Inverted Repeat Research Articles

Cladopus yangjiangensis (Podostemaceae), a new species from Guangdong, South China, redefining the phylogenetic relationships within Cladopus

This paper introduces Cladopus yangjiangensis, a newly identified species that enriches our understanding of the diversity of the Podostemaceae in East Asia. Distinctive in its morphological traits, this species is characterized by the region’s longest flowering shoots and exhibits a high number of elongated leaves per cluster, along with relatively slender roots. Phylogenetic analyses using Maximum Likelihood and Bayesian Inference methods on plastome and matK sequences confirm C. yangjiangensis as a distinct species. It forms a clade with C. fukienensis, its closest relative, together branching off from C. austrosinensis. The plastome of C. yangjiangensis is 132,818 bp in length, comprising two inverted repeat regions of 20,881 bp, which are separated by large and small single-copy regions of 78,713 and 12,343 bp, respectively. Genetic analysis reveals the extensive loss of the ycf1 and ycf2 genes in the chloroplast genome, a trait common to the Podostemaceae, suggesting adaptations to environmental conditions or gene transfers to nuclear or mitochondrial genomes. This study improves the clarity of phylogenetic relationships in previous studies and underscores the importance of continued taxonomic and phylogenetic research.

The complete chloroplast genome sequence of Melothria scabra (Cucurbitaceae)

Melothria scabra has gradually become an economically important plant worldwide. The complete chloroplast genome of M. scabra has a length of 156,744 bp, contains a large single-copy (LSC) region (86,387 bp), a small single-copy (SSC) region (18,055 bp), and two inverted repeats (IRs) with the same length of 26,151 bp. In total, 126 genes were detected, including 83 protein-encoding genes, 35 transfer RNA (tRNA) genes, and eight ribosomal RNA (rRNA) genes. For phylogenetic analysis, M. scabra has a closer genetic relationship with Cucumis sativus and Citrullus lanatus. The complete chloroplast genome sequence of M. scabra would promote the germplasm exploration, phylogenetic relationships, and molecular biology researches in Melothria.

The complete chloroplast genome of Syzygium zeylanicum (Myrtaceae, Myrtales) and its phylogenetic analysis

The complete chloroplast genome of Syzygium zeylanicum (L.) DC. 1828 has been sequenced and analyzed for the first time. The S. zeylanicum chloroplast genome is 159,445 bp in length, comprised of a large single-copy region (88,034 bp), a small single-copy region (18,455 bp), and a pair of inverted repeat regions (26,478 bp each). The genome encoded 85 protein-coding genes, 37 tRNA genes, and eight rRNA genes. Phylogenetic analysis indicated that S. zeylanicum is closely related to S. acuminatissimum. This research provides essential genomic data for S. zeylanicum, offering valuable resources for future comparative genomics, phylogenetics, and conservation biology studies.

Characterization and Phylogenetic Analysis of the First Complete Chloroplast Genome of Shizhenia pinguicula (Orchidaceae: Orchideae).

Genomic analysis is crucial for better understanding the evolutionary history of species and for their conservation. Shizhenia pinguicula is a rare medicinal plant endemic to China. However, the complete chloroplast genome of this species has not been reported to date. Insufficient genomic research on S. pinguicula has hindered effective conservation efforts for this valuable plant. In this study, we sequenced and assembled the first complete chloroplast genome of S. pinguicula using Illumina sequencing technology. We conducted a comparative analysis of its chloroplast genome with related species and reconstructed phylogenetic relationships. The chloroplast genome of S. pinguicula exhibited a typical quadripartite structure with a length of 158,658 bp. A total of 123 genes, 118 simple sequence repeats, and 51 dispersed repetitive sequences were identified. The inverted repeat boundaries were significantly expanded, along with the pseudogenization and loss of multiple NDH genes. Codon usage bias is primarily influenced by natural selection and other factors, with the ycf3 gene under positive selection. Additionally, 10 hypervariable regions were detected for species identification and evolutionary studies. Phylogenetic analysis indicated that Ponerorchis gracilis and Hemipilia yajiangensis form a clade, with S. pinguicula as their sister species, located at the basal position of the Ponerorchis-Hemipilia alliance. The chloroplast genome structure and gene content of S. pinguicula exhibit certain degrees of variation compared to other species within the Orchidinae subtribe. This genome should be useful for further investigations into the biology of Shizhenia and the development of biodiversity conservation strategies.

