基于转录组测序的铁皮石斛植物甾醇生物合成相关基因分析

Analysis of Related Genes in Phytosterol Biosynthesis in Dendrobium officinale Based on Transcriptome Sequencing Technology

摘要:

为了解铁皮石斛（Dendrobium officinale）植物甾醇的生物合成途径，利用Illumina HiSeq 4000高通量测序技术对茎和叶进行转录组测序，比较植物甾醇生物合成关键酶基因的表达。结果表明，共获得43 085条Unigenes，其中24 459条在Nr、Swiss-prot、KOG和KEGG数据库获得注释，7 333条获得共同注释。KEGG代谢途径分析表明，铁皮石斛植物甾醇生物合成分为3个阶段，共有50个Unigenes（30种酶）参与。表达分析表明，DXR和HMED的表达量明显高于MK和MVD；成熟期茎、叶SMT1的表达量比生长期高，SMT2则生长期高于成熟期；同一时期，SMT1和SMT2在叶的表达量都比茎高。这为铁皮石斛植物甾醇的开发利用和调控植物甾醇生物合成研究提供了科学依据。

Abstract:

In order to understand the biosynthetic pathway of phytosterol in Dendrobium officinale, the transcriptome sequence of stems and leaves at two growth stages was analyzed by using Illumina HiSeq 4000 high-throughput sequencing method, and the expressions of key enzyme genes for phytosterois synthesis were compared. The results showed that a total of 43 085 Unigenes were obtained by transcriptome sequencing, of which 24 459 Unigenes were annotated in Nr, Swiss-prot, KOG and KEGG databases, and 7 333 were commonly annotated. KEGG metabolic pathway analysis showed that phytosterol biosynthesis of D. officinale could be divided into three stages with 50 Unigenes (30 enzymes) involved. The expressions of DXR and HMED were significantly higher in stems and leaves than that of MK and MVD. The expression of SMT1 at mature stage was higher than that at growth stage, while the expression of SMT2 was the opposite. The expressions of SMT1 and SMT2 were higher in leaves than that in stems at the same stage. These would be lay a foundation for the development and utilization of phytosterol and regulating phytosterol biosynthesis in D. officinale.