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1.
Ardisia is a basal asterid genus well known for its medicinal values and has the potential for development of novel phytopharmaceuticals. In this genus of nearly 500 species, many ornamental species are commonly grown worldwide and some have become invasive species that caused ecological problems. As there is no completed plastid genome (plastome) sequence in related taxa, we sequenced and characterized the plastome of Ardisia polysticta to find plastid markers of potential utility for phylogenetic analyses at low taxonomic levels. The complete A. polysticta plastome is 156,506 bp in length and has gene content and organization typical of most asterids and other angiosperms. We identified seven intergenic regions as potentially informative markers with resolution for interspecific relationships. Additionally, we characterized the diversity of asterid plastomes with respect to GC content, plastome organization, gene content, and repetitive sequences through comparative analyses. The results demonstrated that the genome organizations near the boundaries between inverted repeats (IRs) and single-copy regions (SCs) are polymorphic. The boundary organization found in Ardisia appears to be the most common type among asterids, while six other types are also found in various asterid lineages. In general, the repetitive sequences in genic regions tend to be more conserved, whereas those in noncoding regions are usually lineage-specific. Finally, we inferred the whole-plastome phylogeny with the available asterid sequences. With the improvement in taxon sampling of asterid orders and families, our result highlights the uncertainty of the position of Gentianales within euasterids I.  相似文献   

2.
Magnolia grandiflora is an important medicinal,ornamental and horticultural plant species.The chloroplast(cp) genome of M.grandiflora was sequenced using a 454 sequencing platform and the genome structure was compared with other related species.The complete cp genome of M.grandiflora was 159623 bp in length and contained a pair of inverted repeats(IR) of 26563 bp separated by large and small single copy(LSC,SSC) regions of 87757 and 18740 bp,respectively.A total of 129 genes were successfully annotated,18 of which included introns.The identity,number and GC content of M.grandiflora cp genes were similar to those of other Magnoliaceae species genomes.Analysis revealed 218 simple sequence repeat(SSR) loci,most composed of A or T,contributing to a bias in base composition.The types and abundances of repeat units in Magnoliaceae species were relatively conserved and these loci will be useful for developing M.grandiflora cp genome vectors.In addition,results indicated that the cp genome size in Magnoliaceae species and the position of the IR border were closely related to the length of the ycf1 gene.Phylogenetic analyses based on 66 shared genes from 30 species using maximum parsimony(MP) and maximum likelihood(ML) methods provided strong support for the phylogenetic position of Magnolia.The availability of the complete cp genome sequence of M.grandiflora provides valuable information for breeding of desirable varieties,cp genetic engineering,developing useful molecular markers and phylogenetic analyses in Magnoliaceae.  相似文献   

3.
Burmanniaceae is one major group within the monocot order Dioscoreales that has not had its plastome sequenced. Members of Burmanniaceae are mostly achlorophyllous, although the genus Burmannia also includes autotrophs. Here, we report sequencing and analysis of the first Burmanniaceae plastid genome from Burmannia disticha L.. This plastome is 157,480 bp and was assembled as a circular sequence with the typical quadripartite structure of plant plastid genomes. This plastome has a regular number of potentially functional genes with a total of 111, including 78 protein coding genes, 4 ribosomal RNA (rRNA) genes, and 29 tRNA genes. The ratio of the total length of genic:intergenic DNA is 1.58:1, and the mean length of intergenic regions is 398 bp, the longest being 1918 bp. The overall GC content of the B. disticha plastome is 34.90%, and the IR regions in B. disticha are more GC rich (39.50%) than the LSC (32.30%) and SSC (28.80%) regions. Phylogenetic analysis of protein-coding sequences from plastomes of related species in the order Dioscoreales support a clade comprising Burmanniaceae and Dioscoreaceae. This phylogenetic placement is congruent with previous findings based on nuclear and mitochondrial evidence.  相似文献   

