西洋参不同产地品质相关“地理特异基因群”的发掘

China is the largest consumer and second largest producing nations of American ginseng (Panax quinguefolium L.). Northeast China (Heilingjiang,Jilin and Liaoning province), Beijing and Shandong province is the three main producing areas in China. Quality varies widely among different areas. Our pilot studies demonstrated that American ginseng have two chemo-ecological types (ginsenoside Rb1/Re outside Shanhaiguan and ginsenoside Rg2/Rd inside Shanhaiguan) in different areas. However, the molecular mechanism ofthe variation of chemical ecology is unclear. Our hypothesis is that there are geographical specific genes in the specific eco-environment, and those genes are closely involved in ginsengoside biosynthesis (the major bioactive chemical constituents). Up to now, we have generated over 210,000 expressed sequence tags (ESTs) by high-throughput sequencing, and had over 300 candidate genes involved in ginsenoside synthesis. We also developed the ultra performance liquid chromatography (UPLC) coupled with PAD(UPLC-PAD) detection method to determinate the contents of ginsengosides. We have obtained the data of eco-factors difference in three producing areas using Geographic Information System for Traditional Chinese Medicine （TCMGIS）tool. In this project, we will screen and discover geographical specific genes in different locations by transcriptome analysis of technology (RNA-seq), bioinformatics and biological statistic methods. And those geographical specific genes are colsedly related to quality of P. quinguefolium.Our results will be helpful to clarify the biological nature of quality variation and ecological adaptation of American ginseng in different habitats. It's also usefule both for guidance of cultivation of American ginseng and for other multi-Daodi, multi-habitats Chinese herbal medicines research related to ecological adaptation.

中国是西洋参（Panax quinguefolium L.）第一大消费国和第二大生产国。东北、北京和山东是西洋参中国三大主产区。西洋参不同产地品质差异很大，课题组前期研究发现西洋参不同产地存在人参皂苷Rb1/Re关外型和Rg2/Rd关内型二种化学生态型，然而其化学生态变异的分子机制不清，据此我们提出在特定生态环境下，存在参与西洋参次生代谢途径中的关键酶基因表达的差异，即"地理特异基因群"。本研究已获得21万条表达序列标签ESTs和300多条参与西洋参皂苷合成相关的关键酶候选基因，已建立UPLC及联用技术分析西洋参皂苷类成分的方法，并通过中药材生态适宜性TCMGIS集成技术获得环境因子特征；拟运用转录组测序RNA-seq技术、生信学及生物统计分析发掘西洋参品质相关的地理特异基因群。研究结果为阐明西洋参不同产地品质差异和生态适应的生物学本质、正确指导生产及同类多道地中药材生态适应研究提供依据。

中国是西洋参（Panaxquinguefolium L.）第一大消费国和第二大生产国。东北、和山东是西洋参中国两大主产区。西洋参不同产地品质差异很大，课题组前期研究发现西洋参不同产地存在人参皂苷 Rb1/Re 关外型和 Rg2/Rd 关内型二种化学生态型，然而其化学生态变异的分子机制不清，据此我们提出在特定生态环境下，存在参与西洋参次生代谢途径中的关键酶基因表达的差异，即“地理特异基因群”。本项目以遗传—化学—生态特征结合的道地药材研究体系作为指导思路，完成了两大产地的西洋参样品皂苷类成分的定量分析测定，发现来自不同产地样品的化学变异规律。对西洋参转录组中生物合成通路及功能基因进行富集分析，对不同产地样品基因表达进行差异性分析。结合西洋参两大产地样品的化学测定结果，分析并验证与有效成分含量相关的代谢途径上关键酶基因的表达情况，发掘了西洋参品质相关的甲羟戊酸激酶(MK)，角鲨烯单加氧酶(SE)，磷酸甲羟戊酸激酶(PMK)等23条地理特异基因。化学分析表明，东北与山东产西洋参样品7种主要皂苷类成分含量存在显著差异。生态因子研究发现，东北三省在气候地理特征上均与山东有显著差异。本研究结果为阐明西洋参不同产地品质差异和生态适应的生物学本质、正确指导生产及同类多道地中药材生态适应研究提供依据。