Small Single-copy Region Research Articles

The complete chloroplast genome of Crataegus scabrifolia (Franch.) Rehd (Rosaceae), a medicinal and edible plant in Southwest China

Crataegus scabrifolia (Franch.) Rehd is a medicinal and edible plant in Southwest China. The chloroplast genome of C. scabrifolia was analyzed by high-throughput sequencing technology, and its genetic relationship to related species was discussed. The chloroplast genome is 159,637 bp long, with two inverted repeat (IR) regions (26,384 bp each) that separate a large single-copy (LSC) region (87,730 bp) and a small single-copy (SSC) region (19,139 bp). A total of 127 genes were annotated, including 83 protein-coding genes, 8 rRNA genes, and 36 tRNA genes. The phylogenetic tree shows that C. hupehensis is closely related to C. scabrifolia with strong bootstrap support.

The complete plastome of Centaurium erythraea subsp. majus (Hoffmanns. & Link) M.Laínz (Gentianaceae), the first chloroplast genome belonging to the Centaurium genus

Despite having many historically reported ethnomedicinal uses, Centaurium erythraea Rafn (Rafn and Buchs, 1800; common centaury) also produces cytotoxic secondary metabolites, and its presence should be carefully monitored. In this study, the complete chloroplast of Centaurium erythraea subsp. majus (Hoffmanns. & Link) M.Laínz (Laínz, 1971) isolate BPTPS121 is described, being the first available plastome belonging to the Centaurium genus. The chloroplast genome (GenBank accession number: ON641347) is 153,107 bp in length with 37.9% GC content, displaying a quadripartite structure that contains a pair of inverted repeat regions (25,166 bp each), separated by a large single-copy (84,388 bp) and small single-copy (18,387 bp) regions. A total of 129 genes were predicted, including 37 tRNA genes, eight rRNA genes, and 84 protein-coding genes. The phylogenetic analysis showed that isolate BPTPS121 is placed under the Gentianaceae family, belonging to the Gentianales order. The maximum-likelihood tree supports the already described lineage divergence in the Gentianaceae family, with C. erythraea subsp. majus belonging to the Chironieae tribe positioned below the Exaceae tribe and above the Potalieae and the entire Gentianeae tribes. This study will contribute to conservation, phylogenetic, and evolutionary studies, as well as DNA barcoding applications for food, feed, and supplements safety purposes.

The complete chloroplast genome sequence of Berchemia racemosa Siebold & Zucc. (Rhamnaceae), a rare plant species in Korea

Berchemia racemosa Siebold & Zucc., 1845 is a rare species distributed in restricted areas in the western Korean peninsula. In this study, the complete chloroplast genome (plastome) of B. racemosa was sequenced and assembled by Illumina paired-end sequencing. The plastome of B. racemosa was 161,187 bp in length and was quadripartite in structure, including a large single-copy (LSC) region of 89,503 bp, a small single-copy (SSC) region of 18,214 bp, and two inverted repeats of 26,735 bp. The GC content was 37.2%. The plastome of B. racemosa contains 130 genes, including eight ribosomal RNA (rRNA) genes, 37 transfer RNA (tRNA) genes, and 85 protein-coding genes. Phylogenetic analysis using complete genome sequences showed that B. racemosa is most closely related to Berchemia flavescens.

The complete chloroplast genome of Urtica angustifolia Fisch. ex Hornem. (Urticaceae), an important kind of traditional Chinese medicine in China

Urtica angustifolia Fisch. ex Hornem. is an important Chinese medicine. Here, the complete chloroplast genome of U. angustifolia was assembled and characterized. The length of the chloroplast genome was 146,679 bp with the typical quadripartite structure, containing two inverted repeats (IRs) of 24,595 bp separated by a large single-copy (LSC) region of 79,820 bp and a small single-copy (SSC) region of 17,669 bp. The whole chloroplast genome of U. angustifolia contains 111 genes, including 77 protein-coding genes, 30 tRNA genes, and 4 rRNA genes. Nucleotide variability analysis identified three hotspot regions (trnK-rps16, ndhF-rps32, and ycf1b) for genomic divergence and 52 simple sequence repeats. Phylogenetic analysis based on the complete chloroplast genomes exhibited that U. angustifolia formed a clade with Urtica lobatifolia and Hesperocnide tenella.

