Comparative Chloroplast Genome Analysis and Evolutionary Relationships in Some Species of Asclepiadeae, Apocynaceae

2021 ◽  
Author(s):  
Abidina Abba ◽  
Dhafer Alzahrani ◽  
Samaila Yaradua ◽  
Enas Albokhari
Keyword(s):  
Ssr Markers ◽  
Genome Structure ◽  
Single Copy ◽  
Medicinal Uses ◽  
Coding Regions ◽  
Circular Genome ◽  
Chloroplast Genomes ◽  
Genome Map ◽  
Small Single Copy ◽  
Gc Contents

Background: Comparative study of the complete chloroplast genomes of some species in the Subtribe Asclepiadeae was conducted to evaluate the variations and similarities between the species and to resolve the phylogenetic relationship within the subtribe. P. tomentosa has been used for medicinal uses in Saudi Arabia, Middle East, Africa and Brazil. It is used often in cosmetics and tanning industries, although it’s very well utilized as a traditional medicine in many civilizations.Methods: The genomes were compared using Mvista Bioinformatics tools to evaluate the inverted repeats (IR), large single copy (LSC) and small single copy (SSC) regions and also the border junctions were visualized with IR scope to express the expansion and contraction of the circular genome structure. While SSR markers were determined using the Reputer program, the genome map was done using OGDRAW (OrganellarGenomeDRAW).Result: Observed variations of the Mvista alignments is mainly at the coding regions of the sequences, while IR borders were varied at the SSC region of A. nivea genome; with ycf1 and rps19 due to evolutionary events. The genome sizes of C. procera are 166,010 bp, P. tomentosa 164,213bp, A. nivea 161,592 bp and C. wilfordii 161,180 bp. GC contents of A. nivea, C. wilfordii and P. tomentosa are 38% respectively; while C. procera is the least with 37%.; total SSR markers as well as the circular genome map were presented in this study.

scholarly journals Comparative and Phylogenetic Analysis of Complete Chloroplast Genomes in Eragrostideae (Chloridoideae, Poaceae)

Plants ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 109
Author(s):  
Kuan Liu ◽  
Rong Wang ◽  
Xiu-Xiu Guo ◽  
Xue-Jie Zhang ◽  
Xiao-Jian Qu ◽  
...  
Keyword(s):  
Phylogenetic Analysis ◽  
Genome Structure ◽  
Single Copy ◽  
Rrna Genes ◽  
Molecular Evidence ◽  
Trna Genes ◽  
Protein Coding ◽  
Hypervariable Regions ◽  
Chloroplast Genomes ◽  
Small Single Copy

Eragrostideae Stapf, the second-largest tribe in Chloridoideae (Poaceae), is a taxonomically complex tribe. In this study, chloroplast genomes of 13 Eragrostideae species were newly sequenced and used to resolve the phylogenetic relationships within Eragrostideae. Including seven reported chloroplast genomes from Eragrostideae, the genome structure, number and type of genes, codon usage, and repeat sequences of 20 Eragrostideae species were analyzed. The length of these chloroplast genomes varied from 130,773 bp to 135,322 bp. These chloroplast genomes showed a typical quadripartite structure, including a large single-copy region (77,993–80,643 bp), a small single-copy region (12,410–12,668 bp), and a pair of inverted repeats region (19,394–21,074 bp). There were, in total, 129–133 genes annotated in the genome, including 83–87 protein-coding genes, eight rRNA genes, and 38 tRNA genes. Forward and palindromic repeats were the most common repeat types. In total, 10 hypervariable regions (rpl22, rpoA, ndhF, matK, trnG–UCC-trnT–GGU, ndhF–rpl32, ycf4–cemA, rpl32–trnL–UAG, trnG–GCC–trnfM–CAU, and ccsA–ndhD) were found, which can be used as candidate molecular markers for Eragrostideae. Phylogenomic studies concluded that Enneapogon diverged first, and Eragrostis including Harpachne is the sister to Uniola. Furthermore, Harpachne harpachnoides is considered as a species of Eragrostis based on morphological and molecular evidence. In addition, the interspecies relationships within Eragrostis are resolved based on complete chloroplast genomes. This study provides useful chloroplast genomic information for further phylogenetic analysis of Eragrostideae.

scholarly journals The Chloroplast Genome Evolution of Venus Slipper (Paphiopedilum): IR Expansion, SSC Contraction, and Highly Rearranged SSC Regions

