Molecular analysis of a 21.1-kb fragment of wheat chloroplast DNA bearing RNA polymerase subunit (rpo) genes

Genome ◽  
1999 ◽  
Vol 42 (6) ◽  
pp. 1042-1049
Author(s):  
Y Ohnishi ◽  
H Tajiri ◽  
Y Matsuoka ◽  
K Tsunewaki

The entire nucleotide sequence of a 21.1-kb fragment of wheat chloroplast (ct) DNA was determined. This fragment carries 18 intact genes and parts of two additional genes, including the three RNA polymerase genes rpoB, rpoC1, and rpoC2. The gene arrangement of this region is conserved in wheat, rice, and maize, but not in non-grass species. Comparison of these 20 genes in wheat, rice, and maize showed that tRNA genes evolved more slowly than protein-coding genes in the chloroplast genome. Intergenic regions evolved much faster than both types of genes. Although the 19 genes of wheat, except for orf42, showed high identity to those of other plants, there were three novel structural features in the wheat rpoC2 gene; a deletion of 81 bp in the middle region, a variable insertion (408 bp), and a nonsense mutation in the 3' terminal region, resulting in truncation of a sequence of ca. 10 amino acids. An intermolecular recombination between the stretches of CTTAT and CTTTT was suggested as the mechanism of the 81-bp deletion in the wheat rpoC2 gene. Evolutionary distance between the chloroplast genomes of wheat and maize was larger than those between wheat and rice and between rice and maize.Key words: common wheat, chloroplast genes, evolutionary divergence, phylogeny.

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Bobby Lim-Ho Kong ◽  
Hyun-Seung Park ◽  
Tai-Wai David Lau ◽  
Zhixiu Lin ◽  
Tae-Jin Yang ◽  
...  

AbstractIlex is a monogeneric plant group (containing approximately 600 species) in the Aquifoliaceae family and one of the most commonly used medicinal herbs. However, its taxonomy and phylogenetic relationships at the species level are debatable. Herein, we obtained the complete chloroplast genomes of all 19 Ilex types that are native to Hong Kong. The genomes are conserved in structure, gene content and arrangement. The chloroplast genomes range in size from 157,119 bp in Ilex graciliflora to 158,020 bp in Ilex kwangtungensis. All these genomes contain 125 genes, of which 88 are protein-coding and 37 are tRNA genes. Four highly varied sequences (rps16-trnQ, rpl32-trnL, ndhD-psaC and ycf1) were found. The number of repeats in the Ilex genomes is mostly conserved, but the number of repeating motifs varies. The phylogenetic relationship among the 19 Ilex genomes, together with eight other available genomes in other studies, was investigated. Most of the species could be correctly assigned to the section or even series level, consistent with previous taxonomy, except Ilex rotunda var. microcarpa, Ilex asprella var. tapuensis and Ilex chapaensis. These species were reclassified; I. rotunda was placed in the section Micrococca, while the other two were grouped with the section Pseudoaquifolium. These studies provide a better understanding of Ilex phylogeny and refine its classification.


PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e8450 ◽  
Author(s):  
Sunan Huang ◽  
Xuejun Ge ◽  
Asunción Cano ◽  
Betty Gaby Millán Salazar ◽  
Yunfei Deng

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.


Molecules ◽  
2018 ◽  
Vol 23 (9) ◽  
pp. 2137 ◽  
Author(s):  
Xiang-Xiao Meng ◽  
Yan-Fang Xian ◽  
Li Xiang ◽  
Dong Zhang ◽  
Yu-Hua Shi ◽  
...  

The genus Sanguisorba, which contains about 30 species around the world and seven species in China, is the source of the medicinal plant Sanguisorba officinalis, which is commonly used as a hemostatic agent as well as to treat burns and scalds. Here we report the complete chloroplast (cp) genome sequences of four Sanguisorba species (S. officinalis, S. filiformis, S. stipulata, and S. tenuifolia var. alba). These four Sanguisorba cp genomes exhibit typical quadripartite and circular structures, and are 154,282 to 155,479 bp in length, consisting of large single-copy regions (LSC; 84,405–85,557 bp), small single-copy regions (SSC; 18,550–18,768 bp), and a pair of inverted repeats (IRs; 25,576–25,615 bp). The average GC content was ~37.24%. The four Sanguisorba cp genomes harbored 112 different genes arranged in the same order; these identical sections include 78 protein-coding genes, 30 tRNA genes, and four rRNA genes, if duplicated genes in IR regions are counted only once. A total of 39–53 long repeats and 79–91 simple sequence repeats (SSRs) were identified in the four Sanguisorba cp genomes, which provides opportunities for future studies of the population genetics of Sanguisorba medicinal plants. A phylogenetic analysis using the maximum parsimony (MP) method strongly supports a close relationship between S. officinalis and S. tenuifolia var. alba, followed by S. stipulata, and finally S. filiformis. The availability of these cp genomes provides valuable genetic information for future studies of Sanguisorba identification and provides insights into the evolution of the genus Sanguisorba.