4.
Eugenia uniflora is a plant native to tropical America that holds great ecological and economic importance. The complete chloroplast (cp) genome sequence of Eugenia uniflora, a member of the Neotropical Myrtaceae family, is reported here. The genome is 158,445 bp in length and exhibits a typical quadripartite structure of the large (LSC, 87,459 bp) and small (SSC, 18,318 bp) single-copy regions, separated by a pair of inverted repeats (IRs, 26,334 bp). It contains 111 unique genes, including 77 protein-coding genes, 30 tRNAs and 4 rRNAs. The genome structure, gene order, GC content and codon usage are similar to the typical angiosperm cp genomes. Comparison of the entire cp genomes of E. uniflora L. and three other Myrtaceae revealed an expansion of 43 bp in the intergenic spacer located between the IRA/large single-copy (LSC) border and the first gene of LSC region. Simple sequence repeat (SSR) analysis revealed that most SSRs are AT rich, which contribute to the overall AT richness of the cp genome. Additionally, fewer SSRs are distributed in the protein-coding sequences compared to the noncoding regions. Phylogenetic analysis among 58 species based on 57 cp genes demonstrated a closer relationship between E. uniflora L. and Syzygium cumini (L). Skeels compared to the Eucalyptus clade in the Myrtaceae family. The complete cp genome sequence of E. uniflora reported here has importance for population genetics, as well as phylogenetic and evolutionary studies in this species and other Myrtaceae species from Neotropical regions.  相似文献   

5.
Datura stramonium is a widely used poisonous plant with great medicinal and economic value. Its chloroplast (cp) genome is 155,871 bp in length with a typical quadripartite structure of the large (LSC, 86,302 bp) and small (SSC, 18,367 bp) single-copy regions, separated by a pair of inverted repeats (IRs, 25,601 bp). The genome contains 113 unique genes, including 80 protein-coding genes, 29 tRNAs and four rRNAs. A total of 11 forward, 9 palindromic and 13 tandem repeats were detected in the D. stramonium cp genome. Most simple sequence repeats (SSR) are AT-rich and are less abundant in coding regions than in non-coding regions. Both SSRs and GC content were unevenly distributed in the entire cp genome. All preferred synonymous codons were found to use A/T ending codons. The difference in GC contents of entire genomes and of the three-codon positions suggests that the D. stramonium cp genome might possess different genomic organization, in part due to different mutational pressures. The five most divergent coding regions and four non-coding regions (trnH-psbA, rps4-trnS, ndhD-ccsA, and ndhI-ndhG) were identified using whole plastome alignment, which can be used to develop molecular markers for phylogenetics and barcoding studies within the Solanaceae. Phylogenetic analysis based on 68 protein-coding genes supported Datura as a sister to Solanum. This study provides valuable information for phylogenetic and cp genetic engineering studies of this poisonous and medicinal plant.  相似文献   

6.
Panax stipuleanatus (Araliaceae) is an endangered and medicinally important plant endemic to China. However, phylogenetic relationships within the genus Panax have remained unclear. In this study, we sequenced the complete plastome of P. stipuleanatus and included previously reported Panax plastomes to better understand the relationships between species and plastome evolution within the genus Panax. The plastome of P. stipuleanatus is 156,069 base pairs (bp) in length, consisting of a pair of inverted repeats (IRs, each 25,887 bp) that divide the plastome into a large single copy region (LSC, 86,126 bp) and a small single copy region (SSC, 8169 bp). The plastome contains 114 unigenes (80 protein-coding genes, 30 tRNA genes, and 4 rRNA genes). Comparative analyses indicated that the plastome gene content and order, as well as the expansion/contraction of the IR regions, are all highly conserved within Panax. No significant positive selection in the plastid protein-coding genes was observed across the eight Panax species, suggesting the Panax plastomes may have undergone a strong purifying selection. Our phylogenomic analyses resulted in a phylogeny with high resolution and supports for Panax. Nine proteincoding genes and 10 non-coding regions presented high sequence divergence, which could be useful for identifying different Panax species.  相似文献   