The complete chloroplast genome of Pseudotsuga sinensis, a China endemic species

In this study, we collected plant material from Pseudotsuga sinensis in Guizhou, China, and sequenced it. The complete chloroplast genome consisted of 122,243 bp, including a large single-copy (LSC) region, a small single-copy (SSC) region, and two inverted repeat regions like those in P. sinensis var. wilsoniana. The GC content of P. sinensis and P. sinensis var. wilsoniana are 38.7% and 38.8%, respectively. The reconstructed phylogenetic tree reveals that P. sinensis was a sister species to P. sinensis var. wilsoniana. Hence, the availability of the chloroplast genome of P. sinensis will promote further phylogenetic studies of the family Pinaceae.

The complete chloroplast genome of Cynoglossum amabile Stapf & J. R. Drumm., 1906 (Boraginaceae), a traditional Chinese herbal medicine

Cynoglossum amabile Stapf & J. R. Drumm., 1906 is a traditional Chinese herbal medicine from southwest China. To better determine its phylogenetic relatedness to other Boraginaceae species, the chloroplast (cp) genome of C. amabile was sequenced. The complete cp genome of C. amabile is 151,532 bp in length, containing a small single-copy (SSC) region with a length of 17,366 bp, a large single-copy (LSC) region with a length of 82,902 bp, and a pair of inverted repeats (IRs) regions each with a length of 25,632 bp. The overall GC content of the cp genome is 37.4%. The maximum-likelihood phylogenetic tree showed that Bothriospermum zeylanicum (J. Jacq.) Druce, 1917 was closely related to C. amabile.

The complete chloroplast genome of Tulipa sinkiangensis Z. M. Mao (Liliaceae) with multi-flower

Tulipa sinkiangensis Z. M. Mao 1980 is endemic to Xinjiang Province, China. In this study, we reported the complete chloroplast genome of T. sinkiangensis. The complete chloroplast genome of T. sinkiangensis comprises 151,929 bp and was divided into four typical regions: a large single-copy region of 82,062 bp, a pair of inverse repeats of 26,361 bp each, and a small single-copy region of 17,145 bp. A total of 136 genes were identified in this chloroplast, of which 87 were protein-coding, 38 were tRNA, eight were rRNA, and three were pseudogene. The results of this study will provide valuable information for understanding evolution and identification of different species belonging to genus Tulipa.

The complete chloroplast genome of a fast-growing tree Lophostemon confertus (Myrtaceae)

Lophostemon confertus (Myrtaceae), a fast-growing ornamental tree, is widely cultivated in tropical and subtropical regions. To determine its phylogenetic position within Myrtaceae, here we report its complete chloroplast (cp) genome, which is 160,297 bp long and contains two inverted repeats (IRs) of 26,490 bp each, separated by a small single-copy region of 18,826 bp and a large single-copy region of 88,491 bp. The cp genome contains 123 genes, including 73 unique protein-coding genes (six duplicated in the IR regions), 29 unique tRNA genes (seven duplicated in the IR regions), and four unique rRNA genes (all located in the IR regions). Phylogenetic analysis of 18 species of Myrtaceae showed that L. confertus is sister to Xanthostemon chrysanthus. The complete cp genome of L. confertus provides a valuable genetic resource for further phylogenetic studies.