Plants ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 456 ◽  
Author(s):  
Cornelius M. Kyalo ◽  
Zhi-Zhong Li ◽  
Elijah M. Mkala ◽  
Itambo Malombe ◽  
Guang-Wan Hu ◽  
...  

Streptocarpus ionanthus (Gesneriaceae) comprise nine herbaceous subspecies, endemic to Kenya and Tanzania. The evolution of Str. ionanthus is perceived as complex due to morphological heterogeneity and unresolved phylogenetic relationships. Our study seeks to understand the molecular variation within Str. ionanthus using a phylogenomic approach. We sequence the chloroplast genomes of five subspecies of Str. ionanthus, compare their structural features and identify divergent regions. The five genomes are identical, with a conserved structure, a narrow size range (170 base pairs (bp)) and 115 unique genes (80 protein-coding, 31 tRNAs and 4 rRNAs). Genome alignment exhibits high synteny while the number of Simple Sequence Repeats (SSRs) are observed to be low (varying from 37 to 41), indicating high similarity. We identify ten divergent regions, including five variable regions (psbM, rps3, atpF-atpH, psbC-psbZ and psaA-ycf3) and five genes with a high number of polymorphic sites (rps16, rpoC2, rpoB, ycf1 and ndhA) which could be investigated further for phylogenetic utility in Str. ionanthus. Phylogenomic analyses here exhibit low polymorphism within Str. ionanthus and poor phylogenetic separation, which might be attributed to recent divergence. The complete chloroplast genome sequence data concerning the five subspecies provides genomic resources which can be expanded for future elucidation of Str. ionanthus phylogenetic relationships.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Wenbin Xu ◽  
Boshun Xia ◽  
Xinwei Li

AbstractThe six pinnate-leaved species are a very particular group in the genus Primula. In the present paper, we sequenced, assembled and annotated the chloroplast genomes of five of them (P. cicutarrifolia, P. hubeiensis, P. jiugongshanensis, P. merrilliana, P. ranunculoides). The five chloroplast genomes ranged from ~ 150 to 152 kb, containing 113 genes (four ribosomal RNA genes, 29 tRNA genes and 80 protein-coding genes). The six pinnate-leaved species exhibited synteny of gene order and possessed similar IR boundary regions in chloroplast genomes. The gene accD was pseudogenized in P. filchnerae. In the chloroplast genomes of the six pinnate-leaved Primula species, SSRs, repeating sequences and divergence hotspots were identified; ycf1 and trnH-psbA were the most variable markers among CDSs and noncoding sequences, respectively. Phylogenetic analyses showed that the six Primula species were separated into two distant clades: one was formed by P. filchnerae and P. sinensis and the other clade was consisting of two subclades, one formed by P. hubeiensis and P. ranunculoides, the other by P. merrilliana, P. cicutarrifolia and P. jiugongshanensis. P. hubeiensis was closely related with P. ranunculoides and therefore it should be placed into Sect. Ranunculoides. P. cicutarrifolia did not group first with P. ranunculoides but with P. merrilliana, although the former two were once united in one species, our results supported the separation of P. ranunculoides from P. cicutarrifolia as one distinct species.


Author(s):  
Wojciech Pląder ◽  
Yasushi Yukawa ◽  
Masahiro Sugiura ◽  
Stefan Malepszy

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.


2020 ◽  
Author(s):  
Aziz Ebrahimi ◽  
Jennifer D. Antonides ◽  
Cornelia C. Pinchot ◽  
James M. Slavicek ◽  
Charles E. Flower ◽  
...  

ABSTRACTAmerican elm, Ulmus americana L., was cultivated widely in USA and Canada as a landscape tree, but the genome of this important species is poorly characterized. For the first time, we describe the sequencing and assembly of the chloroplast genomes of two American elm genotypes (RV16 and Am57845). The complete chloroplast genome of U. americana ranged from 158,935-158,993 bp. The genome contains 127 genes, including 85 protein-coding genes, 34 tRNA genes and 8 rRNA genes. Between the two American elm chloroplasts we sequenced, we identified 240 sequence variants (SNPs and indels). To evaluate the phylogeny of American elm, we compared the chloroplast genomes of two American elms along with seven Asian elm species and twelve other chloroplast genomes available through the NCBI database. As expected, Ulmus was closely related to Morus and Cannabis, as all three genera are assigned to the Urticales. Comparison of American elm with Asian elms revealed that trnH was absent from the chloroplast of American elm but not most Asian elms; conversely, petB, petD, psbL, trnK, and rps16 are present in the American elm but absent from all Asian elms. The complete chloroplast genome of U. americana will provide useful genetic resources for characterizing the genetic diversity of U. americana and potentially help to conserve natural populations of American elm.


