Expression Analysis of Two Chemical-Types of Artemisia Annua L. Terpenoids and Their Related Genes

  OBJECTIVE  To investigate the differential metabolites of two chemical-types of Artemisia annua and their possible causes by analyzing the data of terpenoid metabolites and their transcriptome of two chemical-types of Artemisia annua.

  METHODS  The seeds of Artemisia annua were collected from Xuyi County, Jiangsu Province, and Zhongmou County, Henan Province, in China, and grown under the same conditions. The volatile components of Artemisia annua were analyzed by headspace-gas chromatography-triple quadrupole mass spectrometry (HS-GC-QQQ-MS/MS), non-targeted analysis of the differential metabolites of 2 chemical-types of Artemisia annua were performed by ultra-fast liquid chromatography-triple quadrupole-time of flight tandem mass spectrometry (UFLC-Triple TOF-MS/MS), and the expression of the biosynthetic genes of the volatile components was analyzed by transcriptome sequencing.

  RESULTS  Based on the typing of volatile components, Artemisia annua from Xuyi County, Jiangsu Province was classified as artemisia ketone type, and Artemisia annua from Zhongmou County, Henan Province was classified as camphor type. The differential metabolites detected by UFLC-Triple TOF-MS/MS were significantly up-regulated in sesquiterpene, triterpene, and diterpene biosynthesis pathways by Kyoto encyclopedia of genes and genomes (KEGG) database analysis for artemisia ketone type and camphor types of Artemisia annua, respectively. The 2-methyl-D-erythritol-4-phosphate (MEP) pathway leading to terpene skeleton biosynthesis and the mevalonate (MVA) pathway annotated 23 candidate genes for 11 key enzymes that were significantly differential in the transcriptome data. In the monoterpene synthesis pathway, 10 candidate genes were detected for 1, 8-cineole synthase (TPS-Cin). In addition, two borneol dehydrogenase candidates were found to be highly expressed in camphor-type Artemisia annua, and three Artemisia annua alcohol dehydrogenase (ADH2) candidates were highly expressed in artemisia ketone-type Artemisia annua.

  CONCLUSION  This study provides scientific data to reveal the molecular mechanism of Artemisia annua chemical-types formation.