摘　要：丙酮酸激酶（PK）是调控糖酵解途径的关键限速酶，在植物基础物质代谢等生物学过程中起着重要的作用。油莎豆（Cyperus esculentus L.）的块茎富含油脂、淀粉、糖等营养物质，是研究碳代谢及调控机制的一个理想模型。本研究基于转录组分析鉴定出7个油莎豆CePK基因，包括3个质体型CePKp（CePKpα、CePKpβ1和CePKpβ2）和4个细胞质型CePKc（CePKc1、CePKc2、 CePKc3和 CePKc4）。CePK编码的CePK蛋白均具有典型的PK和PK_C结构域，同一类型的CePK蛋白的序列长度、相对分子质量、稳定性和等电点等基本相似。CePKp为亲水蛋白，亚细胞定位预测位于叶绿体。CePKc为稳定的疏水蛋白，亚细胞定位预测位于细胞质。三级结构预测结果显示，CePK均为同源四聚体。在块茎发芽和幼苗建成时期，CePK基因的表达模式具有时空特异性，预示着CePK基因可能差异化调控块茎营养物质的代谢途径。该研究为深入解析油莎豆块茎发芽和幼苗建成的碳流通以及分配等生物学过程协同调控机制和油莎豆高产优质育种提供了新的科学依据。
关键词：油莎豆；丙酮酸激酶；块茎发芽和幼苗建成；碳流通；转录组分析
中图分类号：S565.9                            文献标志码：A                     DOI：10.3969/j.issn.1007-7146.2022.06.008

Abstract: Pyruvate kinase (PK) is a key limited enzyme that regulates the glycolysis pathway, which play an important role in biological process including metabolism of basic substances in plants. Cyperus esculentus L. accumulating high levels of nutrients such as lipid/oil, starch, and sugar in tubers is an ideal model for investigating carbon metabolism and its regulatory mechanisms. A total of 7 CePK genes were identified by mining transcriptome data, including three plastidial CePKp (CePKpα, CePKpβ1 and CePKpβ2) and four cytosolic CePKc (CePKc1, CePKc2, CePKc3 and CePKc4). All CePK proteins encoded by CePK genes have the typical PK and PK_C domains. CePK proteins classified as the same type exhibit the similarity in sequence length, relative molecular weight, stability, and isoelectric point. CePKp proteins are hydrophilic proteins, and predicted to be located in the chloroplast. CePKc proteins are stable hydrophobic proteins, and predicted to be located in the cytoplasm. The tertiary structure prediction indicates that CePK proteins exist in the form of homologous tetramers. During the tuber germination and seedling establishing, the expression patterns of these CePK genes were significantly different, demonstrating that CePK genes may function differentially in regulating nutrient metabolism pathways in the tuber and seedling. The present data provide a new scientific basis for the in-depth analysis of the collaborative regulation mechanism underlying carbon flux and allocation and other biological processes in tuber germination and seedling establishing, as also benefiting breeding of high-yield and high-quality C. esculentus.
Key words: Cyperus esculentus L.; pyruvate kinase; tuber germination and seedling establishing; carbon flux; transcriptome analysis
（Acta Laser Biology Sinica, 2022, 31(6): 533-541）