艾草可燃性特征的转录组学研究

A Transcriptomic Study of the Flammability Characteristics of Artemisia argyi

目的探讨艾草可燃性特征的转录组学基础。方法采摘新鲜艾草后分别提取叶、根、茎组织的总RNA并建立3个组织的cDNA文库,进行高通量测序。对测序后的原始读段进行过滤得到高质量读段,使用Trinity软件对高质量读段进行de novo组装得到功能基因,再对功能基因进行京都基因和基因组百科全书(kyoto encyclopedia of genes and genomes,KEGG)注释和表达量的计算。结果艾草高通量测序获得99 807个功能基因,与KEGG数据库比对后得到萜类和纤维素合成的代谢通路,发现参与萜类物质合成的相关基因有116个,编码16种关键酶;参与纤维素合成相关基因有119个,编码5种关键酶。在萜类物质合成的关键酶基因中,叶、根、茎组织中都仅存在1个MVD基因和2个CMS基因,并且这3种关键酶基因均在叶中的表达水平最高。结论艾草中存在许多参与萜类和纤维素合成的关键酶基因,但其最关键的限速酶在艾叶中的表达量比根、茎高,这可能是艾叶作为灸材的关键因素之一。

Objective To study the flammability characteristics of Artemisia argyi （A. argyi） on the basis of transcriptome. Methods After picking fresh A. argyi, the total RNA of leaves, roots, and stems was extracted, and the cDNA libraries of the three tissues were established for high-throughput sequencing. High-quality reads were obtained by filtering the raw reads after sequencing, and then were de novo assembled using Trinity software to obtain functional genes, which were annotated by Kyoto Encyclopedia of Genes and Genomes （KEGG）, and the expression levels of functional genes were also calculated. Results By high-throughput sequencing of A. argyi, a total of 99 807 functional genes were obtained. After comparing them with the KEGG database, the metabolic pathways for terpenoids and cellulose syntheses were obtained. It was found that 116 genes were involved in the synthesis of terpenoids, and 16 key enzymes were encoded; 119 genes were involved in cellulose synthesis, and 5 key enzymes were encoded. Among the key enzymes for the synthesis of terpenoids, only one MVD gene and two CMS genes existed in each of leaves, roots, and stems, and the expression levels of these three key enzyme genes were highest in A. argyi leaves. Conclusion There are many key enzyme genes involved in terpenoids and cellulose syntheses in A. argyi, but the expression of the most critical ones, rate-limiting enzymes, in A. argyi leaves is higher than that in roots and stems, which may be one of the key factors for the selection of A. argyi leaves as moxibustion material.