7.
Although past studies have included Passiflora among angiosperm lineages with highly rearranged plastid genomes (plastomes), knowledge about plastome organization in the genus is limited. So far only one draft and one complete plastome have been published. Expanded sampling of Passiflora plastomes is needed to understand the extent of the genomic rearrangement in the genus, which is also unusual in having biparental plastid inheritance and plastome‐genome incompatibility. We sequenced 15 Passiflora plastomes using either Illumina paired‐end or shotgun cloning and Sanger sequencing approaches. Assembled plastomes were annotated using Dual Organellar GenoMe Annotator (DOGMA) and tRNAscan‐SE. The Populus trichocarpa plastome was used as a reference to estimate genomic rearrangements in Passiflora by performing whole genome alignment in progressiveMauve. The phylogenetic distribution of rearrangements was plotted on the maximum likelihood tree generated from 64 plastid encoded protein genes. Inverted repeat (IR) expansion/contraction and loss of the two largest hypothetical open reading frames, ycf1 and ycf2, account for most plastome size variation, which ranges from 139 262 base pairs (bp) in P. biflora to 161 494 bp in P. pittieri. Passiflora plastomes have experienced numerous inversions, gene and intron losses along with multiple independent IR expansions and contractions resulting in a distinct organization in each of the three subgenera examined. Each Passiflora subgenus has a unique plastome structure in terms of gene content, order and size. The phylogenetic distribution of rearrangements shows that Passiflora has experienced widespread genomic changes, suggesting that such events may not be reliable phylogenetic markers.  相似文献   

8.
The chloroplast genome of Pyrus was found to be 159,922?bp in length which included a pair of inverted repeats (IRs) of 26,392?bp, separated by a small single-copy region of 19,237?bp and a large single-copy region (LSC) of 87,901?bp. A total of 130 predicted genes (113 unique genes and 17 genes, which were duplicated in the IR) including 79 protein-coding genes, four ribosomal RNA genes and 30 tRNA genes were identified based on similarity to homologs from the chloroplast genome of Nicotiana tabacum. Genome organization was very similar to the inferred ancestral angiosperm chloroplast genome. Comparisons between Pyrus, Malus, and Prunus in Rosaceae revealed 220 indels (??10?bp). Excluding ycf1 and ycf2, which contained deletions in the coding region, all of these were detected in the spacer or intron regions. Three insertions and 13 deletions were detected in Pyrus compared to the same loci in Malus and Prunus. After comparing 89 noncoding chloroplast DNA regions in Pyrus and Malus, highly variable regions such as ndhC-trnV and trnR-atpA were identified. In Pyrus and Malus, the IR/LSC borders were 62?bp shorter than those of Prunus. In addition, there were length mutations at the IRa/LSC junction and in trnH. A total of 67 simple sequence repeats (more than 10 repeated motifs) were identified in the Pyrus chloroplast genome. The indels and simple sequence repeats will be useful evolutionary tools at both intra- and interspecific levels. Phylogenetic analysis demonstrated a close relationship between Pyrus and Prunus in the Rosaceae.  相似文献   

9.
苹果叶绿体基因组特征分析   总被引:2,自引:0,他引:2  
苹果(Malus×domestica)是最重要的温带水果之一。为了能更好的了解本种的分子生物学基础.对已发布的苹果叶绿体全基因组序列进行了结构特征分析。结果显示苹果的叶绿体基因组全长为160068bp,具有典型的被子植物叶绿体基因组的环状四分体结构,包含大单拷贝区(LSC),小单拷贝区(SSC)和两个反向互补重复区(IRs),长度分别为88184bp,19180bp和26352bp。基因组共有135个基因(20个基因分布在反向互补重复区,因此整个基因组包含115个不同的基因)。按照功能进行分类,这115个基因包括81个蛋白质编码基因,4个rRNA编码基因和30个tRNA基因。其中,ycf15.ycf68和infA三个基因包含多个终止密码子,推测可能为假基因。苹果的基因组结构.基因顺序.GC含量和密码子使用偏好均与典型的被子植物叶绿体基因组类似。在苹果的叶绿体基因组中,共检测到30个大于30bp的重复序列,其中包括21串联重复,6个正向重复和3个反向重复序列;并检测到237个简单重复序列(SSR)位点,大部分的SSR位点都偏向于A或者T组成。此外,每10000bp非编码区平均分布有24个SSR位点,而编码区平均有5个SSR位点,表明SSRs在叶绿体基因组上的分布是不均匀的。本文对苹果叶绿体基因组序列特征的报道,将有助于促进该种的居群遗传学、系统发育和叶绿体基因工程的研究。  相似文献   

