Complete Chloroplast Genome Sequences of Clematis: IR Expansion and Relative Rates of Synonymous Substitutions

Genus Clematis is one of the largest within Ranunculaceae. Here we report the chloroplast genome of two Clematis species, C. brachyura and C. trichotoma endemic to Korea. The chloroplast genome lengths of C. brachyura and C. trichotoma are 159,532 bp and 159,170 bp, respectively. Gene contents in the complete chloroplast genomes of these two Clematis species are identical to that of most Ranunculaceae and other angiosperms. However, our data results demonstrated that genus Clematis has inversion and rearrangement events concerning gene rps4 gene, rps16 to trnH region, and trnL to ndhC region, and IR regions expansion. Comparison of IR regions among Ranunculaceae species revealed that Clematis species contained six protein coding genes (infA, rps8, rpl14, rpl16, rps3, and rpl22) usually found in the long single copy (LSC) region of other species. Phylogenetic analysis demonstrated that genus Clematis is closely related to genus Ranunculus. Differences in repeat structure, substitution rates, and IR expansion in genera Clematis and Ranunculus, explained their relationship. Clematis species showed slightly higher tandem repeats content than Ranunculus species. The six protein-coding genes showed lower synonymous substitution rates in the IR of Clematis species than in the LSC of Ranunculus species. Overall, the chloroplast genomes and results presented here provide important information on the evolution of Ranunculaceae.

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The complete chloroplast genome of Saxifraga sinomontana (Saxifragaceae) and comparative analysis with other Saxifragaceae species

Revista Brasileira de Botânica ◽

10.1007/s40415-019-00561-y ◽

2019 ◽

Vol 42 (4) ◽

pp. 601-611 ◽

Cited By ~ 1

Author(s):

Yan Li ◽

Liukun Jia ◽

Zhihua Wang ◽

Rui Xing ◽

Xiaofeng Chi ◽

...

Keyword(s):

Comparative Analysis ◽

Chloroplast Genome ◽

Phylogenetic Relationships ◽

De Novo ◽

Single Copy ◽

Bootstrap Support ◽

Protein Coding ◽

Complete Chloroplast Genome ◽

Protein Coding Genes ◽

Chloroplast Genomes

Abstract Saxifraga sinomontana J.-T. Pan & Gornall belongs to Saxifraga sect. Ciliatae subsect. Hirculoideae, a lineage containing ca. 110 species whose phylogenetic relationships are largely unresolved due to recent rapid radiations. Analyses of complete chloroplast genomes have the potential to significantly improve the resolution of phylogenetic relationships in this young plant lineage. The complete chloroplast genome of S. sinomontana was de novo sequenced, assembled and then compared with that of other six Saxifragaceae species. The S. sinomontana chloroplast genome is 147,240 bp in length with a typical quadripartite structure, including a large single-copy region of 79,310 bp and a small single-copy region of 16,874 bp separated by a pair of inverted repeats (IRs) of 25,528 bp each. The chloroplast genome contains 113 unique genes, including 79 protein-coding genes, four rRNAs and 30 tRNAs, with 18 duplicates in the IRs. The gene content and organization are similar to other Saxifragaceae chloroplast genomes. Sixty-one simple sequence repeats were identified in the S. sinomontana chloroplast genome, mostly represented by mononucleotide repeats of polyadenine or polythymine. Comparative analysis revealed 12 highly divergent regions in the intergenic spacers, as well as coding genes of matK, ndhK, accD, cemA, rpoA, rps19, ndhF, ccsA, ndhD and ycf1. Phylogenetic reconstruction of seven Saxifragaceae species based on 66 protein-coding genes received high bootstrap support values for nearly all identified nodes, suggesting a promising opportunity to resolve infrasectional relationships of the most species-rich section Ciliatae of Saxifraga.

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Two Korean Endemic Clematis Chloroplast Genomes: Inversion, Reposition, Expansion of the Inverted Repeat Region, Phylogenetic Analysis, and Nucleotide Substitution Rates

Plants ◽

10.3390/plants10020397 ◽

2021 ◽

Vol 10 (2) ◽

pp. 397

Author(s):

Kyoung Su Choi ◽

Young-Ho Ha ◽

Hee-Young Gil ◽

Kyung Choi ◽

Dong-Kap Kim ◽

...

