Structural mutations of small single copy (SSC) region in the plastid genomes of five Cistanche species and inter-species identification

The complete chloroplast genome sequence and phylogenetic relationship analysis of Eomecon chionantha, one species unique to China

Eomecon chionantha Hance, an endemic species in China, has a long medical history in Chinese ethnic minority medicine and is known for its anti-inflammatory and analgesic effects. However, studies of E. chionantha are lacking. In this study, we investigated the characteristics of the E. chionantha chloroplast genome and determined the taxonomic position of E. chionantha in Papaveraceae via phylogenetic analysis. In addition, we determined molecular markers to identify E. chionantha at the molecular level by comparing the chloroplast genomes of E. chionantha and its closely related species. The complete chloroplast genomic information indicated that E. chionantha chloroplast DNA (178,808 bp) contains 99 protein-coding genes, 8 rRNAs, and 37 tRNAs. Meanwhile, we were able to identify a total of 54 simple sequence repeats through our analysis. Our findings from the phylogenetic analysis suggest that E. chionantha shares a close relationship with four distinct species, namely Macleaya microcarpa, Coreanomecon hylomeconoides, Hylomecon japonica, and Chelidonium majus. Additionally, using the Kimura two-parameter model, we successfully identified five hypervariable regions (ycf4-cemA, ycf3-trnS-GGA, trnC-GCA-petN, rpl32-trnL-UAG, and psbI-trnS-UGA). To the best of our knowledge, this is the first report of the complete chloroplast genome of E. chionantha, providing a scientific reference for further understanding of E. chionantha from the perspective of the chloroplast genome and establishing a solid foundation for the future identification, taxonomic determination and evolutionary analysis of this species.

The first complete chloroplast genome of Thalictrum fargesii: insights into phylogeny and species identification

Introduction

Thalictrum fargesii is a medicinal plant belonging to the genus Thalictrum of the Ranunculaceae family and has been used in herbal medicine in the Himalayan regions of China and India. This species is taxonomically challenging because of its morphological similarities to other species within the genus. Thus, herbal drugs from this species are frequently adulterated, substituted, or mixed with other species, thereby endangering consumer safety.

Methods

The present study aimed to sequence and assemble the entire chloroplast (cp) genome of T. fargesii using the Illumina HiSeq 2500 platform to better understand the genomic architecture, gene composition, and phylogenetic relationships within the Thalictrum.

Results and discussion

The cp genome was 155,929 bp long and contained large single-copy (85,395 bp) and small single-copy (17,576 bp) regions that were segregated by a pair of inverted repeat regions (26,479 bp) to form a quadripartite structure. The cp genome contains 133 genes, including 88 protein-coding genes (PCGs), 37 tRNA genes, and 8 rRNA genes. Additionally, this genome contains 64 codons that encode 20 amino acids, the most preferred of which are alanine and leucine. We identified 68 SSRs, 27 long repeats, and 242 high-confidence C-to-U RNA-editing sites in the cp genome. Moreover, we discovered seven divergent hotspot regions in the cp genome of T. fargesii, among which ndhD-psaC and rpl16-rps3 may be useful for developing molecular markers for identifying ethnodrug species and their contaminants. A comparative study with eight other species in the genus revealed that pafI and rps19 had highly variable sites in the cp genome of T. fargesii. Additionally, two special features, (i) the shortest length of the ycf1 gene at the IRA-SSC boundary and (ii) the distance between the rps19 fragment and trnH at the IRA-LSC junction, distinguish the cp genome of T. fargesii from those of other species within the genus. Furthermore, phylogenetic analysis revealed that T. fargesii was closely related to T. tenue and T. petaloidium.

Conclusion

Considering all these lines of evidence, our findings offer crucial molecular and evolutionary information that could play a significant role in further species identification, evolution, and phylogenetic studies on T. fargesii.

The complete chloroplast genome sequence of Nepeta bracteata and comparison with congeneric species

Nepeta bracteata (N. bracteata) is an important medicinal plant used by Chinese ethnic minorities. However, the lack of knowledge regarding the chloroplast genome of N. bracteata has imposed current limitations on our study. Here, we used Next-generation sequencing to obtain the chloroplast genome of N. bracteata. The findings suggested that the 151,588 bp cp genome of N. bracteata comprises 130 genes, including 35 tRNA genes and 87 protein-coding genes. And its chloroplast genome exhibits a typical quadripartite structure, the largest single copy (LSC; 82,819 bp) and the smallest single copy (SSC; 17,557 bp) separate a pair of inverted repeats IR regions (IRa and IRb; 25,606 bp) from one another. Interestingly, palindromic repeats are more common, as shown by the examination of repetition. In the interim, 18 SSRs were discovered in the interim, the bulk of which were Adenine-Thymine (A-T) mononucleotides. Meanwhile, we compared it with five other species from the Nepeta genus. Five hypervariable areas were found by the study, including ndhH-rps15, accD-psal, ndhG-ndhl, trnH-GUG-psbA, and rpoC1-rpoB. Furthermore, the phylogenetic study revealed that N. bracteata and Nepeta stewartiana (N. stewartiana) were linked to each other most closely. In summary, our findings enrich the resources available for chloroplast genomes in the Nepeta genus. Moreover, these hypervariable regions have the potential to be developed into molecular markers, enabling the rapid identification of species within the Nepeta genus. Comparative analysis of species within the Nepeta genus can help enhance our study of their phylogenetic relationships, potential medicinal properties and bioprospecting.

