珍稀药用植物珠子参的转录组测序及分析

Transcriptome profiling and analysis of Panax japonicus var. major

药用植物珠子参的根茎在中国西南区域已有上千年的药用历史,三萜皂苷为珠子参最主要的活性成分。为了探索珠子参根茎中皂苷物质生物合成的分子基础,该文采用Illumina Hi Seq 2000高通量测序获得珠子参根茎的转录组数据;使用Trinity和TGICL软件实现Unigene的de novo拼接;基于BLAST完成Unigene的蛋白功能注释、KOG功能注释、GO分类和KEGG代谢通路分析。最终获得了短读序15.6 Gb,通过de novo拼接注释得到Unigene 62 240个。研究发现,珠子参根茎部表达的19个Unigene与三萜碳环骨架合成相关;69个Unigene与介导三萜碳环骨架的氧化和羟基化等修饰的CYP450相关,18个Unigene与负责三萜碳环骨架的糖基化的糖基化转移酶相关。该研究发现的三萜皂苷合成相关候选基因对于阐明珠子参三萜皂苷合成方式研究提供了重要的基础。

The rhizome of Panax japonicus var. major have been used as the natural medicinal agent by Chinese traditional doctors for more than thousand years. Most of the therapeutic effects of P. japonicus var. major had been reported due to the presence of tetracyclic or pentacyclic triterpene saponins. In this study, Illumina pair-end RNA-sequencing and de novo splicing were done in order to understand the pathway of triterpenoid saponins in this species. The valid reads data of 15.6 Gb were obtained. The 62 240 unigenes were finally obtained by de novo splicing. After annotation, we discovered 19 unigenes involved in ginsenoside backbone biosynthesis. Additionally, 69 unigenes and 18 unigenes were predicted to have potential function of cytochrome P450 and UDP-glycosyltransferase based on the annotation results, which may encode enzymes responsible for ginsenoside backbone modification. This study provides global expressed datas for P. japonicus var. major, which will contribute significantly to further genome-wide research and analysis for this species.