10.
Although there is growing interest to take genomics into the complex realms of natural populations, there is a general shortage of genomic resources and tools available for wild species. This applies not at least to birds, for which genomic approaches should be helpful to questions such as adaptation, speciation and population genetics. In this study, we describe a genome-wide reference set of conserved avian gene markers, broadly applicable across birds. By aligning protein-coding sequences from the recently assembled chicken genome with orthologous sequences in zebra finch, we identified particularly conserved exonic regions flanking introns of suitable size for subsequent amplification and sequencing. Primers were designed for 242 gene markers evenly distributed across the chicken genome, with a mean inter-marker interval of 4.2 Mb. Between 78% and 93% of the markers amplified a specific product in five species tested (chicken, peregrine falcon, collared flycatcher, great reed warbler and blue tit). Two hundred markers were sequenced in collared flycatcher, yielding a total of 122.41 kb of genomic DNA sequence (12096 bp coding sequence and 110 314 bp noncoding). Intron size of collared flycatcher and chicken was highly correlated, as was GC content. A polymorphism screening using these markers in a panel of 10 unrelated collared flycatchers identified 871 single nucleotide polymorphisms (pi = 0.0029) and 33 indels (mainly very short). Avian genome characteristics such as uniform genome size and low rate of syntenic rearrangements suggest that this marker set will find broad utility as a genome-wide reference resource for molecular ecological and population genomic analysis of birds. We envision that it will be particularly useful for obtaining large-scale orthologous targets in different species--important in, for instance, phylogenetics--and for large-scale identification of evenly distributed single nucleotide polymorphisms needed in linkage mapping or in studies of gene flow and hybridization.  相似文献   

11.
Praxelis (Eupatorium catarium Veldkamp) is a new hazardous invasive plant species that has caused serious economic losses and environmental damage in the Northern hemisphere tropical and subtropical regions. Although previous studies focused on detecting the biological characteristics of this plant to prevent its expansion, little effort has been made to understand the impact of Praxelis on the ecosystem in an evolutionary process. The genetic information of Praxelis is required for further phylogenetic identification and evolutionary studies. Here, we report the complete Praxelis chloroplast (cp) genome sequence. The Praxelis chloroplast genome is 151,410 bp in length including a small single-copy region (18,547 bp) and a large single-copy region (85,311 bp) separated by a pair of inverted repeats (IRs; 23,776 bp). The genome contains 85 unique and 18 duplicated genes in the IR region. The gene content and organization are similar to other Asteraceae tribe cp genomes. We also analyzed the whole cp genome sequence, repeat structure, codon usage, contraction of the IR and gene structure/organization features between native and invasive Asteraceae plants, in order to understand the evolution of organelle genomes between native and invasive Asteraceae. Comparative analysis identified the 14 markers containing greater than 2% parsimony-informative characters, indicating that they are potential informative markers for barcoding and phylogenetic analysis. Moreover, a sister relationship between Praxelis and seven other species in Asteraceae was found based on phylogenetic analysis of 28 protein-coding sequences. Complete cp genome information is useful for plant phylogenetic and evolutionary studies within this invasive species and also within the Asteraceae family.  相似文献   

12.
Gastrodia longistyla, a new species of Orchidaceae from Yunnan Province, China, is described and illustrated. It is morphologically similar to Gastrodia peichatieniana, but can be easily distinguished from the latter by having a rhombic epichile, long column (6.0–7.5 mm long), and a needle-shaped appendage (1.8–3.2 mm in length) at the base of the stigma. Identification key and colour photographs are provided. A preliminary risk-of-extinction assessment, according to the IUCN Red List Categories and Criteria, is given for the new species. The plastome of G. longistyla is 30464 bp in length with GC content approximately 24.8%, and the plastome does not contain some housekeeping genes, such as matK, rpl16, or all photosynthesis genes. In addition, the G. longistyla plastome lacks an IR region. This indicates that the plastome is in the last stage of degradation.  相似文献   