Keyword(s):

Phylogenetic Analysis ◽

Inverted Repeat ◽

Nonsynonymous Substitution ◽

Single Copy ◽

Inverted Repeat Region ◽

Substitution Rates ◽

Protein Coding ◽

Protein Coding Genes ◽

Chloroplast Genomes ◽

Fundamental Information

Previous studies on the chloroplast genome in Clematis focused on the chloroplast structure within Anemoneae. The chloroplast genomes of Cleamtis were sequenced to provide information for studies on phylogeny and evolution. Two Korean endemic Clematis chloroplast genomes (Clematis brachyura and C. trichotoma) range from 159,170 to 159,532 bp, containing 134 identical genes. Comparing the coding and non-coding regions among 12 Clematis species revealed divergent sites, with carination occurring in the petD-rpoA region. Comparing other Clematis chloroplast genomes suggested that Clematis has two inversions (trnH-rps16 and rps4), reposition (trnL-ndhC), and inverted repeat (IR) region expansion. For phylogenetic analysis, 71 protein-coding genes were aligned from 36 Ranunculaceae chloroplast genomes. Anemoneae (Anemoclema, Pulsatilla, Anemone, and Clematis) clades were monophyletic and well-supported by the bootstrap value (100%). Based on 70 chloroplast protein-coding genes, we compared nonsynonymous (dN) and synonymous (dS) substitution rates among Clematis, Anemoneae (excluding Clematis), and other Ranunculaceae species. The average synonymoussubstitution rates (dS)of large single copy (LSC), small single copy (SSC), and IR genes in Anemoneae and Clematis were significantly higher than those of other Ranunculaceae species, but not the nonsynonymous substitution rates (dN). This study provides fundamental information on plastid genome evolution in the Ranunculaceae.

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Comparing Patterns of Nucleotide Substitution Rates Among Chloroplast Loci Using the Relative Ratio Test

Genetics ◽

10.1093/genetics/146.1.393 ◽

1997 ◽

Vol 146 (1) ◽

pp. 393-399 ◽

Cited By ~ 2

Author(s):

Spencer V Muse ◽

Brandon S Gaut

Keyword(s):

Nucleotide Substitution ◽

Nonsynonymous Substitution ◽

Synonymous Substitution ◽

Joint Analysis ◽

Ratio Test ◽

Substitution Rates ◽

Chloroplast Genomes ◽

Synonymous Substitution Rates ◽

Nucleotide Substitution Rates ◽

Evolutionary Lineages

Even when several genetic loci are used in molecular evolutionary studies, each locus is typically analyzed independently of the others. This type of approach makes it difficult to study mechanisms and processes that affect multiple genes. In this work we develop a statistical approach for the joint analysis of two or more loci. The tests we propose examine whether or not nucleotide substitution rates across evolutionary lineages have the same relative proportions at two loci. Theses procedures are applied to 33 genes from the chloroplast genomes of rice, tobacco, pine, and liverwort. With the exception of five clearly distinct loci, we find that synonymous substitution rates tend to change proportionally across genes. We interpret these results to be consistent with a “lineage effect” acting on the entire chloroplast genome. In contrast, nonsynonymous rates do not change proportionally across genes, suggesting that locus-specific evolutionary effects dominate patterns of nonsynonymous substitution.

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Comparative analysis of chloroplast genomes for five Dicliptera species (Acanthaceae): molecular structure, phylogenetic relationships, and adaptive evolution

PeerJ ◽

10.7717/peerj.8450 ◽

2020 ◽

Vol 8 ◽

pp. e8450 ◽

Cited By ~ 2

Author(s):

Sunan Huang ◽

Xuejun Ge ◽

Asunción Cano ◽

Betty Gaby Millán Salazar ◽

Yunfei Deng

Keyword(s):

