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角鲨烯含量是高品质植物食用油评判标准的重要指标之一。鲨烯合酶是角鲨烯合成直接相关的上游调控关键酶。本研究在已构建的油茶种仁转录组数据库基础上,设计特异引物,采用RACE技术获得油茶鲨烯合酶基因的全长cDNA序列,命名为CoSQS(Gen Bank登录号为JX914592)。生物信息学分析结果表明:该序列全长1554 bp,其中含全长的开放阅读框为1245 bp,编码415个氨基酸残基,CoSQS蛋白为弱碱性非分泌型蛋白,具有2个明显的跨膜区和2个角鲨烯和番茄红素合成酶的特异信号区。与柿Dk SQS同源蛋白亲缘关系最近,属于疏水性蛋白。亚细胞定位试验结果显示该基因定位于叶绿体。实时荧光定量PCR分析表明,5-10月间,油茶种仁中CoSQS基因表达量呈现先上升后下降的趋势,转录最高峰在9月下旬。通过关联分析表明CoSQS基因表达量与角鲨烯含量密切相关。
Squalene content is one of the most important indicators of high quality plant edible oil evaluation criteria. Squalene synthase is a key upstream regulator of squalene synthesis. In this study, specific primers were designed based on the constructed transcriptome database of Camellia oleifera seed, and the full-length cDNA sequence of squalene synthase gene was obtained by RACE technology and named CoSQS (Gen Bank accession number JX914592). The results of bioinformatics analysis showed that the full-length open reading frame was 1554 bp, which contained a full-length open reading frame of 1245 bp and encoded 415 amino acid residues. The CoSQS protein was a weakly basic non-secreted protein with two distinct Membrane region and 2 squalene and lycopene synthase specific signal region. It has the closest relationship with persimmon Dk SQS homologous protein and belongs to hydrophobic protein. Subcellular localization test results show that the gene is located in the chloroplast. Real-time quantitative PCR analysis showed that the expression level of CoSQS in Camellia oleifera increased first and then decreased from May to October, with the highest transcription peak in late September. Correlation analysis showed that CoSQS gene expression is closely related to squalene content.