The complete chloroplast genome sequence and phylogenetic analysis of the Bichetii grass Chlorophytum laxum (Asparagaceae).

Chlorophytum laxum of Asparagaceae is a valuable ornamental plant native to the tropical regions of Asia, Africa, and Australia. The plant also has medicinal properties and is used as source for folk medicine. Despite being commercially important, genetic studies of C. laxum are still limited. To expand the genomic information of this plant species, we sequenced, assembled, and characterized its complete chloroplast genome. The chloroplast genome was 153,678 bp in length, with a large single-copy region (83,225 bp) and a small single-copy region (18,031 bp) separated by a pair of inverted repeat regions (26,211 bp each). A total of 127 genes were predicted, including 81 protein-coding, 38 tRNA, and eight rRNA genes. The overall GC content was 37.3%. Based on current sampling size, phylogenetic analysis using the maximum likelihood based on the complete chloroplast genome sequence revealed that the relationship in Chlorophytum is well resolved; C. laxum was closely related to C. rhizopendulum.

Haplotype-resolved genomes of octoploid species in Phyllanthaceae family reveal a critical role for polyploidization and hybridization in speciation.

The Phyllanthaceae family comprises a diverse range of plants with medicinal, edible, and ornamental value, extensively cultivated worldwide. Polyploid species commonly occur in Phyllanthaceae. Due to the rather complex genomes and evolutionary histories, their speciation process has been still lacking in research. In this study, we generated chromosome-scale haplotype-resolved genomes of two octoploid species (Phyllanthus emblica and Sauropus spatulifolius) in Phyllanthaceae family. Combined with our previously reported one tetraploid (Sauropus androgynus) and one diploid species (Phyllanthus cochinchinensis) from the same family, we explored their speciation history. The three polyploid species were all identified as allopolyploids with subgenome A/B. Each of their two distinct subgenome groups from various species was uncovered to independently share a common diploid ancestor (Ancestor-AA and Ancestor-BB). Via different evolutionary routes, comprising various scenarios of bifurcating divergence, allopolyploidization (hybrid polyploidization), and autopolyploidization, they finally evolved to the current tetraploid S. androgynus, and octoploid S. spatulifolius and P. emblica, respectively. We further discuss the variations in copy number of alleles and the potential impacts within the two octoploids. In addition, we also investigated the fluctuation of metabolites with medical values and identified the key factor in its biosynthesis process in octoploids species. Our study reconstructed the evolutionary history of these Phyllanthaceae species, highlighting the critical roles of polyploidization and hybridization in their speciation processes. The high-quality genomes of the two octoploid species provide valuable genomic resources for further research of evolution and functional genomics.

The characteristics of the complete chloroplast genome of Staurogyne concinnula (Hance) O. Kuntze (Acanthaceae).

Staurogyne concinnula (Hance) O. Kuntze (Acanthaceae) is an important ornamental herb mainly distributed in the southern region of China, including Fujian, Guangdong, Hainan, and Taiwan provinces. However, the complete chloroplast genome of S. concinnula, which could serve as a genetic resource for studies on its taxonomy and evolution, is poorly studied at present. In this study, we reported the complete chloroplast genome of S. concinnula that was assembled using high-throughput sequencing data. The chloroplast genome was 153,783 bp long, with a typical quadripartite structure containing a small single-copy region (SSC; 17,855 bp), a large single-copy region (LSC; 84,636 bp) and a pair of inverted repeats (IRs; each 25,646 bp). The overall GC content of the chloroplast genome was 38.04%. A total of 86 protein-coding genes (PCGs), 8 rRNA genes, and 37 tRNA genes were predicted. Phylogenetic analysis based on the combined sequences of 86 PCGs with the other 16 closely related species of Acanthaceae indicated that S. concinnula is closely related to Avicennia marina. The genomic data and finding from the phylogenetic studies of S. concinnula could provide useful information and give light to in-depth studies on the evolution pattern of the understudied species, as well as Staurogyne.

The complete chloroplast genome sequence of Clerodendrum cyrtophyllum from Guangzhou, China.

