物，以及v）在种皮衰老过程中成熟时的寡糖生物合成代谢。这些结果突出了用于改变最终生物量组成以增加大豆价值的暂时性工程目标，以及打破逆向种子蛋白质与油脂相关性的途径。