The complete chloroplast genome and phylogenetic analysis of Christella dentata (Forssk.) Brownsey & Jermy (Thelypteridaceae)

Christella dentata (Forssk.) Brownsey & Jermy (Thelypteridaceae) is endemic to the tropical and subtropical regions of Africa, Asia, and Asia Pacific. In this study, the complete chloroplast genome sequence of C. dentata was assembled using next-generation sequencing data. The complete chloroplast genome was 151,662 bp in length and had a typical quadripartite structure, which consisted of a small single-copy region (21,776 bp) and a large single-copy region (82,624 bp) that were separated by a pair of inverted repeats (23,631 bp each). A total of 131 genes were predicted, including 89 protein coding (CDS), 34 tRNA, and eight rRNA genes. The overall GC content of the chloroplast genome was 42.48%. Based on the concatenated shared unique CDS sequence dataset, phylogenetic analysis using both the maximum-likelihood and the Bayesian inference methods revealed that C. dentata is placed within Thelypteridaceae and is closely related to Christella appendiculata. Such genetic information would be useful for studies on the evolution pattern in ferns. The availability of chloroplast genome sequence for the species also paves the way to resolving the complicated relationship among members of Christella.

The Chloroplast Genome Sequence Characteristics Analysis of Berberis diaphana Maxim

Berberis diaphana Maxim (B. diaphana), an important medicinal deciduous shrub, is narrowly endemic to China. In the present study, the complete chloroplast (cp) genome of B. diaphana was sequenced and analyzed. The complete cp genome of B. diaphana is 166, 225 bp in length, presenting a quadripartite structure comprising a large single copy region (LSC 73, 596 bp), a small single copy region (SSC 18, 656 bp), and a pair of inverted repeats regions (IRa/ IRb: 36, 954 bp each). The genomewide GC content was 38.07%, LSC made up 32.59%, SSC made up 32.59%, and IR made up 41.02%. The genome encodes 144 genes, including 99 protein-coding genes, 37 tRNA genes, and 8 rRNA genes. A total of 98 simple sequence repeats (SSRs) was identified. Codon usage analysis showed that the genome tended to use codon ending in A/U. Phylogenetic relationships of 20 species inferred that B. diaphana is sister to Berberis weiningensis. The genome comparison revealed that there is a wide variability of the junction sites, and there is higher divergence in the SSC and IRa/ IRb regions than in LSC regions. This study identified the unique characteristics of the B. diaphana cp genome, which will provide valuable information for further studies as well as molecular identification approaches for this important medicinal plant.

Loss of plastid ndh genes in an autotrophic desert plant

Plant plastid genomes are highly conserved with most flowering plants having the same complement of essential plastid genes. Here, we report the loss of five of the eleven NADH dehydrogenase subunit genes (ndh) in the plastid of a desert plant jojoba (Simmondsia chinensis). The plastid genome of jojoba was 156,496 bp with one large single copy region (LSC), a very small single copy region (SSC) and two expanded inverted repeats (IRA + IRB). The NADH dehydrogenase (NDH) complex is comprised of several protein subunits, encoded by the ndh genes of the plastome and the nucleus. The ndh genes are critical to the proper functioning of the photosynthetic electron transport chain and protection of plants from oxidative stress. Most plants are known to contain all eleven ndh genes. Plants with missing or defective ndh genes are often heterotrophs either due to their complete or holo- or myco- parasitic nature. Plants with a defective NDH complex, caused by the deletion/pseudogenisation of some or all the ndh genes, survive in milder climates suggesting the likely extinction of plant lineages lacking these genes under harsh climates. Interestingly, some autotrophic plants do exist without ndh gene/s and can cope with high or low light. This implies that these plants are protected from oxidative stress by mechanisms excluding ndh genes. Jojoba has evolved mechanisms to cope with a non-functioning NDH complex and survives in extreme desert conditions with abundant sunlight and limited water.

The complete chloroplast genome of Primula calliantha subsp. bryophila, an ornamental alpine plant from China

Primula calliantha subsp. bryophila (Balf. f. et Farrer) W.W. Smith and Forrest (1928) is a perennial alpine species with ornamental value. It is distributed in northwestern Yunnan and adjacent eastern Tibet of China, and northern Myanmar. Here, we sequenced and assembled complete plastid genome of P. calliantha subsp. bryophila, which is a circular molecule of 152,045 bp in length, including a large single-copy region (83,966 bp), a small single-copy region (17,663 bp), and a pair of inverted repeats (25,208 bp). The chloroplast genome contained 113 genes, including 79 protein-coding genes, four rRNA genes, and 30 tRNA genes. The phylogenetic tree based on chloroplast genomes showed the relative relationship of P. calliantha subsp. bryophila and P. calliantha, which further supports P. calliantha subsp. bryophila as a subspecies of P. calliantha in taxonomy. The complete chloroplast (cp) genome of P. calliantha subsp. bryophila provides valuable data for further phylogenetic studies of Primulaceae.