Adaptive Evolution ◽

Phylogenetic Relationships ◽

Single Copy ◽

Rrna Genes ◽

Trna Genes ◽

Evolutionary Analysis ◽

Protein Coding ◽

Variable Regions ◽

Protein Coding Genes ◽

Chloroplast Genomes

The genus Dicliptera (Justicieae, Acanthaceae) consists of approximately 150 species distributed throughout the tropical and subtropical regions of the world. Newly obtained chloroplast genomes (cp genomes) are reported for five species of Dilciptera (D. acuminata, D. peruviana, D. montana, D. ruiziana and D. mucronata) in this study. These cp genomes have circular structures of 150,689–150,811 bp and exhibit quadripartite organizations made up of a large single copy region (LSC, 82,796–82,919 bp), a small single copy region (SSC, 17,084–17,092 bp), and a pair of inverted repeat regions (IRs, 25,401–25,408 bp). Guanine-Cytosine (GC) content makes up 37.9%–38.0% of the total content. The complete cp genomes contain 114 unique genes, including 80 protein-coding genes, 30 transfer RNA (tRNA) genes, and four ribosomal RNA (rRNA) genes. Comparative analyses of nucleotide variability (Pi) reveal the five most variable regions (trnY-GUA-trnE-UUC, trnG-GCC, psbZ-trnG-GCC, petN-psbM, and rps4-trnL-UUA), which may be used as molecular markers in future taxonomic identification and phylogenetic analyses of Dicliptera. A total of 55-58 simple sequence repeats (SSRs) and 229 long repeats were identified in the cp genomes of the five Dicliptera species. Phylogenetic analysis identified a close relationship between D. ruiziana and D. montana, followed by D. acuminata, D. peruviana, and D. mucronata. Evolutionary analysis of orthologous protein-coding genes within the family Acanthaceae revealed only one gene, ycf15, to be under positive selection, which may contribute to future studies of its adaptive evolution. The completed genomes are useful for future research on species identification, phylogenetic relationships, and the adaptive evolution of the Dicliptera species.

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Complete Chloroplast Genome of Argania spinosa: Structural Organization and Phylogenetic Relationships in Sapotaceae

Plants ◽

10.3390/plants9101354 ◽

2020 ◽

Vol 9 (10) ◽

pp. 1354

Author(s):

Slimane Khayi ◽

Fatima Gaboun ◽

Stacy Pirro ◽

Tatiana Tatusova ◽

Abdelhamid El Mousadik ◽

...

Keyword(s):

Chloroplast Genome ◽

Single Copy ◽

Rrna Genes ◽

Trna Genes ◽

Protein Coding ◽

Important Species ◽

Complete Chloroplast Genome ◽

Argania Spinosa ◽

Protein Coding Genes ◽

Cp Genome

Argania spinosa (Sapotaceae), an important endemic Moroccan oil tree, is a primary source of argan oil, which has numerous dietary and medicinal proprieties. The plant species occupies the mid-western part of Morocco and provides great environmental and socioeconomic benefits. The complete chloroplast (cp) genome of A. spinosa was sequenced, assembled, and analyzed in comparison with those of two Sapotaceae members. The A. spinosa cp genome is 158,848 bp long, with an average GC content of 36.8%. The cp genome exhibits a typical quadripartite and circular structure consisting of a pair of inverted regions (IR) of 25,945 bp in length separating small single-copy (SSC) and large single-copy (LSC) regions of 18,591 and 88,367 bp, respectively. The annotation of A. spinosa cp genome predicted 130 genes, including 85 protein-coding genes (CDS), 8 ribosomal RNA (rRNA) genes, and 37 transfer RNA (tRNA) genes. A total of 44 long repeats and 88 simple sequence repeats (SSR) divided into mononucleotides (76), dinucleotides (7), trinucleotides (3), tetranucleotides (1), and hexanucleotides (1) were identified in the A. spinosa cp genome. Phylogenetic analyses using the maximum likelihood (ML) method were performed based on 69 protein-coding genes from 11 species of Ericales. The results confirmed the close position of A. spinosa to the Sideroxylon genus, supporting the revisiting of its taxonomic status. The complete chloroplast genome sequence will be valuable for further studies on the conservation and breeding of this medicinally and culinary important species and also contribute to clarifying the phylogenetic position of the species within Sapotaceae.

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Phylogenetic Analysis and Substitution Rate Estimation of Colonial Volvocine Algae Based on Mitochondrial Genomes

Genes ◽

10.3390/genes11010115 ◽

2020 ◽

Vol 11 (1) ◽

pp. 115

Author(s):

Yuxin Hu ◽

Weiyue Xing ◽

Zhengyu Hu ◽

Guoxiang Liu

Keyword(s):

