Department of Plant Science and Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul, Republic of Korea.
Plant Genomics and Breeding Institute, Seoul National University, Seoul, Republic of Korea.
Sci Rep. 2019 Feb 13;9(1):1934. doi: 10.1038/s41598-018-38219-6.
Coumestrol (CMS), a coumestan isoflavone, plays key roles in nodulation through communication with rhizobia, and has been used as phytoestrogens for hormone replacement therapy in humans. Because CMS content is controlled by multiple genetic factors, the genetic basis of CMS biosynthesis has remained unclear. We identified soybean genotypes with consistently high (Daewonkong) or low (SS0903-2B-21-1-2) CMS content over 2 years. We performed RNA sequencing of leaf samples from both genotypes at developmental stage R7, when CMS levels are highest. Within the phenylpropanoid biosynthetic pathway, 41 genes were tightly connected in a functional co-expression gene network; seven of these genes were differentially expressed between two genotypes. We identified 14 candidate genes involved in CMS biosynthesis. Among them, seven were annotated as encoding oxidoreductases that may catalyze the transfer of electrons from daidzein, a precursor of CMS. Two of the other genes, annotated as encoding a MYB domain protein and a MLP-like protein, may increase CMS accumulation in response to stress conditions. Our results will help to complete our understanding of the CMS biosynthetic pathway, and should facilitate development of soybean cultivars with high CMS content that could be used to promote the fitness of plants and human beings.
香豆雌酚（CMS）是一种香豆素异黄酮，在与根瘤菌的通讯中在结瘤中起关键作用，并且已被用作人类激素替代疗法的植物雌激素。由于 CMS 含量受多种遗传因素控制，因此 CMS 生物合成的遗传基础仍不清楚。我们鉴定了两种大豆基因型，它们在两年内具有一致的高（大旺空）或低（SS0903-2B-21-1-2）CMS 含量。我们在 R7 发育阶段对这两种基因型的叶片样本进行了 RNA 测序，此时 CMS 水平最高。在苯丙素生物合成途径中，有 41 个基因紧密连接在一个功能上的共表达基因网络中；其中 7 个基因在两个基因型之间差异表达。我们鉴定了 14 个参与 CMS 生物合成的候选基因。其中，7 个被注释为编码氧化还原酶，可能催化 CMS 的前体大豆黄素中的电子转移。其他两个基因，一个被注释为编码 MYB 结构域蛋白，另一个被注释为 MLP 样蛋白，可能会响应胁迫条件增加 CMS 的积累。我们的研究结果将有助于我们全面了解 CMS 生物合成途径，并有助于开发具有高 CMS 含量的大豆品种，这可以促进植物和人类的适应性。
