AGC1-4 kinase plays a crucial role in the regulation of seeds by mediating cell proliferation and embryo development in Arabidopsis. Seed size is a crucial factor to influence final seed yield in plants. However, the molecular mechanisms that set final seed size still need to be investigated. Here, we identified a novel AGC protein kinase AGC1-4, which encodes a serine-threonine kinase, belongs to the AGC VIIIa subfamily. The seeds of agc1-4 mutant were significantly larger than that in the wild type. Overexpression of the AGC1-4 gene reduced seed size. Regulation of AGC1-4 seed size is dependent on embryonic cell number. To further determine AGC1-4 functions in seed size, we analyzed AGC1-4 phosphoproteins using label-free quantitative phosphoproteomics coupled to the transcriptome of agc1-4 using RNA sequencing (RNA-seq). The RNA-seq analysis showed 1611 differentially expressed genes (DEGs), which cover a wide range of functions, such as cell cycle and embryo development. The 262 unique phosphoproteins were detected by phosphoproteomics analysis. The differentially phosphorylated proteins were involved in cell cycle and post-embryo development. Overlay of the RNA-seq and phosphoproteomics results demonstrated AGC1-4 as an important factor that influences seed size by mediating cell proliferation and embryo development. The results in this study provide novel data on the serine-threonine kinase AGC1-4 mediating seed size in Arabidopsis.

中文翻译：

---

AGC 蛋白激酶 AGC1-4 在拟南芥中介导种子大小。

AGC1-4 激酶通过介导拟南芥中的细胞增殖和胚胎发育在种子调控中起关键作用。种子大小是影响植物最终种子产量的关键因素。然而，仍然需要研究确定最终种子大小的分子机制。在这里，我们鉴定了一种新的 AGC 蛋白激酶 AGC1-4，它编码丝氨酸-苏氨酸激酶，属于 AGC VIIIa 亚家族。agc1-4 突变体的种子明显大于野生型。AGC1-4 基因的过表达减小了种子大小。AGC1-4 种子大小的调节取决于胚胎细胞数。为了进一步确定种子大小中的 AGC1-4 功能，我们使用 RNA 测序 (RNA-seq) 使用与 agc1-4 转录组偶联的无标记定量磷酸蛋白质组学分析了 AGC1-4 磷蛋白。RNA-seq 分析显示了 1611 个差异表达基因 (DEG)，它们涵盖了广泛的功能，例如细胞周期和胚胎发育。通过磷酸蛋白质组学分析检测到 262 种独特的磷蛋白。差异磷酸化的蛋白质参与细胞周期和胚胎后发育。RNA-seq 和磷酸蛋白质组学结果的叠加表明 AGC1-4 是通过介导细胞增殖和胚胎发育影响种子大小的重要因素。本研究的结果提供了关于丝氨酸-苏氨酸激酶 AGC1-4 介导拟南芥种子大小的新数据。差异磷酸化的蛋白质参与细胞周期和胚胎后发育。RNA-seq 和磷酸蛋白质组学结果的叠加表明 AGC1-4 是通过介导细胞增殖和胚胎发育影响种子大小的重要因素。本研究的结果提供了关于丝氨酸-苏氨酸激酶 AGC1-4 介导拟南芥种子大小的新数据。差异磷酸化的蛋白质参与细胞周期和胚胎后发育。RNA-seq 和磷酸蛋白质组学结果的叠加表明 AGC1-4 是通过介导细胞增殖和胚胎发育影响种子大小的重要因素。本研究的结果提供了关于丝氨酸-苏氨酸激酶 AGC1-4 介导拟南芥种子大小的新数据。