Angelica decursiva is one of the lending traditional Chinese medicinal plants producing coumarins. Notably, several studies have focused on the biosynthesis and not the RT-qPCR (quantitative real-time reverse transcription polymerase chain reaction) study of coumarins. This RT-qPCR technique has been extensively used to investigate gene expression levels in plants and the selection of reference genes which plays a crucial role in standardizing the data form the RT-qPCR analysis. In our study, 11 candidate reference genes were selected from the existing transcriptome data of Angelica decursiva. Here, four different types of statistical algorithms (geNorm, NormFinder, BestKeeper, and Delta Ct) were used to calculate and evaluate the stability of gene expression under different external treatments. Subsequently, RefFinder analysis was used to determine the geometric average of each candidate gene ranking, and to perform comprehensive index ranking. The obtained results showed that among all the 11 candidate reference genes, SAND family protein (SAND), protein phosphatase 2A gene (PP2A), and polypyrimidine tract-binding protein (PTBP) were the most stable reference genes, where Nuclear cap binding protein 2 (NCBP2), TIP41-like protein (TIP41), and Beta-6-tubulin (TUBA) were the least stable genes. To the best of our knowledge, this work is the first to evaluate the stability of reference genes in the Angelica decursiva which has provided an important foundation on the use of RT-qPCR for an accurate and far-reaching gene expression analysis in this medicinal plant.

Quantitative real-time PCR (qPCR) has become a widely used approach to analyze the expression level of selected genes. However, owing to variations in cell types and drug treatments, a suitable reference gene should be selected according to special experimental design. In this study, we investigated the expression level of ten candidate reference genes in hepatoma carcinoma cell (HepG2) and human hepatocyte cell line (L02) treated with ethanol (EtOH), hydrogen peroxide (H2O2), acetaminophen (APAP), and carbon tetrachloride (CCl4), respectively. To analyze raw cycle threshold values (Cp values) from qPCR run, three reference gene validation programs, including Bestkeeper, geNorm, and NormFinder, were used to evaluate the stability of ten candidate reference genes. The results showed that TATA-box binding protein (TBP) and tubulin beta 2a (TUBB2a) presented the highest stability for normalization under different treatments and were regarded as the most suitable reference genes of HepG2 and L02. In addition, this study not only identified the most stable reference genes of each treatment, but also suggested that β-actin (ACTB), glyceraldehade-3-phosphate dehydrogenase (GAPDH), tyrosine 3-monooxygenase/tryptophan 5-monooxygenase activation protein zeta (YWHAZ), and beta-2 microglobulin (B2M) were the least stable reference genes in HepG2 and L02. This work was the first report to systematically explore the stability of reference genes in injured models of HepG2 and L02.

Saposhnikovia divaricata (Trucz.) Schischk. is a traditional Chinese herbal medicine widely distributed in Eastern Siberia and Northern Asia. In this research, we assembled and characterized the complete chloroplast genome sequence of S. divaricata from high-throughput sequencing data. The chloroplast genome was 147,834 bp in length, consisting of large single-copy (LSC) and small single-copy (SSC) regions of 93,202 bp and 17,324 bp, respectively, which were separated by a pair of 18,654 bp inverted repeat (IR) regions. The genome is expected to contain 129 genes, including 85 protein-coding genes, 36 tRNA genes, and 8 rRNA genes. The total GC content of the genome is 37.5%. A phylogenetic tree reconstructed by 40 chloroplast genomes reveals that S. divaricata is mostly related to Ledebouriella seseloides.

Corydalis yanhusuo is a medicinal plant frequently used in traditional Chinese medicine, which has effective medical effects in many aspects. Real-time polymerase chain reaction (RT-PCR) has been one of the most widely used methods in biosynthesis research due to its high sensitivity and quantitative properties in gene expression analysis. To obtain accurate normalization, reference genes are often selected in advance; however, no reference genes are available in C. yanhusuo. Herein, 12 reference gene candidates, named cyclophilin 2 (CYP2), elongation factor 1-α (EF1-α), protein phosphatase 2 (PP2A), SAND protein family (SAND), polypyrimidine tract-binding protein (PTBP), TIP41-like protein (TIP41), lyceraldehyde-3-phosphate hydrogenase (GAPDH), ubiquitin-conjugating enzyme 9 (UBC9), cyclophilin 1 (CYP1), tubulin beta (TUBA), thioredoxin (YLS8), and polyubiquitin 10 (UBQ10), were selected for stability analysis. After being treated with hormone, UV, salt, metal, oxidative, drought, cold (4 °C), and hot stresses (40 °C), the qRT-PCR data of the selected genes was analyzed with NormFinder, geNorm, and BestKeeper. The result indicated that GAPDH, SNAD, and PP2A were the top three most stable reference genes under most treatments. This study selected and validated reliable reference genes in C. yanhusuo under various environmental conditions, which can provide great help for future research on gene expression normalization in C. yanhusuo.

Tripterygium wilfordii is a perennial vine plant with medicinal value and belongs to the family of Celastraceae. In this study, we sequenced and analyzed the complete chloroplast genome of T. wilfordii . The chloroplast genome was 156,700 bp in length with a GC content of 37.47%. It contained two inverted repeat (IR) regions of 26,461 bp; each region was separated by large single-copy and small single-copy regions of 85,409 bp and 18,369 bp, respectively. In total, we annotated 134 unique genes, consisting of 89 protein-encoding genes, 8 rRNAs and 37 tRNAs. Phylogenetic analysis revealed that T. wilfordii was sister to T. regelii in a clade of Tripterygiumii species that was sister to a clade of Euonymus species.