2021 ◽  
Author(s):  
Yan-Yan Guo ◽  
Jia-Xing Yang ◽  
Guo-Qiang Zhang ◽  
Zhong-Jian Liu
Keyword(s):  
Gene Order ◽  
Inverted Repeat ◽  
Genome Structure ◽  
Single Copy ◽  
Gene Content ◽  
Comparative Genomic ◽  
Plastome Evolution ◽  
Chloroplast Genomes ◽  
Ideal System ◽  
Small Single Copy

Abstract Background: Paphiopedilum is the largest genus of slipper orchids. Previous studies showed that the phylogenetic relationships of this genus are not well resolved, and sparse taxon sampling documented inverted repeat (IR) expansion and small single copy (SSC) contraction of the chloroplast genomes of Paphiopedilum. Here, we sequenced, assembled, and annotated 77 plastomes of Paphiopedilum species. The phylogeny based on the plastome resolved the relationships of the genus except for the phylogenetic position of two unstable species. We used phylogenetic and comparative genomic approaches to elucidate the plastome evolution of Paphiopedilum.Results: The plastomes of Paphiopedilum have conserved genome structure and gene content except in the SSC region. The large single copy/inverted repeat (LSC/IR) boundaries are relatively stable, while the boundaries of inverted repeat/small single copy (IR/SSC) boundaries varied among species. Corresponding to the IR/SSC boundary shifts, the chloroplast genomes of the genus experienced IR expansion and SSC contraction. The IR region incorporated one to six genes of the SSC region. Unexpectedly, great variation in the size, gene order, and gene content of the SSC regions was found, especially in the subg. Parvisepalum. Furthermore, Paphiopedilum provides evidence for the ongoing degradation of the ndh genes in the photoautotrophic plants. The estimated substitution rates of the protein coding genes show accelerated rates of evolution in clpP, psbH, and psbZ. Genes transferred to the IR region due to the boundary shift also have higher substitution rates.Conclusions: We found IR expansion and SSC contraction in the chloroplast genomes of Paphiopedilum with dense sampling, and the genus shows variation in the size, gene order, and gene content of the SSC region. This genus provides an ideal system to investigate the dynamics of plastome evolution.

scholarly journals Genetic variation and structure of complete chloroplast genome in alien monoecious and dioecious Amaranthus weeds

2021 ◽  
Author(s):  
Han Xu ◽  
Ning Xiang ◽  
Junhua Zhang ◽  
Yongjiang Zhang
Keyword(s):  
Genetic Variation ◽  
Chloroplast Genome ◽  
Genome Structure ◽  
Similar Species ◽  
Complete Chloroplast Genome ◽  
Coding Regions ◽  
Circular Genome ◽  
Chloroplast Genomes ◽  
Topological Tree ◽  
Monophyletic Branch

Abstract Amaranthus is a complex taxon with economic importance as well as harmful weeds. We studied the genetic variation and structure of the chloroplast genomes of 22 samples from 17 species of three subgenera. It was found that the length of the chloroplast genome of Amaranthus varied from 149,949 bp of A. polygonoides to 150,757 bp of A. albus. The frequencies of SNPs and InDels in chloroplast genomes were 1.79 % and 2.86 %, and the variation mainly occurred in the non-coding regions. The longest InDel was 387 bp, which occurred on ycf2, followed by 384 bp InDel on psbM-trnD. Two InDels in ndhE-I on the SSC make the three subgenera clearly distinguished. In LSC, SSC and IRs regions, there were four 30 bp forward and reverse repeats, and the repeats in SSC and LSC were in nearly opposite positions in circular genome structure, and almost divided the circular genome into symmetrical structures. In the topological tree constructed by chloroplast genome, species in subgen. Amaranthus and subgen. Acnida form monophyletic branches separately and cluster together. A. albus, A. blitoides and A. polygonoides were separated from subgen. Albersia, and the rest of subgen. Albersia were clustered into a monophyletic branch. The rpoC2, ycf1, ndhF-rpl32 were good at distinguishing most amaranths. The trnk-UUU-atpF, trnT-UGU-atpB, psbE-clpP, rpl14-rps19, and ndhF-D can distinguish several similar species. In general, the chloroplast genome is of certain value for the identification of the similar species of Amaranthus, which provides more evidence for clarifying the phylogenetic relationships within the genus.

scholarly journals Complete Chloroplast Genomes of Acanthochlamys bracteata (China) and Xerophyta (Africa) (Velloziaceae): Comparative Genomics and Phylogenomic Placement