Phylogenetic Analysis ◽

Mitochondrial Genome ◽

Phylogenetic Relationship ◽

Phylogenetic Analyses ◽

Mitochondrial Protein ◽

Substitution Rates ◽

Protein Coding ◽

Protein Coding Genes ◽

Chloroplast Genomes ◽

Volvocine Algae

We sequenced the mitochondrial genome of six colonial volvocine algae, namely: Pandorina morum, Pandorina colemaniae, Volvulina compacta, Colemanosphaera angeleri, Colemanosphaera charkowiensi, and Yamagishiella unicocca. Previous studies have typically reconstructed the phylogenetic relationship between colonial volvocine algae based on chloroplast or nuclear genes. Here, we explore the validity of phylogenetic analysis based on mitochondrial protein-coding genes. We found phylogenetic incongruence of the genera Yamagishiella and Colemanosphaera. In Yamagishiella, the stochastic error and linkage group formed by the mitochondrial protein-coding genes prevent phylogenetic analyses from reflecting the true relationship. In Colemanosphaera, a different reconstruction approach revealed a different phylogenetic relationship. This incongruence may be because of the influence of biological factors, such as incomplete lineage sorting or horizontal gene transfer. We also analyzed the substitution rates in the mitochondrial and chloroplast genomes between colonial volvocine algae. Our results showed that all volvocine species showed significantly higher substitution rates for the mitochondrial genome compared with the chloroplast genome. The nonsynonymous substitution (dN)/synonymous substitution (dS) ratio is similar in the genomes of both organelles in most volvocine species, suggesting that the two counterparts are under a similar selection pressure. We also identified a few chloroplast protein-coding genes that showed high dN/dS ratios in some species, resulting in a significant dN/dS ratio difference between the mitochondrial and chloroplast genomes.

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The complete structure of the cucumber (Cucumis sativus L.) chloroplast genome: Its composition and comparative analysis

Cellular & Molecular Biology Letters ◽

10.2478/s11658-007-0029-7 ◽

2007 ◽

Vol 12 (4) ◽

Cited By ~ 24

Author(s):

Wojciech Pląder ◽

Yasushi Yukawa ◽

Masahiro Sugiura ◽

Stefan Malepszy

Keyword(s):

Chloroplast Genome ◽

Single Copy ◽

Trna Genes ◽

Inverted Repeat Region ◽

Cucumis Sativus L ◽

Stem Loop ◽

Protein Coding ◽

Chloroplast Genomes ◽

Trna Species ◽

Rrna Species

AbstractThe complete nucleotide sequence of the cucumber (C. sativus L. var. Borszczagowski) chloroplast genome has been determined. The genome is composed of 155,293 bp containing a pair of inverted repeats of 25,191 bp, which are separated by two single-copy regions, a small 18,222-bp one and a large 86,688-bp one. The chloroplast genome of cucumber contains 130 known genes, including 89 protein-coding genes, 8 ribosomal RNA genes (4 rRNA species), and 37 tRNA genes (30 tRNA species), with 18 of them located in the inverted repeat region. Of these genes, 16 contain one intron, and two genes and one ycf contain 2 introns. Twenty-one small inversions that form stem-loop structures, ranging from 18 to 49 bp, have been identified. Eight of them show similarity to those of other species, while eight seem to be cucumber specific. Detailed comparisons of ycf2 and ycf15, and the overall structure to other chloroplast genomes were performed.

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Complete Chloroplast Genome Sequence of Erigeron breviscapus and Characterization of Chloroplast Regulatory Elements

Frontiers in Plant Science ◽

10.3389/fpls.2021.758290 ◽

2021 ◽

Vol 12 ◽

Author(s):

Yifan Yu ◽

Zhen Ouyang ◽

Juan Guo ◽

Wen Zeng ◽

Yujun Zhao ◽

...

Keyword(s):

Chloroplast Genome ◽

Single Copy ◽

Regulatory Elements ◽

Rrna Genes ◽

Expression Vectors ◽

Protein Coding ◽

Protein Coding Genes ◽

Flanking Sequences ◽

Erigeron Breviscapus ◽

Cp Genome

Erigeron breviscapus is a famous medicinal plant. However, the limited chloroplast genome information of E. breviscapus, especially for the chloroplast DNA sequence resources, has hindered the study of E. breviscapus chloroplast genome transformation. Here, the complete chloroplast (cp) genome of E. breviscapus was reported. This genome was 152,164bp in length, included 37.2% GC content and was structurally arranged into two 24,699bp inverted repeats (IRs) and two single-copy areas. The sizes of the large single-copy region and the small single-copy region were 84,657 and 18,109bp, respectively. The E. breviscapus cp genome consisted of 127 coding genes, including 83 protein coding genes, 36 transfer RNA (tRNA) genes, and eight ribosomal RNA (rRNA) genes. For those genes, 95 genes were single copy genes and 16 genes were duplicated in two inverted regions with seven tRNAs, four rRNAs, and five protein coding genes. Then, genomic DNA of E. breviscapus was used as a template, and the endogenous 5' and 3' flanking sequences of the trnI gene and trnA gene were selected as homologous recombinant fragments in vector construction and cloned through PCR. The endogenous 5' flanking sequences of the psbA gene and rrn16S gene, the endogenous 3' flanking sequences of the psbA gene, rbcL gene, and rps16 gene and one sequence element from the psbN-psbH chloroplast operon were cloned, and certain chloroplast regulatory elements were identified. Two homologous recombination fragments and all of these elements were constructed into the cloning vector pBluescript SK (+) to yield a series of chloroplast expression vectors, which harbored the reporter gene EGFP and the selectable marker aadA gene. After identification, the chloroplast expression vectors were transformed into Escherichia coli and the function of predicted regulatory elements was confirmed by a spectinomycin resistance test and fluorescence intensity measurement. The results indicated that aadA gene and EGFP gene were efficiently expressed under the regulation of predicted regulatory elements and the chloroplast expression vector had been successfully constructed, thereby providing a solid foundation for establishing subsequent E. breviscapus chloroplast transformation system and genetic improvement of E. breviscapus.