Clerodendrum cyrtophyllum is a well-known medicinal plant in southern China. Here, we presented the complete chloroplast (cp) genome of C. cyrtophyllum using Illumina high-throughput sequencing technology. The C. cyrtophyllum cp genome size is 152,004 bp with 38.13% GC content, including a pair of inverted repeat regions (IR, 51,592 bp) separated by a large single copy (LSC, 86,480 bp) and a small single copy region (SSC, 18,425 bp). It possesses 87 protein-coding genes, 37 tRNA genes and eight rRNA genes. Phylogenetic analysis fully shows that C. cyrtophyllum is closely related to Clerodendrum bungei and Clerodendrum lindleyi. Overall, the complete cp genome sequence of C. cyrtophyllum provides a valuable resource for genetic diversity, phylogenetic relationship, and species identification.

The complete chloroplast genome sequence of Dryobalanops aromatica.

Dryobalanops aromatica is a new species in the family of Lauraceae with high content of D-borneol, which is an important raw material of premium spices and medicine widely used in China. The genome and the molecular phylogenetic relation of this novel species had not been analyzed before. In this study, we present the complete sequence of chloroplast genome of D. aromatic, as well as its genome annotation. The complete chloroplast sequences in length were 152,696 bp, with two single-copy regions 93,610 bp and 18,902 bp in length, which were separated by two inverted repeat regions with 20,092 bp in length. In total, 128 genes were predicted with GC content at 39.16%. Phylogenetic analysis showed that D. aromatica is closest to Gossypium sturtianum in Lauraceae. The sequence and annotation of the chloroplast genome of Dryobalanops aromatic will be useful for further studies on the taxonomy in Lauraceae.

A high-quality genome assembly of Morinda officinalis, a famous native southern herb in the Lingnan region of southern China.

Morinda officinalis is a well-known medicinal and edible plant that is widely cultivated in the Lingnan region of southern China. Its dried roots (called bajitian in traditional Chinese medicine) are broadly used to treat various diseases, such as impotence and rheumatism. Here, we report a high-quality chromosome-scale genome assembly of M. officinalis using Nanopore single-molecule sequencing and Hi-C technology. The assembled genome size was 484.85 Mb with a scaffold N50 of 40.97 Mb, and 90.77% of the assembled sequences were anchored on eleven pseudochromosomes. The genome includes 27,698 protein-coding genes, and most of the assemblies are repetitive sequences. Genome evolution analysis revealed that M. officinalis underwent core eudicot γ genome triplication events but no recent whole-genome duplication (WGD). Likewise, comparative genomic analysis showed no large-scale structural variation after species divergence between M. officinalis and Coffea canephora. Moreover, gene family analysis indicated that gene families associated with plant-pathogen interactions and sugar metabolism were significantly expanded in M. officinalis. Furthermore, we identified many candidate genes involved in the biosynthesis of major active components such as anthraquinones, iridoids and polysaccharides. In addition, we also found that the DHQS, GGPPS, TPS-Clin, TPS04, sacA, and UGDH gene families-which include the critical genes for active component biosynthesis-were expanded in M. officinalis. This study provides a valuable resource for understanding M. officinalis genome evolution and active component biosynthesis. This work will facilitate genetic improvement and molecular breeding of this commercially important plant.

The complete chloroplast genome sequence of Vernonia amygdalina Delile.

Vernonia amygdalina Delile is widely used in folkloric medicine for the treatment of various diseases. In this study, the complete chloroplast genome of V. amygdalina Delile was reported, which was assembled and annotated base on genome high-throughput sequencing data. This work provided the clues for the taxonomy of the herb and the potential to utilize the chloroplast genome sequence as a new study target. The length of V. amygdalina Delile chloroplast genome was 153,133bp, with two single-copy regions, each has the length of 84,245bp and 13,152bp respectively. This region were separated by two inverted repeat regions with 27,868bp in length. It was predicted to consist of 131 genes in total, including 86 protein-coding genes, 37 tRNA genes, 8 rRNA genes with GC content at 37.68%. Phylogenetic analysis by RAxML (Random Axelerated Maximum Likelikhood) showed V. amygdalina Delile is closest to Sonchus webbii in Compositae.