13.
In this paper, we describe the complete chloroplast genome of Lolium arundinaceum. This sequence is the culmination of a long-term project completed by >400 undergraduates who took general genetics at Middle Tennessee State University from 2004-2007. It was undertaken in an attempt to introduce these students to an open-ended experiential/exploratory lesson to produce and analyze novel data. The data they produced should provide the necessary information for both phylogenetic comparisons and plastome engineering of tall fescue. The fescue plastome (GenBank FJ466687) is 136048 bp with a typical quadripartite structure and a gene order similar to other grasses; 56% of the plastome is coding region comprised of 75 protein-coding genes, 29 tRNAs, four rRNAs, and one hypothetical coding region (ycf). Comparisons of Poaceae plastomes reveal size differences between the PACC (subfamilies Panicoideae, Arundinoideae, Centothecoideae, and Chloridoideae) and BOP (subfamilies Bambusoideae, Oryzoideae, and Pooideae) clades. Alignment analysis suggests that several potentially conserved large deletions in previously identified intergenic length polymorphic regions are responsible for the majority of the size discrepancy. Phylogenetic analysis using whole plastome data suggests that fescue closely aligns with Lolium perenne. Some unique features as well as phylogenetic branch length calculations, however, suggest that a number of changes have occurred since these species diverged.  相似文献   

14.
Comparison of the Dendrosicyos socotranus and Corallocarpus boehmii (tribe Coniandreae, family Cucurbitaceae) plastome data was of interest. Data on RNA, tRNA, GC%, plastome size, CDS and pseudogene were tabulated for the two species. The total length of 1,57,380 bp and 1,58,744 bp which includes LSC, SSC, IRa, and IRb, while their GC content was 37.1% and 37% respectively. The variation in the length of genes e.g. ndhD, ndhI, rpl22, rpoC2, rps16, rps19, rps8, ycf1and ycf2 noted. Data help to document the genetic differences between usual (climber) with those of tree cucurbits.  相似文献   

15.
Liu  Fenxiang  Movahedi  Ali  Yang  Wenguo  Xu  Dezhi  Jiang  Chuanbei  Xie  Jigang  Zhang  Yu 《Molecular biology reports》2021,48(11):7113-7125
Background

An ornamental plant often seen in gardens and farmhouses, Musa basjoo Siebold can also be used as Chinese herbal medicine. Its pseudostem and leaves are diuretic; its root can be decocted together with ginger and licorice to cure gonorrhea and diabetes; the decoct soup of its pseudostem can help relieve heat, and the decoct soup of its dried flower can treat cerebral hemorrhage. There have not been many chloroplast genome studies on M. basjoo Siebold.

Methods and results

We characterized its complete chloroplast genome using Novaseq 6000 sequencing. This paper shows that the length of the chloroplast genome M. basjoo Siebold is 172,322 bp, with 36.45% GC content. M. basjoo Siebold includes a large single-copy region of 90,160 bp, a small single-copy region of 11,668 bp, and a pair of inverted repeats of 35,247 bp. Comparing the genomic structure and sequence data of closely related species, we have revealed the conserved gene order of the IR and LSC/SSC regions, which has provided a very inspiring discovery for future phylogenetic research.

Conclusions

Overall, this study has constructed an evolutionary tree of the genus Musa species with the complete chloroplast genome sequence for the first time. As can be seen, there is no obvious multi-branching in the genus, and M. basjoo Siebold and Musa itinerans are the closest relatives.

  相似文献   

16.
The nucleosome formation potential of introns, intergenic spacers and exons of human genes is shown here to negatively correlate with among-tissues breadth of gene expression. The nucleosome formation potential is also found to negatively correlate with the GC content of genomic sequences; the slope of regression line is steeper in exons compared with noncoding DNA (introns and intergenic spacers). The correlation with GC content is independent of sequence length; in turn, the nucleosome formation potential of introns and intergenic spacers positively (albeit weakly) correlates with sequence length independently of GC content. These findings help explain the functional significance of the isochores (regions differing in GC content) in the human genome as a result of optimization of genomic structure for epigenetic complexity and support the notion that noncoding DNA is important for orderly chromatin condensation and chromatin-mediated suppression of tissue-specific genes.  相似文献   

