Squalene epoxidase catalyzes the oxidation of squalene to 2,3-oxo-squalene (BsSE1), and is the key rate limiting enzyme in the synthesis of triterpenoids and sterols in plants. This study focused on the basic aspects of BsSE1 including the sequence information, sub-cellular localization expression patterns of BsSE1. Using to the sequence information of Bletilla striata transcriptome, the full-length CDs of BsSE1 gene was amplified. The physicochemical properties and structural characteristics of BsSE1 protein were analyzed by bioinformatics analysis software, and vector was constructed to analyze the protein locations and expression patterns. The results showed that the CDS of BsSE1 gene was 1542 bp, encoding 513 amino acids. BsSE1 protein is a hydrophobic protein with two transmembrane domains but no signal peptides. It is localied in the endoplasmic reticulum membrane and belongs to the typical squalene epoxidase gene. BsSE1 has the closest genetic relationship with SE protein of Dendrobium officinale and Phalaenopsis equestris. The expression level of BsSE1 was higher in pseudobulblet of Bletilla striata seedlings, followed by roots, and lower in seedling stems. After SA induction, the expression of BsSE1 in Bletilla striata showed significant changes, increased first, then decreased, finally increase again. The results provide a basis for further study of this gene family in plants.

角鲨烯环氧酶催化角鲨烯氧化为 2,3-氧代角鲨烯 ( BsSE1 )，是植物中三萜类化合物和甾醇合成的关键限速酶。本研究着重于 BsSE1 的基本方面，包括BsSE1的序列信息、亚细胞定位表达模式。利用白芨转录组的序列信息，扩增出BsSE1基因的全长CD 。利用生物信息学分析软件分析BsSE1蛋白的理化性质和结构特征，构建载体分析蛋白定位和表达模式。结果表明，CDSBsSE1基因全长1542 bp，编码513个氨基酸。BsSE1 蛋白是一种疏水性蛋白，具有两个跨膜结构域，但没有信号肽。它定位于内质网膜，属于典型的角鲨烯环氧酶基因。BsSE1与铁皮石斛、蝴蝶兰的SE蛋白亲缘关系最近。BsSE1在白芨幼苗假鳞茎中的表达量较高，其次是根，在幼苗茎中表达量较低。SA诱导后BsSE1在白芨中的表达变化明显，先增加后减少，最后又增加。该结果为进一步研究该基因家族在植物中的应用提供了基础。