2021 ◽  
Vol 12 ◽  
Author(s):  
Vincent Okelo Wanga ◽  
Xiang Dong ◽  
Millicent Akinyi Oulo ◽  
Elijah Mbandi Mkala ◽  
Jia-Xin Yang ◽  
...  
Keyword(s):  
Chloroplast Genome ◽  
Genome Structure ◽  
Single Copy ◽  
Average Score ◽  
African Species ◽  
Complete Chloroplast Genome ◽  
Coding Regions ◽  
Chloroplast Genomes ◽  
Genomic Characterization ◽  
Cp Genome

Acanthochlamys P.C. Kao is a Chinese endemic monotypic genus, whereas XerophytaJuss. is a genus endemic to Africa mainland, Arabian Peninsula and Madagascar with ca.70 species. In this recent study, the complete chloroplast genome of Acanthochlamys bracteata was sequenced and its genome structure compared with two African Xerophyta species (Xerophyta spekei and Xerophyta viscosa) present in the NCBI database. The genomes showed a quadripartite structure with their sizes ranging from 153,843 bp to 155,498 bp, having large single-copy (LSC) and small single-copy (SSC) regions divided by a pair of inverted repeats (IR regions). The total number of genes found in A. bracteata, X. spekei and X. viscosa cp genomes are 129, 130, and 132, respectively. About 50, 29, 28 palindromic, forward and reverse repeats and 90, 59, 53 simple sequence repeats (SSRs) were found in the A. bracteata, X. spekei, and X. viscosa cp genome, respectively. Nucleotide diversity analysis in all species was 0.03501, Ka/Ks ratio average score was calculated to be 0.26, and intergeneric K2P value within the Order Pandanales was averaged to be 0.0831. Genomic characterization was undertaken by comparing the genomes of the three species of Velloziaceae and it revealed that the coding regions were more conserved than the non-coding regions. However, key variations were noted mostly at the junctions of IRs/SSC regions. Phylogenetic analysis suggests that A. bracteata species has a closer genetic relationship to the genus Xerophyta. The present study reveals the complete chloroplast genome of A. bracteata and gives a genomic comparative analysis with the African species of Xerophyta. Thus, can be useful in developing DNA markers for use in the study of genetic variabilities and evolutionary studies in Velloziaceae.

scholarly journals The chloroplast genome evolution of Venus slipper (Paphiopedilum): IR expansion, SSC contraction, and highly rearranged SSC regions

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Yan-Yan Guo ◽  
Jia-Xing Yang ◽  
Ming-Zhu Bai ◽  
Guo-Qiang Zhang ◽  
Zhong-Jian Liu
Keyword(s):  
Gene Order ◽  
Inverted Repeat ◽  
Single Copy ◽  
Gene Content ◽  
Comparative Genomic ◽  
Substitution Rates ◽  
Plastome Evolution ◽  
Chloroplast Genomes ◽  
Ideal System ◽  
Small Single Copy

Abstract Background Paphiopedilum is the largest genus of slipper orchids. Previous studies showed that the phylogenetic relationships of this genus are not well resolved, and sparse taxon sampling documented inverted repeat (IR) expansion and small single copy (SSC) contraction of the chloroplast genomes of Paphiopedilum. Results Here, we sequenced, assembled, and annotated 77 plastomes of Paphiopedilum species (size range of 152,130 – 164,092 bp). The phylogeny based on the plastome resolved the relationships of the genus except for the phylogenetic position of two unstable species. We used phylogenetic and comparative genomic approaches to elucidate the plastome evolution of Paphiopedilum. The plastomes of Paphiopedilum have a conserved genome structure and gene content except in the SSC region. The large single copy/inverted repeat (LSC/IR) boundaries are relatively stable, while the boundaries of the inverted repeat and small single copy region (IR/SSC) varied among species. Corresponding to the IR/SSC boundary shifts, the chloroplast genomes of the genus experienced IR expansion and SSC contraction. The IR region incorporated one to six genes of the SSC region. Unexpectedly, great variation in the size, gene order, and gene content of the SSC regions was found, especially in the subg. Parvisepalum. Furthermore, Paphiopedilum provides evidence for the ongoing degradation of the ndh genes in the photoautotrophic plants. The estimated substitution rates of the protein coding genes show accelerated rates of evolution in clpP, psbH, and psbZ. Genes transferred to the IR region due to the boundary shift also have higher substitution rates. Conclusions We found IR expansion and SSC contraction in the chloroplast genomes of Paphiopedilum with dense sampling, and the genus shows variation in the size, gene order, and gene content of the SSC region. This genus provides an ideal system to investigate the dynamics of plastome evolution.