2019 ◽  
Author(s):  
Monique Turmel ◽  
Adriana Lopes dos Santos ◽  
Christian Otis ◽  
Roxanne Sergerie ◽  
Claude Lemieux

AbstractThe tiny green algae belonging to the Chloropicophyceae play a key role in marine phytoplankton communities; this newly erected class of prasinophytes comprises two genera (Chloropicon and Chloroparvula) containing each several species. We sequenced the plastomes and mitogenomes of eight Chloropicon and five Chloroparvula species to better delineate the phylogenetic affinities of these taxa and to infer the suite of changes that their organelle genomes sustained during evolution. The relationships resolved in organelle-based phylogenomic trees were essentially congruent with previously reported rRNA trees, and similar evolutionary trends but distinct dynamics were identified for the plastome and mitogenome. Although the plastome sustained considerable changes in gene content and order at the time the two genera split, subsequently it remained stable and maintained a very small size. The mitogenome, however, was remodeled more gradually and showed more fluctuation in size, mainly as a result of expansions/contractions of intergenic regions. Remarkably, the plastome and mitogenome lost a common set of three tRNA genes, with the trnI(cau) and trnL(uaa) losses being accompanied with important variations in codon usage. Unexpectedly, despite the disappearance of trnI(cau) from the plastome in the Chloroparvula lineage, AUA codons (the codons recognized by this gene product) were detected in certain plastid genes. By comparing the sequences of plastid protein-coding genes from chloropicophycean and phylogenetically diverse chlorophyte algae with those of the corresponding predicted proteins, we discovered that the AUA codon was reassigned from isoleucine to methionine in Chloroparvula. This noncanonical genetic code has not previously been uncovered in plastids.


PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e8762
Author(s):  
Yue Shen ◽  
Yu-Zhou Du

Of the roughly 400 species of Perlidae in the world, most species are widely distributed in the northern hemisphere, but a few can be found in South Africa and South America. There are only five species in the genus Flavoperla of the family Perlidae in China. To gain a better understanding of the architecture and evolution of mitochondrial genome in Flavoperla, the entire mitochondrial genome (mitogenome) of a Chinese Flavoperla biocellata Chu, 1929 from family Perlidae (Insecta: Plecoptera) was sequenced. The 15,805-bp long mitochondrial genome of F. biocellata contained 37 genes, including 13 protein-coding genes (PCGs), 22 transfer RNA genes (tRNAs), two ribosomal RNA genes (rRNAs) and a putative control region (CR). The gene arrangement of F. biocellata was identical with that of other stoneflies and with the fly Drosophila yakuba. Most PCGs of F. biocellata used the standard ATN start codons and complete TAN termination codons. Twenty-one of the 22 tRNA genes exhibited cloverleaf secondary structures, but the dihydrouridine (DHU) arm of trnSer (AGN) was completely reduced. Phylogenetic analyses with both Bayesian inference (BI) and maximum likelihood methods (ML) generated similar topology, both supporting the monophyly of all stonefly families and the infraorder Systellognatha. The phylogenetic analysis based on mitochondrial genomic data from 30 stonefly species recovered a well-supported tree resolving higher-level relationships within Plecoptera. The northern hemisphere suborder Arctoperlaria divided into two groups, Euholognatha and Systellognatha. The southern hemisphere suborder Antarctoperlaria formed two clades: Eustheniidae+Diamphipnoidae and Austroperlidae+ Gripopterygidae; consistent with relationships proposed based on morphology. The final relationships within Plecoptera were recovered as (((Perlidae+(Perlodidae+Chloroperlidae))+(Pteronarcyidae+(Peltoperlidae+Styloperlidae))) +(Taeniopterygidae+(Capniidae+(Nemouridae+Notonemouridae))))+ (Gripopterygoidae+Eusthenioidae).


2021 ◽  
Author(s):  
Yingfeng Niu ◽  
Chengwen Gao ◽  
Jin Liu

Abstract BackgroundAmong the Mangifera species, mango (Mangifera indica) is an important commercial fruit crop. However, very few studies have been conducted on the Mangifera mitochondrial genome. This study reports and compares the newly sequenced mitochondrial genomes of three Mangifera species. Results Mangifera mitochondrial genomes showed partial similarities in the overall size, genomic structure, and gene content. Specifically, the genomes are circular and contain about 63-69 predicted functional genes, including five ribosomal RNA (rRNA) genes and 24-27 transfer RNA (tRNA) genes. The GC contents of the Mangifera mitochondrial genomes are similar, ranging from 44.42–44.66%. Leucine (Leu) and serine (Ser) are the most frequently used, while tryptophan (Trp) and cysteine (Cys) are the least used amino acids among the protein-coding genes in Mangifera mitochondrial genomes. We also identified 7-10 large chloroplast genomic fragments in the mitochondrial genome, ranging from 1407-6142 bp. Additionally, four intact mitochondrial tRNAs genes (tRNA-Cys, tRNA-Trp, tRNA-Pro, and tRNA-Met) and intergenic spacer regions were identified. Phylogenetic analysis based on the common protein-coding genes of most branches provided a high support value. ConclusionsWe sequenced and compared the mitochondrial genomes of three Mangifera species. The results showed that the gene content of Mangifera mitochondrial genomes is similar across various species. Gene transferred from the chloroplast genome to the mitochondrial genome were identified. This study provides valuable information for evolutionary and molecular studies of Mangifera and a basis for further studies on genomic breeding of mango.


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