Comparative transcriptome analysis of roots, stems and leaves of Isodon amethystoides reveals candidate genes involved in Wangzaozins biosynthesis

作者：Feng-Lan Zhao, Mengchu Sun, Wanjun Zhang, Chunli Jiang, Jingtong Teng, Wei Sheng, Mingzhi Li, Aimin Zhang, Yongbo Duan, Jianping Xue · 发表于：BMC Plant Biology · 年份：2018 · DOI：10.1186/s12870-018-1505-0 · 被引用次数：55 · 研究领域：Bioactive Natural Diterpenoids Research、Plant-based Medicinal Research、Traditional Chinese Medicine Analysis

BACKGROUND: Isodon amethystoides (Ben-th) Cy Wu et Hsuan is an important traditional medicinal plant endowed with pharmacological properties effective in the treatment of various diseases, including pulmonary tuberculosis. The tetracyclic diterpenoids, Wangzaozins (Wangzaozin A, glaucocalyxin A, glaucocalyxin B), are the major bioactive compounds of I. amethystoides. However, the molecular information about the biosynthesis of these compounds still remains unclear. RESULTS: An examination of the accumulated levels of Wangzaozins in I. amethystoides revealed considerable variations in the root, stem, and leaf tissues of this plant, indicating possible differences in metabolite biosynthesis and accumulation among various tissues. To better elucidate the tetracyclic diterpenoid biosynthesis pathway, we generated transcriptome sequences from the root, stem, and leaf tissues, and performed de novo sequence assembly, yielding 230,974 transcripts and 114,488 unigenes, with average N50 lengths of 1914 and 1241 bp, respectively. Putative functions could be assigned to 73,693 transcripts (31.9%) based on BLAST searches against annotation databases, including GO, KEGG, Swiss-Prot, NR, and Pfam. Moreover, the candidate genes involving in the diterpenoid biosynthesis, such as CPS, KSL, were also analyzed. The expression profiles of eight transcripts, involving the tetracyclic diterpenoid biosynthesis, were validated in different I. amethystoides tissues by qRT-PCR, unraveling the gene exp...