目的 获得远志Polygala tenuifolia响应茉莉酸甲酯（methyl jasmonate，MeJA）处理的转录组学信息，挖掘远志三萜类化合物骨架生物合成的关键酶基因。方法 以生长30 d的远志组培苗为材料，分别用无菌水（CK）、50 μmol/L MeJA、100 μmol/L MeJA处理24 h，采用Illunima Hiseq^TM 2000 150PE进行转录组测序，使用Trinity软件完成Unigene的de novo拼接，基于BLAST实现Unigene的分类、功能注释、代谢通路分析、蛋白功能注释、差异基因分析和筛选等。结果 最终获得52.19 Gb数据，通过de novo拼接注释得到Unigene 54 426条，平均长度为1 604 bp，注释成功率100%。通过对MeJA处理前后基因进行差异分析，共筛选出差异基因3 390个，其中有1 287个上调，2 103个下调，且以100 μmol/L MeJA处理的差异基因总数及上调数最高。KEGG富集分析表明，差异基因主要富集于苯丙烷类生物合成、半胱氨酸与蛋氨酸代谢、淀粉蔗糖代谢、光合生物的固碳作用、萜类骨架生物合成等KEGG通路中。找到与远志三萜类骨架生物合成相关的基因59条，其中AACT、HMGS、HMGR、MK、PMK、MPD、DXS、IDI、FPPS、SQS、SE和β-AS受MeJA诱导后表达量上调。结论 对MeJA处理后的远志幼苗转录组进行分析，获得远志三萜类骨架生物合成相关的候选基因，MeJA可以诱导其三萜类骨架合成相关基因的表达，为远志的分子生物学研究提供了丰富的数据资源，也为后期开展远志三萜皂苷类化合物次生代谢途径解析奠定了基础。

Objective To obtain the transcriptome sequence database induced by methyl jasmonate (MeJA) and identify the genes related to the biosynthesis of triterpenoid saponin in Polygala tenuifolia. Methods The seedlings grown for 30 d were respectively treated with sterile water, 50 μmol/L MeJA and 100 μmol/L MeJA for 24 h. The transcriptome data of seedlings of P. tenuifolia were obtained by Illunima Hiseq^TM 2000 150PE sequencing and de novo splicing of Unigene was realized by Trinity software. The GO classification, KOG functional annotation, metabolism of KEGG metabolic pathway, protein function annotation analysis, differential gene analysis and screening were completed based on BLAST. Results A total of 52.19 Gb clean data were obtained after the transcriptome of P. tenuifolia being assembled by Trinity software, and 54 426 Unigenes were assembled with an average length of 1 604 bp. All Unigenes were annotated in the public databases NR, NT, KEGG, Swissprot, GO, and Pfam. Through differential analysis of genes responding to MeJA, a total of 3 390 differentially expressed genes (DEGs) were found, of which 1 287 were up-regulated and 2 103 were down-regulated. The response of DEGs showed that the total number and up-regulated number of P. tenuifolia seedlings treated by 100 μmol/L MeJA was the highest. KEGG enrichment analysis showed that differentially expressed genes were significantly enriched in metabolic pathways including phenylpropanoid biosynthesis, cysteine and methionine metabolism, starch and sucrose metabolism, carbon fixation in photosynthetic organisms and terpenoid backbone biosynthesis. Furthermore, a total of 59 Unigenes involved in anthraquinones biosynthesis were found according to the assignment of KEGG pathway. Expression analysis showed that AACT, HMGS, HMGR, MK, PMK, MPD, DXS, IDI, FPPS, SQS, SE and β-AS were up-regulated after being induced by MeJA. Conclusion In this study, the transcriptome of P. tenuifolia seedlings treated with methyl jasmonate was analyzed, and candidate genes related to triterpenoid skeleton biosynthesis of P. tenuifolia were obtained. MeJA can induce the expression of genes related to triterpenoid skeleton synthesis, which provided a wealth of data resources for the molecular biology research and also laid the foundation for the analysis of the secondary metabolic pathways of triterpenoid saponins in P. tenuifolia.

R282.12

公益性行业（中医药）科研专项经费项目（201507002-1-08）；陕西中医药大学“秦药”品质评价及资源开发学科创新团队项目（2019-QN01）；2019年医疗服务与保障能力提升补助资金（中医药事业传承与发展部分）“全国中药资源普查项目”（财社[2019]39号)