Complete chloroplast genome of Atractylodes japonica native to the Korean Peninsula and Atractylodes species identification challenges

Atractylodes japonica Koidz. ex. Kitam. (Asteraceae) is a perennial plant, of which the dried rhizome has been utilized as a traditional herbal medicine in East Asia. Here, we sequenced and annotated the complete chloroplast genome of A. japonica native to Korea. The circular genome was 153,207 bp in length and was composed of a large single-copy region (84,256 bp), a small single-copy region (18,657 bp), and a pair of inverted repeat regions (25,147 bp each). The annotation and manual curation of genes predicted a total of 114 genes, of which 80 were classified as protein-coding genes, 30 were transfer ribonucleic acid (RNA) genes, and 4 were ribosomal RNA genes. Phylogenetic analysis using 13 genomes from 6 Atractylodes species showed intermingled clustering of 9 genomes from 4 species, A. chinensis, A. japonica, A. koreana, and A. lancea, indicating ambiguity in their taxonomic identification.

The complete chloroplast genome sequence of Rhododendron fortunei: Structural comparative and phylogenetic analysis in the ericaceae family

Rhododendron fortunei (Ericaceae) possesses valuable horticultural and medicinal values. However, the genomic information on R. fortunei is very limited. In this study, the complete chloroplast genome (cp) of R. fortunei was assembled and annotated, SSR loci were characterised, comparative genomic analysis was carried out, and phylogenetic research was also performed. The results showed that the R. fortunei cp genome was of a typical quadripartite structure (200,997 bp). The lengths of the large single copy region (LSC), the inverted repeat regions (IR), and the small single copy region (SSC) were 109,151 bp, 2,604 bp, and 44,619 bp, respectively. A total of 147 unique genes were identified, including 99 protein-coding genes, 42 tRNA genes, and 6 rRNA genes, respectively. Leucine (11.51%) and cysteine (1.15%) were the highest and lowest representative amino acids, respectively. The total of 30 codons with obvious codon usage bias were all A/U-ending codons. Among the 77 simple sequence repeats, the majority were mononucleotide A/T repeats located in the intergenic spacer region. Five gene regions showed high levels of nucleotide diversity (Pi > 0.03). The comparative genome analysis revealed 7 hotspot intergenic regions (trnI-rpoB, trnTrpl16, rpoA-psbJ, rps7-rrn16, ndhI-rps16, rps16-rps19, and rrn16-trnI), showing great potential as molecular makers for species authentication. Expansion and contraction were detected in the IR region of the R. fortunei cp genome. In the phylogenetic tree, R. fortunei was closely related to R. platypodum. This research will be beneficial for evolutionary and genetic diversity studies of R. fortunei and related species among the Ericaceae family.

The complete chloroplast genome sequence of Vincetoxicum mongolicum (Apocynaceae), a perennial medicinal herb.

Vincetoxicum mongolicum Maxim. (1876), is a perennial medicinal herb, widely distributed in the Loess Plateau of China. Here, we sequenced, assembled, and annotated the complete chloroplast (cp) genome of V. mongolicum, and compared the highly variable gene regions and phylogenetic positions between V. mongolicum and other related species. Results showed that the complete cp genome of V. mongolicum was 160,157 bp in length, containing a large single copy (LSC) region of 91,263 bp, a pair of inverted repeats (IR) region of 23,892 bp, and a small single copy (SSC) region of 21,110 bp. The GC content accounts for 37.8%, and we annotated 131 single genes, which include 86 protein-coding genes, 8 rRNA genes, and 37 tRNA genes. By comparing and analyzing the variable region of the cp gene of V. mongolicum and other Vincetoxicum, we found that the variable sequences of rpoC1-rpoB, ycf4-cemA, ndhF, ndhF-rpl32, and rpl32-ccsA fragments were highly significant, which could be targeted as the DNA barcodes for evidence of V. mongolicum and its relatives in Apocynaceae. Maximum-likelihood (ML) phylogenetic tree analysis elucidated that V. mongolicum was sister to V. pycnostelma with strong support. Our results provide useful information for future phylogenetic studies and plastid super-barcodes of the family Apocynaceae.

