As a kind of traditional Chinese medicine, Pulsatilla chinensis (Bunge) Regel is well known for its anti-inflammation and anti-cancer activities, which are attributed to its active components including total saponins and monomers. To clarify the synthesis and metabolism mechanisms of class components in callus terpenes of P. chinensis, a certain concentration of salicylic acid (SA) hormone elicitor was added to the callus before being analysed by transcriptomic and metabolomic techniques. Results showed that the content of Pulsatilla saponin B4 in the callus suspension culture was significantly increased up to 1.99% with the addition of SA. Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis showed that the differentially expressed genes were mainly enriched in 122 metabolic pathways, such as terpenoid metabolism-related pathways: terpenoid skeleton synthesis pathway, monoterpenoid biosynthesis pathways, diterpenoid biosynthesis pathways, and ubiquinone and other terpenoid-quinone biosynthesis pathways. A total of 31 differentially accumulated metabolites were obtained from four differential groups. Amongst 21 kinds of known chemical components in P. chinensis, deoxyloganic acid was the only monoterpenoid; the others are triterpenoids. In summary, this study found that SA elicitors can affect the metabolic changes of terpenoids in P. chinensis callus, which provided a basis for analysing the genetic regulation of terpenoid components of leucons.

Pulsatilla chinensis (Bunge) Regel has been widely used in the pharmaceutical industry. With the deepening of clinical application, the research on its plant resources has attracted much attention. However, the underlying molecular mechanisms of distinct germination during Pulsatilla seed development are still mostly unknown. Therefore, in this study, four germination stages of P. chinensis seeds, with obvious differences in seed appearance traits, were used as materials. Transcriptome sequencing technology was used to analyse the molecular mechanisms of seed germination. A total of 27,601 differentially expressed genes (DEGs) (six different groups) were determined. KEGG enrichment analysis revealed that the up-regulated DEGs were enriched in phenylpropanoid biosynthesis, photosynthesis, photosynthesis–antenna proteins, plant hormone signal transduction, flavonoid biosynthesis and other pathways. A total of 87 DEGs was enriched in phytohormone signal transduction pathways, including auxin (25), abscisic acid (13), gibberellin (6), ethylene (9) and cytokinin (7). Furthermore, a protein–protein interaction network was constructed using these DEGs. Some DEGs were validated by qRT-PCR analysis. This comprehensive analysis provided basic information on the key genes of plant hormone signal transduction pathways involved in the seed germination process of P. chinensis (Bunge) Regel.

Background: The chloroplast (cp) genome has unique and highly conserved characteristics and is therefore widely used in species identification and classification, as well as to improve the in–depth understanding of plant evolution. Methods: In this study, the cp genomes of 13 Lamiaceae plants in the Tibet Autonomous Region of China were sequenced, assembled and annotated using bioinformatics methods. Phylogenetic trees were constructed to reveal the phylogenetic relationship of related species in the Lamiaceae. Results: The results showed that all 13 cp genomes had a typical four–segment structure, including one large single–copy (LSC) region, one pair of inverted repeat (IR) regions and one small single–copy (SSC) region. The sequence lengths of the 13 cp genomes were between 149,081 bp and 152,312 bp, and the average GC content was 37.6%. These genomes contained 131–133 annotated genes, including 86–88 protein–coding genes, 37–38 tRNA genes, and 8 rRNA genes. A total of 542 SSR loci were detected using MISA software. The repeat types were mostly single–nucleotide repeats, accounting for 61% of simple repeats. A total of 26,328–26,887 codons were detected in 13 cp genomes. According to the RSCU value analysis, the codons mostly ended with A/T. Analysis of IR boundaries showed that the other species were relatively conserved, except for Nepeta laevigata (D. Don) Hand.–Mazz., which differed in gene type and location on both sides of the boundary. By analysing nucleotide diversity, two highly mutated regions located in the LSC and SSC regions were identified in the 13 cp genomes. Conclusions: Using the cp genome of Lycium ruthenicum Murray as the outgroup, 97 cp genomes of the Lamiaceae were used to construct an Maximum Likehood (ML) phylogenetic tree, in which these species were divided into eight major clades, corresponding to eight subfamilies based on morphological classification. The phylogenetic results based on monophyletic relationships were consistent with the morphological classification status at the tribe level.