scholarly journals A Circular Chloroplast Genome of Fagus sylvatica Reveals High Conservation between Two Individuals from Germany and One Individual from Poland and an Alternate Direction of the Small Single-Copy Region

Forests ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 180
Author(s):  
Bagdevi Mishra ◽  
Bartosz Ulaszewski ◽  
Sebastian Ploch ◽  
Jaroslaw Burczyk ◽  
Marco Thines
Keyword(s):  
Chloroplast Genome ◽  
Fagus Sylvatica ◽  
Pollen Dispersal ◽  
European Beech ◽  
Single Copy ◽  
Migration History ◽  
Chloroplast Genomes ◽  
Long Read ◽  
The Individual ◽  
Small Single Copy

Chloroplasts are difficult to assemble because of the presence of large inverted repeats. At the same time, correct assemblies are important, as chloroplast loci are frequently used for biogeography and population genetics studies. In an attempt to elucidate the orientation of the single-copy regions and to find suitable loci for chloroplast single nucleotide polymorphism (SNP)-based studies, circular chloroplast sequences for the ultra-centenary reference individual of European Beech (Fagus sylvatica), Bhaga, and an additional Polish individual (named Jamy) was obtained based on hybrid assemblies. The chloroplast genome of Bhaga was 158,458 bp, and that of Jamy was 158,462 bp long. Using long-read mapping on the configuration inferred in this study and the one suggested in a previous study, we found an inverted orientation of the small single-copy region. The chloroplast genome of Bhaga and of the individual from Poland both have only two mismatches as well as three and two indels as compared to the previously published genome, respectively. The low divergence suggests low seed dispersal but high pollen dispersal. However, once chloroplast genomes become available from Pleistocene refugia, where a high degree of variation has been reported, they might prove useful for tracing the migration history of Fagus sylvatica in the Holocene.

scholarly journals Long-reads reveal that the chloroplast genome exists in two distinct versions in most plants

2019 ◽  
Author(s):  
Weiwen Wang ◽  
Robert Lanfear
Keyword(s):  
Chloroplast Genome ◽  
Genome Structure ◽  
Single Copy ◽  
Land Plant ◽  
Inverted Repeats ◽  
Individual Plant ◽  
Single Individual ◽  
Equal Frequency ◽  
Flip Flop ◽  
Chloroplast Genomes

Abstract The chloroplast genome usually has a quadripartite structure consisting of a large single copy region and a small single copy region separated by two long inverted repeats. It has been known for some time that a single cell may contain at least two structural haplotypes of this structure, which differ in the relative orientation of the single copy regions. However, the methods required to detect and measure the abundance of the structural haplotypes are labour-intensive, and this phenomenon remains understudied. Here we develop a new method, Cp-hap, to detect all possible structural haplotypes of chloroplast genomes of quadripartite structure using long-read sequencing data. We use this method to conduct a systematic analysis and quantification of chloroplast structural haplotypes in 61 land plant species across 19 orders of Angiosperms, Gymnosperms and Pteridophytes. Our results show that there are two chloroplast structural haplotypes which occur with equal frequency in most land plant individuals. Nevertheless, species whose chloroplast genomes lack inverted repeats or have short inverted repeats have just a single structural haplotype. We also show that the relative abundance of the two structural haplotypes remains constant across multiple samples from a single individual plant, suggesting that the process which maintains equal frequency of the two haplotypes operates rapidly, consistent with the hypothesis that flip-flop recombination mediates chloroplast structural heteroplasmy. Our results suggest that previous claims of differences in chloroplast genome structure between species may need to be revisited.

scholarly journals Complete chloroplast genome sequences of Dioscorea: Characterization, genomic resources, and phylogenetic analyses

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e6032 ◽  
Author(s):  
Zhenyu Zhao ◽  
Xin Wang ◽  
Yi Yu ◽  
Subo Yuan ◽  
Dan Jiang ◽  
...  
Keyword(s):  
Chloroplast Genome ◽  
Phylogenetic Analyses ◽  
Single Copy ◽  
Genome Sequences ◽  
Complete Chloroplast Genome ◽  
Genomic Resources ◽  
Chloroplast Genomes ◽  
The Family ◽  
Small Single Copy