The complete chloroplast genome sequence of medicinal plant Alpinia chinensis (Retz.) Rosc.

Alpinia chinensis (Retz.) Rosc is one of Chinese tradition herbal medicine and edible plant in China. In this report, we sequenced the complete chloroplast genome of A. chinensis. Through the assembly annotation of genome with high-throughput sequencing data, which help us to research the evolution. The length of chloroplast sequences was 163,590 bp with a large single-copy region (LSC) and a small single-copy region (SSC), also, two inverted repeat region A (IR), whose length was 88,951, 15,299, and 29,670 bp, respectively. A total of 138 genes were predicted in the complete chloroplast genome, with 36.4% GC content, including 93 protein-coding genes, 37 tRNA genes, and 8 rRNA genes. From the phylogenetic analysis, we could conclude that A. chinensis (Retz.) Rosc. was close to Alpinia oxyphylla in Zingiberaceae.

The complete chloroplast genome sequence of Acanthopanax trifoliatus (Linn.) Merr.

Acanthopanax trifoliatus (Linn.) Merr. is an edible vegetables and medicinal plant from Asian countries. In this study, the complete chloroplast genome of A. trifoliatus was assembled and annotated by high-throughput sequencing. The total chloroplast genome size of A. trifoliatus was 156,716 bp, containing a large single-copy (LSC) region of 86,672 bp, a small single-copy (SSC) region of 18,174 bp, and a pair of inverted repeat regions of 25,935 bp. A total of 134 genes were predicted in the chloroplast genome of A. trifoliatus, including 89 protein-coding genes, 37 tRNA genes, and 8 rRNA genes. Phylogenetic analysis showed that A. trifoliatus was closely related to Eleutherococcus gracilistylus.

Antiproliferative effect of Dendrobium catenatum Lindley polypeptides against human liver, gastric and breast cancer cell lines.

Dendrobium catenatum Lindley is a precious plant with both dietary and medicinal applications. However, the antiproliferative activity of D. catenatum-derived peptides has not been investigated. In this study, the whole proteins of D. catenatum were extracted, hydrolysis with three proteases (alcalase 2.4L, alcalase 37017 and trypsin) was performed, and gel filtration chromatography was employed to obtain nine fractions. Fraction A3 possessed the best antiproliferative activity in vitro, with percentage inhibitions of 73.38%, 78.91% and 86.8% against HepG-2, SGC-7901 and MCF-7 cancer cells, respectively, and an inhibition of only 5.52% against L-O2 normal liver cells at 500 µg mL(-1). Subsequently, mass spectrometry revealed the existence of 10 alcalase-derived peptides in fraction A3, and the sequences of the three most abundant peptides were determined by de novo sequencing as: RHPFDGPLLPPGD, RCGVNAFLPKSYLVHFGWKLLFHFD and KPEEVGGAGDRWTC. Moreover, these peptides were synthesized and their antiproliferative activities in vitro were also confirmed. This suggests that fraction A3 may be promising for use in food and pharmaceutical applications.

[Correlation analysis of major agronomic characters and the polysaccharide contents in Dendrobium officinale].

OBJECTIVE: In order to provide theoretical and technological basis for the germplasm innovation and variety breeding in Dendrobium officinale, a study of the correlation between polysaccharide content and agronomic characters was conducted. METHODS: Based on the polysaccharide content determination and the agronomic characters investigation of 30 copies (110 individual plants) of Dendrobium officinale germplasm resources, the correlation between polysaccharide content and agronomic characters was analyzed via path and correlation analysis. RESULTS: Correlation analysis results showed that there was a significant negative correlation between average spacing and polysaccharide content, the correlation coefficient was -0.695. And the blade thickness was positively correlated with the polysaccharide content, but the correlation was not significant. The path analysis results showed that the stem length was the maximum influence factor to the polysaccharide, and it was positive effect, the direct path coefficient was 1.568. CONCLUSION: According to thess results, the polysaccharide content can be easily and intuitively estimated by the agronomic characters investigating data in the germpalsm resources screening and variety breeding. Therefore, it is a visual and practical technology guidance in quality variety breeding of Dendrobium officinale.