目的 对丹参进行转录组测序，分析丹参不同组织响应适度干旱胁迫的分子机制。方法 以栽培4个月的丹参为材料，设置适度干旱胁迫组（土壤相对含水量55%~60%）和对照组（土壤相对含水量75%~80%），应用Illumina HiSeq 2000分别对根和叶进行转录组测序，对测序后的结果进行基因功能注释、差异表达基因（differentially expressed genes，DEGs）筛选和共表达网络分析等。结果 转录组测序共获得58 085条Unigene。其中28 846条被注释，根和叶中的DEGs分别有1 853、1 457个。GO富集结果表明，丹参根和叶中的DEGs在GO功能部位中的分布基本一致，均在代谢过程、刺激响应、细胞结构、催化活性等功能中得到显著富集。KEGG途径富集分析表明，根中DEGs显著富集在DNA复制、植物激素信号转导、植物-病原菌相互作用、胡萝卜素合成等途径，叶中DEGs则主要富集在氨基酸、生物碱、苯丙烷类生物合成等途径。适度干旱胁迫能促进丹参叶中苯丙烷类、根中萜类化合物生物合成途径关键酶基因的表达，是促进丹参有效成分累积的基础。AP2/ERF、bHLH、bZIP、WRKY、MYB类转录因子在根和叶中差异表达均较显著，基因共表达网络分析预测了在适度干旱胁迫下可能参与调控萜类基因表达的转录因子。结论 通过高通量转录组测序，揭示了适度干旱胁迫对丹参不同组织基因表达的调控特征，可为深入研究丹参药效成分的生物合成机制和在栽培中的合理灌溉提供科学依据。

Objective To analyze the molecular mechanism of different tissues of Salvia miltiorrhiza in response to moderate drought stress by transcriptome sequencing. Methods The roots and leaves of 4-month-old S. miltiorrhiza from moderate drought stressed group and control group (the relative water content in soil was 55%-60% and 75%-80%, respectively) were used as the test material. And the transcriptome sequencing analysis was carried out by using Illumina HiSeq 2000. After obtaining transcriptome data, gene function annotation, differentially expressed genes (DEGs) screening and and co-expression network analysis were performed. Results A total of 58 085 Unigenes were obtained by transcriptome sequencing. Among them, 28 846 Unigenes were annotated, and there were 1 853 and 1 457 DEGs in roots and leaves, respectively. The GO enrichment results showed that the DEGs of the roots and leaves were both significantly enriched in metabolic process, stimulus response, cell structure, and catalytic activity, etc. The KEGG pathway analysis showed that DEGs in roots were significantly enriched in DNA replication, plant hormone signal transduction, plant-pathogen interaction, and carotenoid biosynthesis, etc. And the DEGs in leaves were mainly concentrated in amino acids, alkaloids, and phenylpropanoid biosynthesis. The genes of key enzymes involved in phenylpropanoid and terpenoid biosynthesis were up-regulated by moderate drought stress, which might be the basis for accelerating the accumulation of active ingredients in leaves and roots of S. miltiorrhiza. AP2/ERF, bHLH, bZIP, WRKY, and MYB transcription factors were significantly differentially expressed in roots and leaves. Gene co-expression network analysis predicted transcription factors that may be involved in regulating the expression of terpenoid genes under moderate drought stress. Conclusion The high-throughput transcriptome sequencing revealed the regulatory characteristics of moderate drought stress on gene expression in different tissues of S. miltiorrhiza, which could provide scientific basis for further research on the biosynthesis mechanism of medicinal components of S. miltiorrhiza and reasonable irrigation in cultivation.

R286.12

国家自然科学基金资助项目（81573537）