The complete chloroplast genome of Artemisia annua (Asteraceae), the primary source of artemisinin, was sequenced and analyzed. The A. annua cp genome is 150,995 bp, and harbors a pair of inverted repeat regions (IRa and IRb), of 24,850 bp each that separate large (LSC, 82,988 bp) and small (SSC, 18,267 bp) single-copy regions. Our annotation revealed that the A. annua cp genome contains 113 genes and 18 duplicated genes. The gene order in the SSC region of A. annua is inverted; this fact is consistent with the sequences of chloroplast genomes from three other Artemisia species. Fifteen (15) forward and seventeen (17) inverted repeats were detected in the genome. The existence of rich SSR loci in the genome suggests opportunities for future population genetics work on this anti-malarial medicinal plant. In A. annua cpDNA, the rps19 gene was found in the LSC region rather than the IR region, and the rps19 pseudogene was absent in the IR region. Sequence divergence analysis of five Asteraceae species indicated that the most highly divergent regions were found in the intergenic spacers, and that the differences between A. annua and A. fukudo were very slight. A phylogenetic analysis revealed a sister relationship between A. annua and A. fukudo. This study identified the unique characteristics of the A. annua cp genome. These results offer valuable information for future research on Artemisia species identification and for the selective breeding of A. annua with high pharmaceutical efficacy.

Ginseng, the root and rhizome of Panax ginseng C. A. Mey., is a famous herbal medicine, and its major ginsenosides exert beneficial effects on nonalcoholic fatty liver disease (NAFLD). Due to the multicomponent and multitarget features of ginsenosides, their detailed mechanisms remain unclear. This study aimed to explore the role of ginsenosides on NAFLD and the potential mechanisms mediated by the gut microbiota and related molecular processes. C57BL/6J mice were fed a high-fat diet (HFD) supplemented or not supplemented with ginsenoside extract (GE) for 12 weeks. A strategy that integrates bacterial gene sequencing, serum pharmacochemistry and network pharmacology was applied. The results showed that GE significantly alleviated HFD-induced NAFLD symptoms in a dose-dependent manner. Furthermore, GE treatment modulated the HFD-induced imbalance in the gut microbiota and alleviated dysbiosis-mediated gut leakage and metabolic endotoxemia. Additionally, 20 components were identified in the mouse plasma after the oral administration of GE, and they interacted with 82 NAFLD-related targets. A network analysis revealed that anti-inflammatory effects and regulation of the metabolic balance might be responsible for the effects of GE on NAFLD. A validation experiment was then conducted, and the results suggested that GE suppressed NF-κB/IκB signaling activation and decreased the release and mRNA levels of proinflammatory factors (TNF-α, IL-1β and IL-6). Additionally, GE promoted hepatic lipolytic genes (CPT-1a), inhibited lipogenic genes (SREBP-1c, FAS, ACC-1) and improved leptin resistance. These findings imply that the benefits of GE are involved in modulating the gut microbiota, enhancing the gut barrier function, restoring the energy balance, and alleviating metabolic inflammation. Moreover, GE might serve as a potential agent for the prevention of NAFLD through the integration of prebiotic, anti-inflammatory and energy-regulatory effects.

Gut microbiota mainly function in the biotransformation of primary ginsenosides into bioactive metabolites. Herein, we investigated the effects of three prebiotic fibers by targeting gut microbiota on the metabolism of ginsenoside Rb1 in vivo. Sprague Dawley rats were administered with ginsenoside Rb1 after a two-week prebiotic intervention of fructooligosaccharide, galactooligosaccharide, and fibersol-2, respectively. Pharmacokinetic analysis of ginsenoside Rb1 and its metabolites was performed, whilst the microbial composition and metabolic function of gut microbiota were examined by 16S rRNA gene amplicon and metagenomic shotgun sequencing. The results showed that peak plasma concentration and area under concentration time curve of ginsenoside Rb1 and its intermediate metabolites, ginsenoside Rd, F2, and compound K (CK), in the prebiotic intervention groups were increased at various degrees compared with those in the control group. Gut microbiota dramatically responded to the prebiotic treatment at both taxonomical and functional levels. The abundance of Prevotella, which possesses potential function to hydrolyze ginsenoside Rb1 into CK, was significantly elevated in the three prebiotic groups (P < 0.05). The gut metagenomic analysis also revealed the functional gene enrichment for terpenoid/polyketide metabolism, glycolysis, gluconeogenesis, propanoate metabolism, etc. These findings imply that prebiotics may selectively promote the proliferation of certain bacterial stains with glycoside hydrolysis capacity, thereby, subsequently improving the biotransformation and bioavailability of primary ginsenosides in vivo.

We sequenced and analyzed the complete chloroplast genome of Aster tataricus (family Asteraceae), a Chinese herb used medicinally to relieve coughs and reduce sputum. The A. tataricus chloroplast genome was 152,992 bp in size, and harbored a pair of inverted repeat regions (IRa and IRb, each 24,850 bp) divided into a large single-copy (LSC, 84,698 bp) and a small single-copy (SSC, 18,250 bp) region. Our annotation revealed that the A. tataricus chloroplast genome contained 115 genes, including 81 protein-coding genes, 4 ribosomal RNA genes, and 30 transfer RNA genes. In addition, 70 simple sequence repeats (SSRs) were detected in the A. tataricus chloroplast genome, including mononucleotides (36), dinucleotides (1), trinucleotides (23), tetranucleotides (1), pentanucleotides (8), and hexanucleotides (1). Comparative chloroplast genome analysis of three Aster species indicated that a higher similarity was preserved in the IR regions than in the LSC and SSC regions, and that the differences in the degree of preservation were slighter between A. tataricus and A. altaicus than between A. tataricus and A. spathulifolius. Phylogenetic analysis revealed that A. tataricus was more closely related to A. altaicus than to A. spathulifolius. Our findings offer valuable information for future research on Aster species identification and selective breeding.

Herbgenomics provides a global platform to explore the genetics and biology of herbs on the genome level. Panax ginseng C.A. Meyer is an important medicinal plant with numerous pharmaceutical effects. Previous reports mainly discussed the transcriptome of ginseng at the organ level. However, based on mass spectrometry imaging analyses, the ginsenosides varied among different tissues. In this work, ginseng root was separated into three tissues—periderm, cortex and stele—each for five duplicates. The chemical analysis and transcriptome analysis were conducted simultaneously. Gene-encoding enzymes involved in ginsenosides biosynthesis and modification were studied based on gene and molecule data. Eight widely-used ginsenosides were distributed unevenly in ginseng roots. A total of 182,881 unigenes were assembled with an N50 contig size of 1374 bp. About 21,000 of these unigenes were positively correlated with the content of ginsenosides. Additionally, we identified 192 transcripts encoding enzymes involved in two triterpenoid biosynthesis pathways and 290 transcripts encoding UDP-glycosyltransferases (UGTs). Of these UGTs, 195 UGTs (67.2%) were more highly expressed in the periderm, and that seven UGTs and one UGT were specifically expressed in the periderm and stele, respectively. This genetic resource will help to improve the interpretation on complex mechanisms of ginsenosides biosynthesis, accumulation, and transportation.

Heat stress is one of the most frequently encountered environmental stresses for most mushroom-forming fungi. Currently available fungal genomes are mostly haploid because high heterozygosity hinders diploid genome assembly.