Maize (Zea mays L.) is a major dietary source of human caloric intake. Grain filling, the developmental stage of the seed during which starch and proteins accumulate, is of great interest in plant biology and agronomy. However, proteomic datasets covering maize seed development, especially during grain filling, are much scarcer than transcriptomic datasets, largely due to the labor-intensive and costly nature of the large-scale analysis required for proteomics. Here, we searched for proteins that showed changes in abundance during four time-points covering the middle stages of grain filling by two-dimensional electrophoresis, MALDI-TOF, and database searches. We detected 1384 protein spots, of which 48 exhibited differential accumulation during grain filling. Of those, we identified the underlying protein for 32 spots: they included enzymes of carbohydrate metabolism, stress-related proteins, and storage proteins, the latter of which represented 34% of all changing proteins during grain filling. Proteins related to carbohydrate metabolism reached their maximum accumulation around 15–20 days after pollination (DAP) and subsequently dropped until 30 DAP. The rise of stress-related proteins such as heat shock proteins demonstrated their involvement in grain filling and seed maturation. This study catalogues the proteome changes during grain filling and provides basic but critical information regarding the biological changes during maize kernel development.

中文翻译：

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糖酵解刺激和贮藏蛋白积累是玉米（Zea mays L.）籽粒灌浆的标志

玉米（Zea mays L.）是人类热量摄入的主要饮食来源。谷物填充是淀粉和蛋白质在其中积累的种子的发育阶段，在植物生物学和农学中引起了极大的兴趣。但是，蛋白质组学数据集涵盖了玉米种子的发育，尤其是在灌浆过程中，比转录组数据集要稀缺得多，这在很大程度上是因为蛋白质组学所需的大规模分析的劳动强度大且成本高。在这里，我们通过二维电泳，MALDI-TOF和数据库搜索来搜索在四个时间点内显示丰度变化的蛋白质，这些时间点涵盖了谷物填充的中间阶段。我们检测到1384个蛋白斑点，其中48个在灌浆过程中表现出差异积累。其中，我们确定了32个斑点的潜在蛋白质：它们包括碳水化合物代谢的酶，与压力有关的蛋白质和储藏蛋白质，其中后者占谷物填充过程中所有变化的蛋白质的34％。与碳水化合物代谢有关的蛋白质在授粉（DAP）后约15–20天达到最大积累，随后下降直至30 DAP。诸如热激蛋白等与压力相关的蛋白的出现表明它们参与了籽粒的填充和种子的成熟。这项研究对谷物填充过程中蛋白质组的变化进行了分类，并提供了有关玉米粒发育过程中生物学变化的基本但至关重要的信息。与碳水化合物代谢有关的蛋白质在授粉（DAP）后约15–20天达到最大积累，随后下降至30 DAP。诸如热激蛋白等与压力相关的蛋白的出现表明它们参与了籽粒的填充和种子的成熟。这项研究对谷物填充过程中蛋白质组的变化进行了分类，并提供了有关玉米粒发育过程中生物学变化的基本但至关重要的信息。与碳水化合物代谢有关的蛋白质在授粉（DAP）后约15–20天达到最大积累，随后下降至30 DAP。诸如热激蛋白等与压力相关的蛋白的出现表明它们参与了籽粒的填充和种子的成熟。这项研究对谷物填充过程中蛋白质组的变化进行了分类，并提供了有关玉米粒发育过程中生物学变化的基本但至关重要的信息。