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Characterization of the complete chloroplast genome sequence and phylogenetic analysis of B. oleracea var. italica

10.21203/rs.2.20976/v1 ◽

2020 ◽

Author(s):

Zhenchao Zhang ◽

Zhongliang Dai ◽

Yuemei Yao ◽

Yongfei Pan ◽

Guosheng Sun ◽

...

Keyword(s):

Chloroplast Genome ◽

Genome Sequence ◽

Genomic Structure ◽

Gc Content ◽

Single Copy ◽

Biological Research ◽

Protein Coding ◽

Protein Coding Genes ◽

Cp Genome ◽

Functional Components

Abstract Backgrounds: Broccoli (Brassica. oleracea var. italica L.) is known as one of the most nutritionally rich vegetables, as well as rich in functional components that benefit to health. The main purposes of this research were sequencing, assembling and annotation of chloroplast genome of broccoli based on Illumina HiSeq2500 sequencing platform. Results: The size of the broccoli cp genome is 153,364 bp, including two inverted repeat (IR) regions of 26,197 bp each, separated by a small single copy (SSC) region of 17,834 bp and a large single copy (LSC) region of 83,136 bp. The GC content of the complete genome is 36.36%, while those of SSC, LSC, and IR are 29.1%, 34.15% and 42.35%, respectively. It harbors 134 functional genes, including 87 protein-coding genes, 39 tRNAs and 8 rRNAs, with 31 duplicates in the IRs. The most abundant amino acid in the protein-coding genes is leucine, while the least is cysteine. Codon usage frequency showed bias for A/T-ending codons in the cp genome. In the repeat structure analysis, a total of 34 repeat sequences and 291 simple sequence repeat (SSRs) were detected in the work. Although cp genomic structure and size are highly conserved, the SC-IR boundary regions are variable between the 7 cp genomes. The phylogenetic relationships based on complete cp genome from 9 species suggest that B. oleracea var. italica is closely related to Brassica juncea. Conclusions: The complete cp genome sequence was obtained and annotated for broccoli for the first time. The information acquired from this research will be useful for further species identification, population genetics and biological research of broccoli.

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Analyzing and characterization of the chloroplast genome of Salix suchowensis

10.7287/peerj.preprints.2388 ◽

2016 ◽

Author(s):

Congrui Sun ◽

Jie Li ◽

Xiaogang Dai ◽

Yingnan Chen

Keyword(s):

Tandem Repeats ◽

Gene Annotation ◽

Repetitive Sequences ◽

Single Copy ◽

Phylogenetic Position ◽

Shrub Willow ◽

Protein Coding ◽

Protein Coding Genes ◽

Cp Genome ◽

Rna Genes

By screening sequence reads from the chloroplast (cp) genome of S. suchowensis that generated by the next generation sequencing platforms, we built the complete circular pseudomolecule for its cp genome. This pseudomolecule is 155,508 bp in length, which has a typical quadripartite structure containing two single copy regions, a large single copy region (LSC 84,385 bp), and a small single copy region (SSC 16,209 bp) separated by inverted repeat regions (IRs 27,457 bp). Gene annotation revealed that the cp genome of S. suchowensis encoded 119 unique genes, including 4 ribosome RNA genes, 30 transfer RNA genes, 82 protein-coding genes and 3 pseudogenes. Analyzing the repetitive sequences detected 15 tandem repeats, 16 forward repeats and 5 palindromic repeats. In addition, a total of 188 perfect microsatellites were detected, which were characterized as A/T predominance in nucleotide compositions. Significant shifting of the IR/SSC boundaries was revealed by comparing this cp genome with that of other rosids plants. We also built phylogenetic trees to demonstrate the phylogenetic position of S. suchowensis in Rosidae, with 66 orthologous protein-coding genes presented in the cp genomes of 32 species. By sequencing 30 amplicons based on the pseudomolecule, experimental verification achieved accuracy up to 99.84% for the cp genome assembly of S. suchowensis. In conclusion, this study built a high quality pseudomolecule for the cp genome of S. suchowensis, which is a useful resource for facilitating the development of this shrub willow into a more productive bioenergy crop.

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