17.
Structural features of the wheat plastome were clarified by comparison of the complete sequence of wheat chloroplast DNA with those of rice and maize chloroplast genomes. The wheat plastome consists of a 134,545-bp circular molecule with 20,703-bp inverted repeats and the same gene content as the rice and maize plastomes. However, some structural divergence was found even in the coding regions of genes. These alterations are due to illegitimate recombination between two short direct repeats and/or replication slippage. Overall comparison of chloroplast DNAs among the three cereals indicated the presence of some hot-spot regions for length mutations. Whereas the region with clustered tRNA genes and that downstream of rbcL showed divergence in a species-specific manner, the deletion patterns of ORFs in the inverted-repeat regions and the borders between the inverted repeats and the small single-copy region support the notion that wheat and rice are related more closely to each other than to maize.  相似文献   

18.
虎杖(Reynoutria japonica Houtt.)为蓼科(Polygonaceae)蓼族(Polygoneae)虎杖属(Reynoutria Houtt.)植物,是一种传统的中草药,具有利湿退黄、清热解毒、散瘀止痛、止咳化痰的功效。本研究采取高通量测序技术获得5个虎杖品种的叶绿体全基因组序列,并与NCBI已公布的蓼族何首乌(Fallopia multiflora)和金线草(Antenoron filiforme)等植物的叶绿体全基因组序列进行了基因组学和系统发育分析。通过基因组学分析发现,5种虎杖的叶绿体基因组大小有163 376 bp和163 371 bp两种情况,并呈现出典型的环状四分体结构,85 784 bp的一条较长的单拷贝区(large single-copy region,LSC),18 616 bp的一条较短的单拷贝区(small single-copy region,SSC),还有两条长度一致的反向重复区,分别为IRa区和IRb区相间隔分布。通过注释得到161个基因,其中蛋白编码基因106个,rRNA编码基因10个,tRNA编码基因45个。总GC含量为36.7...  相似文献   

19.
This work reports the complete plastid (pt) DNA sequence of Seseli montanum L. of the Apiaceae family, determined using next-generation sequencing technology. The complete genome sequence has been deposited in GenBank with accession No. KM035851. The S. montanum plastome is 147,823 bp in length. The plastid genome has a typical structure for angiosperms and contains a large single-copy region (LSC) of 92,620 bp and a small single-copy region (SSC) of 17,481 bp separated by a pair of 18,861 bp inverted repeats (IRa and IRb). The composition, gene order, and AT-content in the S. montanum plastome are similar to that of a typical flowering plant pt DNA. One hundred fourteen unique genes have been identified, including 30 tRNA genes, four rRNA genes, and 80 protein genes. Of 18 intron-containing genes found, 16 genes have one intron, and two genes (ycf3, clpP) have two introns. Comparative analysis of Apiaceae plastomes reveals in the S. montanum plastome a LSC/IRb junction shift, so that the part of the ycf2 (4980 bp) gene is located in the LSC, but the other part of ycf2 (1301 bp) is within the inverted repeat. Thus, structural rearrangements in the plastid genome of S. montanum result in an enlargement of the LSC region by means of capture of a large part of ycf2, in contrast to eight Apiaceae plastomes where the complete ycf2 gene sequence is located in the inverted repeat.  相似文献   

20.
Interspecific and intergeneric relationships of Prunus s.l. are still unclear due to low levels of genetic variation among species, and resulting partially unresolved phylogenetic inferences. Here we sequenced and compared six complete plastomes from two subgenera of Prunus in order to choose molecular markers to increase the amount of genetic variation suitable for inference of Prunus phylogeny. The plastomes range between 157 817 and 158 995 bp in length, and we found different levels of inverted repeat (IR) contraction among the three sampled subgenera of Prunus s.l. Most regions in Prunus plastomes considered individually provide low phylogenetic resolution at the subgenus or species level compared to a tree constructed using all 78 coding regions combined. We compared levels of variation among 206 coding regions and noncoding (intergenic and intron) plastid regions and inferred phylogenies from each region considered individually. We then chose using two regions together for future studies of relationships in Prunus, ycf1 and trnT-L, that display high to moderate levels of variation among coding and intergenic regions, respectively, and that individually permit inference of resolved species-level trees in Prunus with moderate to strong branch support. Considered together, these two regions allow inference of the same topology of Prunus inferred using all coding plastid regions combined, with comparable levels of tree support to the full plastome set. These two loci should therefore be useful as a plastid phylogenetic marker set for further inference of relationships within Prunus s.l.  相似文献   

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