Characterization and phylogenetic analysis of the complete chloroplast genome of Emilia sonchifolia (L.) DC.

Emilia sonchifolia is a herb with antioxidant, anti-inflammatory, antitumor, and wound healing properties. The complete chloroplast genome (cp genome) of the genus Emilia was sequenced for the first time. The cp genome of E. sonchifolia is 151,474 bp in length. It contained a large single-copy (LSC) region (84,004 bp), and small single-copy (SSC) region (17,980 bp), and two inverted repeats (IRs, 24,745 bp). Phylogenetic analysis of 24 species was conducted. E. sonchifolia was found to be closely related to Pericallis hybrida and Dendrosenecio spp. The sequenced cp genome would be useful to understand the phylogeny and genomic studies of the genus Emilia.

Phylogenetic implications and characterization of the chloroplast genome of Atractylodes macrocephala (Compositae), an herb species to China

The rhizome of Atractylodes macrocephala is one of the most commonly used herbs in China. In this paper, we presented the complete chloroplast genome of A. macrocephala. The chloroplast genome of A. macrocephala is 153,256 bp in length as the circular, which harbors a large single-copy (LSC) region 84,291 bp, a small single-copy (SSC) region of 18,675 bp and separated by a pair of inverted-repeat (IR) regions of 25,145 bp for each one. The overall nucleotide content of the chloroplast genome is 37.7% GC content. This chloroplast genome contains 125 genes, which includes 88 protein-coding genes (PCGs), 29 transfer RNA (tRNAs) and 8 ribosome RNA (rRNAs). Phylogenetic implications based on chloroplast genomes of 16 the family Compositae plant species indicated that Atractylodes macrocephala was closely related to Atractylodes lancea in the family Compositae by the Maximum-Likelihood (ML) method.

The chloroplast genome of Lappula myosotis V. Wolf, a medicinal species

Lappula myosotis V. Wolf 1776 is an annual or biennial plant with important medicinal value. In the present study, we report the complete chloroplast genome data of L. myosotis, which has a length of 146,668 bp, including a small single-copy (SSC) region of 17,059 bp, a large single-copy (LSC) region of 79,691 bp, and a pair of inverted repeats (IRs) of 24,959 bp. A total of 127 genes encoding tRNA and rRNA were annotated. The total CG content of the chloroplast genome was 37.7%. The maximum-likelihood (ML) phylogenetic tree strongly supported that L. myosotis is closely related to Trigonotis peduncularis. The complete chloroplast genome of L. myosotis provides useful information on the evolution and phylogenetic relationship among Boraginaceae plants.

Chloroplast genome skimming of a potential agroforestry species Melia dubia. Cav and its comparative phylogenetic analysis with major Meliaceae members.

The online version contains supplementary material available at 10.1007/s13205-022-03447-1.

Complete chloroplast genome sequence of <i>Clematis calcicola</i> (Ranunculaceae), a species endemic to Korea

The complete chloroplast genome (cp genome) sequence of <i>Clematis calcicola</i> J. S. Kim (Ranunculaceae) is 159,655 bp in length. It consists of large (79,451 bp) and small (18,126 bp) single-copy regions and a pair of identical inverted repeats (31,039 bp). The genome contains 92 protein-coding genes, 36 transfer RNA genes, eight ribosomal RNA genes, and two pseudogenes. A phylogenetic analysis based on the cp genome of 19 taxa showed high similarity between our cp genome and data published for <i>C. calcicola</i>, which is recognized as a species endemic to the Korean Peninsula. The complete cp genome sequence of <i>C. calcicola</i> reported here provides important information for future phylogenetic and evolutionary studies of Ranunculaceae.