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SOMNUS (SOM)基因编码一个CCCH型锌指蛋白，是PHYTOCHROME INTERACTING FACTO-R3-LIKE5(PIL5)下游的关键负调控因子，参与调控种子的萌发。本研究从十字花科12个物种的全基因组数据库中鉴定了17个SOM基因，其中芸薹属物种白菜、甘蓝和甘蓝型油菜中均包含2个及以上的SOM基因。预测这17个SOM蛋白的等电点和分子量，结果显示LaSOM蛋白明显不同于其他的SOM蛋白。氨基酸序列比对显示LaSOM蛋白缺失了部分氨基酸序列，但所有的SOM蛋白均包含保守的3个锌指基序，其中2个CCCH型的锌指基序。对这些SOM基因的组织结构进行分析，结果显示：只有L aSOM基因存在一个内含子，其他SOM基因均没有内含子，暗示LaSOM基因在进化过程中获得了内含子，并导致LaSOM蛋白缺失部分序列。启动子分析显示每个SOM基因起始密码子上游1000 bp的启动子中至少有2个E-box元件。白菜RNA-seq数据显示BrSOM1在根、茎、叶、花和角果中均不表达，仅在胚胎发育阶段的早期子叶胚和成熟胚中有表达。而BrSOM2在根、茎、叶和花中均有表达，BrSOM2在胚胎发育阶段中的表达类似于BrSOM1，只是在表达水平上比BrSOM1低。研究结果可为深入研究SOM基因奠定基础。“,”SOMNUS (SOM) gene encodes a CCCH-type zinc finger protein, which is a key downstream negative regulator of PHYTOCHROMEINTERACTING FACTOR3-LIKE5 (PIL5) and involves in the regulation of seed germination. This study identified 17 SOM genes from the genomes of 12 Brassicaceae species. Each of Brassica rapa, B. oleracea and B. napus from Brassica had at least 2 SOM genes. Molecular weight (MW) and isoelectric point (pI) of the 17 SOM proteins were predicted by bioinformatics, showing that LaSOM protein was significantly different from the other SOM proteins both in molecular weight and isoelectric point. Amino acid sequence alignment showed that LaSOM protein missed a part of amino acid sequence. However, all of the 17 SOM proteins had three conserved zinc finger motifs, including 2 CCCH-type zinc finger motifs. Gene structure analysis of 17 SOM genes indicated that one intron existed in LaSOM gene, while, no intron was present in the rest SOM genes. The result suggested that the L aSOM gene could gain one intron during the evolutionary process, causing lack of partial amino acid sequence in LaSOM protein. Promoter sequence analysis demonstrated that each SOM gene had at least 2 E-box elements in promoter of 1 000 bp upstream of initiation codon. Based on RNA-seq data of B. rapa, BrSOM1 was not expressed in roots, stems, leaves, flowers and siliques, but in early cotyledon embryo and mature embryo of the embryonic stage. However, BrSOM2 was expressed in roots, stems, leaves and flowers. In embryonic development, the expression profile of BrSOM2 was similar to that of BrSOM1, while, BrSOM2 showed lower expression level than BrSOM1. The results can lay the foundation for further research on SOM genes.