Mining, expression, and phylogenetic analysis of volatile terpenoid biosynthesis-related genes in different tissues of ten Elsholtzia species based on transcriptomic analysis

• Published in: Phytochemistry (Oxford) 2022-11, Vol.203, p.113419-113419, Article 113419
• Main Authors: Geng, Xiuwen, Tang, Renhua, Zhang, Aili, Du, Zhizhi, Yang, Lipan, Xu, Yuqi, Zhong, Yiling, Yang, Run, Chen, Wenyun, Pu, Chunxia
• Format: Article
• Language: English
• Subjects: Elsholtzia; Elsholtzieae; Essential oil; Phylogenetic analysis; Transcriptome; Volatile terpenoids
• ISSN: 0031-9422; 1873-3700
• DOI: 10.1016/j.phytochem.2022.113419

We sequenced the leaf and inflorescence transcriptomes of 10 Elsholtzia species to mine genes related to the volatile terpenoid metabolic pathway. A total of 184.68 GB data and 1,231,162,678 clean reads were obtained from 20 Elsholtzia samples, and 333,848 unigenes with an average length of at least 1440 bp were obtained by Trinity assembly. KEGG pathway analysis showed that there were three pathways related to volatile terpene metabolism: terpenoid backbone biosynthesis (No. ko00900), monoterpenoid biosynthesis (No. ko00902), and sesquiterpenoid and triterpenoid biosynthesis (No. ko00909), with 437, 125, and 121 related unigenes, respectively. The essential oil content and composition in 20 Elsholtzia samples were determined by gas chromatography–mass spectrometry. The results showed that there were obvious interspecific differences among the 10 Elsholtzia species, but there were no significant differences between the different tissues among species. The expression levels of seven candidate genes involved in volatile terpenoid biosynthesis in Elsholtzia were further analyzed by quantitative real-time PCR. The results showed that HMGS had the highest expression among all genes, followed by GGPS4. In addition, there was not a significant correlation between the seven genes and the components with high essential oil contents. Combined with the essential oil components detected in this study, the possible biosynthetic pathway of the characteristic components in Elsholtzia plants was speculated to be a metabolic pathway with geraniol as the starting point and elsholtzione as the end product. Phylogenetic analysis was conducted using the nucleotide sequences of the geranyl diphosphate synthase candidate genes, and the results showed that genes related to the volatile terpenoid biosynthetic pathway may be more suitable gene fragments for resolving the Elsholtzia phylogeny. In different synthesis pathways, the expression level of volatile terpenoid synthesis related genes of inflorescence transcripts in 10 Elsholtzia species was generally higher than that of leaf transcripts. [Display omitted] •Transcriptome and essential oil analysis of 10 Elsholtzia species.•Exploration and identification of genes related to the volatile terpenoid metabolic pathways in 10 Elsholtzia plants.•There were obvious interspecific differences in essential oil components among the 10 Elsholtzia species.•The expression levels of volatile terpene synthesis related genes in inflorescences