ABSTRACT
As two original plants of Tibetan herb Jieji, Gentiana waltonii Burk. and Gentiana lhassica Burk. belong to Section Cruciata of Gentiana, Gentianaceae. Here, we report on whole chloroplast genome sequences in the alpine species, respectively, and the features of plastomes were investigated. The plastome of G. waltonii is 148 705 bp long (148 652 bp in G. lhassica) and encodes 112 genes, including 78 protein-coding genes, 30 transfer RNA genes, and 4 ribosomal RNA genes. Two pseudogenes, namely ψrps16 and ψinfA, were found in plastomes. In addition, two novel loci were detected, and a species-specific polymerase chain reaction assay was developed for differentiating G. waltonii and G. lhassica from 10 alpine species in Section Cruciata. Gentiana. Our study provides basic data for identifying Tibetan herbs, alpine species conservation and molecular phylogenetic studies of Gentiana and Gentianaceae.
ABSTRACT
The present paper reports for the first time the characteristics of the complete plastid genome of Surianaceae (Suriana maritima L.) in the order Fabales. The circular complete plastid genome is 163,747 bp in length with a typical quadripartite organization containing 115 unique genes, of which 80 are protein-coding genes, 31 tRNA genes and four rRNA genes. The plastid genome of S. maritima is characterized by absence of intron in the atpF gene, which has never been reported for any other species of the Fabales. The gene content and their orders in the plastid genome of Surianaceae are similar to the basal lineages of the legume family (Cercidoideae, Detarioideae) and Quillajaceae, supporting a likely common ancestor for the three families. Phylogenetic analysis supported the sister relationship between Surianaceae and Leguminosae, with strongly supported by Bayesian method and moderately supported by likelihood method. The complete plastid genome of Surianaceae could provide potential benefit in resolving the long-standing unresolved interfamily relationships of Fabaleswhen a more comprehensive sampling from Polygalaceae and Leguminosae is available for future studies.
ABSTRACT
Owing to its great medicinal and ornamental values, is frequently adulterated with other species on the market. Unfortunately, the utilization of the common DNA markers ITS, ITS2, and + is unable to distinguish from 5 closely related species of it (, , , and ). Here, we compared 63 plastomes comprising 40 newly sequenced plastomes of the 6 species and 23 previously published plastomes. The plastomes of and its closely related species were shown to have conserved genome structure and gene content. Comparative analyses revealed that small single copy region contained higher variation than large single copy and inverted repeat regions, which was mainly attributed to the loss/retention of genes. Furthermore, the intraspecific sequence variability among different species was shown to be diversified, which necessitates a cautious evaluation of genetic markers specific for different species. By evaluating the maximum likelihood trees inferred from different datasets, we found that the complete plastome sequence dataset had the highest discriminatory power for and its closely related species, indicating that complete plastome sequences can be used to accurately authenticate species.
ABSTRACT
species and their corresponding medicinal slices have been extensively used as traditional Chinese medicine (TCM) in many Asian countries. However, it is extremely difficult to identify species based on their morphological and chemical features. In this study, the plastomes of were used as a model system to investigate the hypothesis that plastomic mutational hotspot regions could provide a useful single nucleotide variants (SNVs) resource for authentication studies. We surveyed the plastomes of 17 species, including the newly sequenced plastome of . A total of 19 SNVs that could be used for the authentication of were detected. On the basis of this comprehensive comparison, we identified the four most informative hotspot regions in the plastome that encompass to , to , to and to . Furthermore, to established a simple and accurate method for the authentication of and its medicinal slices, a total of 127 samples from 20 species including their corresponding medicinal slices (Fengdous) were used in this study. Our results suggest that and its medicinal slices can be rapidly and unequivocally identified using this method that combines real-time PCR with the amplification refractory mutation system (ARMS).
ABSTRACT
Chloroplasts offer high-level transgene expression and transgene containment due to maternal inheritance, and are ideal hosts for biopharmaceutical biosynthesis via multigene engineering. To exploit these advantages, we have expressed 12 enzymes in chloroplasts for the biosynthesis of artemisinic acid (precursor of artemisinin, antimalarial drug) in an alternative plant system. Integration of transgenes into the tobacco chloroplast genome via homologous recombination was confirmed by molecular analysis, and biosynthesis of artemisinic acid in plant leaf tissues was detected with the help of 13C NMR and ESI-mass spectrometry. The excess metabolic flux of isopentenyl pyrophosphate generated by an engineered mevalonate pathway was diverted for the biosynthesis of artemisinic acid. However, expression of megatransgenes impacted the growth of the transplastomic plantlets. By combining two exogenous pathways, artemisinic acid was produced in transplastomic plants, which can be improved further using better metabolic engineering strategies for commercially viable yield of desirable isoprenoid products.