Comparative complete chloroplast genome of Geum japonicum: evolution and phylogenetic analysis

Geum japonicum (Rosaceae) has been widely used in China as a traditional herbal medicine due to its high economic and medicinal value. However, the appearance of Geum species is relatively similar, making identification difficult by conventional phenotypic methods, and the studies of genomics and species evolution are lacking. To better distinguish the medicinal varieties and fill this gap, we carried out relevant research on the chloroplast genome of G. japonicum. Results show a typical quadripartite structure of the chloroplast genome of G. japonicum with a length of 156,042 bp. There are totally 131 unique genes in the genome, including 87 protein-coding genes, 36 tRNA genes, and 8 rRNA genes, and there were also 87 SSRs identified and mostly mononucleotide Adenine-Thymine. We next compared the plastid genomes among four Geum species and obtained 14 hypervariable regions, including ndhF, psbE, trnG-UCC, ccsA, trnQ-UUG, rps16, psbK, trnL-UAA, ycf1, ndhD, atpA, petN, rps14, and trnK-UUU. Phylogenetic analysis revealed that G. japonicum is most closely related to Geum aleppicum, and possibly has some evolutionary relatedness with an ancient relic plant Taihangia rupestris. This research enriched the genome resources and provided fundamental insights for evolutionary studies and the phylogeny of Geum.

Revealing ecotype influences on Cistanche sinensis: from the perspective of endophytes to metabolites characteristics

Introduction

Plant microorganism is critical to plant health, adaptability, and productive forces. Intriguingly, the metabolites and microorganisms can act upon each other in a plant. The union of metabolomics and microbiome may uncover the crucial connections of the plant to its microbiome. It has important benefits for the agricultural industry and human being health, particularly for Chinese medical science investigation.

Methods

In this last 2 years study, on the strength of the UPLC-MS/MS detection platform, we accurately qualitatively, and quantitatively measured the Cistanche sinensis fleshy stems of two ecotypes. Thereafter, through high-throughput amplicon sequencing 16S/ITS sequences were procured.

Results

PhGs metabolites including echinacoside, isoacteoside, and cistanoside A were significantly downregulated at two ecotypes of C. sinensis. Add up to 876 metabolites were monitored and 231 differential metabolites were analyzed. Further analysis of 34 core differential metabolites showed that 15 compounds with up-regulated belonged to phenolic acids, flavonoids, and organic acids, while 19 compounds with down-regulated belonged to phenolic acids, flavonoids, alkaloids, amino acids, lipids, and nucleotides. There was no noteworthy discrepancy in the endophytic bacteria's α and β diversity between sandy and loam ecotypes. By comparison, the α and β diversity of endophytic fungi was notably distinct. The fungal community of the loam ecotype is more abundant than the sandy ecotype. However, there were few such differences in bacteria. Most abundant genera included typical endophytes such as Phyllobacterium, Mycobacterium, Cistanche, Geosmithia, and Fusarium. LEfSe results revealed there were 11 and 20 biomarkers of endophytic bacteria and fungi in C. sinensis at two ecotypes, respectively. The combination parsing of microflora and metabolites indicated noteworthy relativity between the endophytic fungal communities and metabolite output. Key correlation results that Anseongella was positive relation with Syringin, Arsenicitalea is negative relation with 7-methylxanthine and Pseudogymnoascus is completely positively correlated with nepetin-7-O-alloside.

Discussion

The aim of this research is: (1) to explore firstly the influence of ecotype on C. sinensis from the perspective of endophytes and metabolites; (2) to investigate the relationship between endophytes and metabolites. This discovery advances our understanding of the interaction between endophytes and plants and provides a theoretical basis for cultivation of C. sinensis in future.

The Complete Chloroplast Genome Sequence of Laportea bulbifera (Sieb. et Zucc.) Wedd. and Comparative Analysis with Its Congeneric Species

Laportea bulbifera (L. bulbifera) is an important medicinal plant of Chinese ethnic minorities, with high economic and medicinal value. However, the medicinal materials of the genus Laportea are prone to be misidentified due to the similar morphological characteristics of the original plants. Thus, it is crucial to discover their molecular marker points and to precisely identify these species for their exploitation and conservation. Here, this study reports detailed information on the complete chloroplast (cp) of L. bulbifera. The result indicates that the cp genome of L. bulbifera of 150,005 bp contains 126 genes, among them, 37 tRNA genes and 81 protein-coding genes. The analysis of repetition demonstrated that palindromic repeats are more frequent. In the meantime, 39 SSRs were also identified, the majority of which were mononucleotides Adenine-Thymine (A-T). Furthermore, we compared L. bulbifera with eight published Laportea plastomes, to explore highly polymorphic molecular markers. The analysis identified four hypervariable regions, including rps16, ycf1, trnC-GCA and trnG-GCC. According to the phylogenetic analysis, L. bulbifera was most closely related to Laportea canadensis (L. canadensis), and the molecular clock analysis speculated that the species originated from 1.8216 Mya. Overall, this study provides a more comprehensive analysis of the evolution of L. bulbifera from the perspective of phylogenetic and intrageneric molecular variation in the genus Laportea, which is useful for providing a scientific basis for further identification, taxonomic, and evolutionary studies of the genus.