Dioscorea L., the largest genus of the family Dioscoreaceae with over 600 species, is not only an important food but also a medicinal plant. The identification and classification of Dioscorea L. is a rather difficult task. In this study, we sequenced five Dioscorea chloroplast genomes, and analyzed with four other chloroplast genomes of Dioscorea species from GenBank. The Dioscorea chloroplast genomes displayed the typical quadripartite structure of angiosperms, which consisted of a pair of inverted repeats separated by a large single-copy region, and a small single-copy region. The location and distribution of repeat sequences and microsatellites were determined, and the rapidly evolving chloroplast genome regions (trnK-trnQ, trnS-trnG, trnC-petN, trnE-trnT, petG-trnW-trnP, ndhF, trnL-rpl32, and ycf1) were detected. Phylogenetic relationships of Dioscorea inferred from chloroplast genomes obtained high support even in shortest internodes. Thus, chloroplast genome sequences provide potential molecular markers and genomic resources for phylogeny and species identification.

scholarly journals Seven Complete Chloroplast Genomes from Symplocos: Genome Organization and Comparative Analysis

Forests ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 608
Author(s):  
Sang-Chul Kim ◽  
Jei-Wan Lee ◽  
Byoung-Ki Choi
Keyword(s):  
Chloroplast Genome ◽  
Single Copy ◽  
Rrna Genes ◽  
Trna Genes ◽  
Coding Regions ◽  
Chloroplast Genomes ◽  
Ion Torrent Sequencing ◽  
Species Specific ◽  
Taxonomic Characterization

In the present study, chloroplast genome sequences of four species of Symplocos (S. chinensis for. pilosa, S. prunifolia, S. coreana, and S. tanakana) from South Korea were obtained by Ion Torrent sequencing and compared with the sequences of three previously reported Symplocos chloroplast genomes from different species. The length of the Symplocos chloroplast genome ranged from 156,961 to 157,365 bp. Overall, 132 genes including 87 functional genes, 37 tRNA genes, and eight rRNA genes were identified in all Symplocos chloroplast genomes. The gene order and contents were highly similar across the seven species. The coding regions were more conserved than the non-coding regions, and the large single-copy and small single-copy regions were less conserved than the inverted repeat regions. We identified five new hotspot regions (rbcL, ycf4, psaJ, rpl22, and ycf1) that can be used as barcodes or species-specific Symplocos molecular markers. These four novel chloroplast genomes provide basic information on the plastid genome of Symplocos and enable better taxonomic characterization of this genus.

scholarly journals Comparative chloroplast genomics of Fritillaria (Liliaceae), inferences for phylogenetic relationships between Fritillaria and Lilium and genome evolution

2019 ◽  
Author(s):  
Jiao Huang ◽  
Yan Yu ◽  
Yan-Mei Liu ◽  
Deng-Feng Xie ◽  
Xing-Jin He ◽  
...  
Keyword(s):  
Phylogenetic Relationships ◽  
New World ◽  
Genome Structure ◽  
Single Copy ◽  
Phylogenomic Analysis ◽  
Structural Variations ◽  
Weak Support ◽  
Hypervariable Regions ◽  
Chloroplast Genomes ◽  
Gene Data

Abstract Background Fritillaria is a genus consisting of about 140 species that has important medicinal and horticultural values. The monophyly of Fritillaria and phylogenetic relationships with Lilium were previously not fully resolved. The study involved the most comprehensive chloroplast genomes samples to date referring to Old and New World clades of Fritillaria as identified in earlier studies.Results We reported and compared eleven newly sequenced whole-plastome sequences of Fritillaria as well as characterization of SSRs and repeat sequence. These 11 plastomes proved highly similar in overall size (151,652-152,434bp), genome structure, gene content and order; Comparing them with other species of Liliales (6 out of 10 families) indicated the same similarity but showed some structural variations due to the contraction or expansion of the IR regions out or into of adjacent single-copy regions. A/T mononucleotides, palindromic and forward repeats were the most common types. Six hypervariable regions ( rps16 - trnQ, rbcL - accD, accD - psaI, psaJ - rpl33, petD - rpoA and rpl32 - trnL ) were discovered based on 26 Fritillaria whole-plastomes to be potential molecular markers. 26 species of Fritillaria plastomes and 21 species of Lilium plastomes were combined in a phylogenomic study with 3 Cardiocrinum species as out groups. Fritillaria was monophyly with moderate support as sister to Lilium based on 64 protein-coding genes (CDS) and the interspecific relationship within subgenus Fritillaria has strong resolution. The topology recovered from the whole plastome and single-copy gene data sets was the same as for coding gene data, but weak support for monophyly of Fritillaria .Conclusions The phylogenomic analysis reconstructed a topology that had some incongruences with previous studies. The six hypervariable regions can be used as candidate DNA barcodes for global genetic diversity detection of Fritillaria . The phylogenomic framework from this study can guide extensive genomic sampling to further discern the relationships among the Old and New World clades of Fritillaria and Lilium .

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