Unveiling the intricate structural variability induced by repeat-mediated recombination in the complete mitochondrial genome of Cuscuta gronovii Willd

Cuscuta gronovii Willd., a member of the Convolvulaceae family, is noted for its potential medicinal and nutritional benefits. In this study, we utilized a combination of Illumina and Oxford Nanopore sequencing technologies to successfully assemble the complete circular mitochondrial genome (mitogenome) of C. gronovii. The mitogenome, spanning 304,467 base pairs, includes 54 genes: 33 protein-coding genes, three ribosomal RNA (rRNA) genes, and 18 transfer RNA (tRNA) genes. Beyond its primary circular structure, we discovered and validated several alternative genomic conformations, driven by five specific repeat sequences. Three inverted repeats were found to initiate rearrangements, resulting in the creation of seven distinct chromosomal structures, while two direct repeats split a larger molecule into two subgenomic entities. We also mapped 421 RNA editing sites across the protein-coding sequences, influencing 33 protein-coding genes with varying distribution, particularly noting high frequencies in the nad4 and ccmB genes. Sixteen of these RNA editing sites were experimentally validated through PCR amplification and Sanger sequencing, confirming their presence with 100 % accuracy. This research not only introduces the first mitochondrial genome of C. gronovii but also highlights its complex conformational variability induced by repeat-mediated recombination, providing a valuable genomic resource for further molecular breeding efforts and phylogenetic evolution within the genus Cuscuta.

Unified Assembly of Chloroplast Genomes: A Comparative Study of Grapes Representing Global Geographic Diversity

The genus Vitis, known for its economically important fruit—grape—is divided into three geographical groups, American, East Asian, and Eurasian, along with a hybrid group. However, previous studies on grape phylogeny using chloroplast genomes have been hindered by limited sample sizes and inconsistent methodologies, resulting in inaccuracies. In this study, we employed the GetOrganelle software with consistent parameters to assemble the chloroplast genomes of 21 grape cultivars, ensuring comprehensive representation across four distinct groups. A comparative analysis of the 21 grape cultivars revealed structural variation, showing chloroplast genome sizes ranging from 160,813 bp to 161,275 bp. In 21 Vitis cultivars, genome annotation revealed 134 to 136 genes, comprising 89 to 91 protein-coding genes (PCGs), 37 tRNAs, and 8 rRNAs. Our observations have pinpointed specific occurrences of contraction and expansion phenomena at the interfaces between inverted repeat (IR) regions and single-copy (SC) regions, particularly in the vicinity of the rpl2, ycf1, ndhF, and trnN genes. Meanwhile, a total of 193 to 198 SSRs were identified in chloroplast genomes. The diversification pattern of chloroplast genomes exhibited strong concordance with the phylogenetic relationships of the Euvitis subgenera. Phylogenetic analysis based on conserved chloroplast genome strongly clustered the grape varieties according to their geographical origins. In conclusion, these findings enhance our understanding of chloroplast genome variation in Vitis populations and have important implications for cultivar selection, breeding, and conservation efforts.

The chloroplast genome of Cephalanthera nanchuanica (Orchidaceae): comparative and phylogenetic analysis with other Neottieae species

BackgroundCephalanthera nanchuanica is a terrestrial orchid species and has been red listed as a second-grade protected plant due to its limited distributions in China. Initially classified within a monotypic genus Tangtsinia, this species was later reassigned to Cephalanthera based on morphological and molecular data. However, previous phylogenetic analyses of Cephalanthera using several segment sequences exhibited a low discriminatory power in delineating its relationships.ResultsIn this study, we characterized and comparatively analyzed the complete chloroplast (cp) genome of C. nanchuanica with those of six previously reported Cephalanthera species. Our findings revealed that the cp genome of C. nanchuanica had the typical quadripartite structure, with a size of 161,365 bp and a GC content of 37.27%. A total of 113 unique genes were annotated, among which nearly half of protein-encoding genes (RSCU > 1) showed a preference in codon usage. No structural rearrangements were observed among the cp genomes of Cephalanthera species, except for C. humilis, which displayed structural alterations due to gene loss, relocation, and inverted repeat (IR) expansion/contraction. The cp genomes of Cephalanthera species were highly conserved, with only a small number of SSRs detected, most of which preferred A/T bases. Comparative analysis of cp genomes indicated that IR and coding regions were less divergent than single copy and non-coding regions and eight mutational hotspots were identified. Phylogenetic analysis suggested that the tribe Neottieae was a monophyletic group, divided into five clades. Palmorchis was the earliest-diverging lineage, followed by Cephalanthera. Diplandrorchis was deeply nested within Neottia, forming a clade. Aphyllorchis and Limodorum formed another clade, sister to Epipactis. Within the Cephalanthera clade, C. nanchuanica was sister to C. falcata with a strong support.ConclusionsThis study demonstrated that the cp genome characters of C. nanchuanica are highly similar to those of other Cephalanthera species, except for the mycoheterotrophic species C. humilis. Although the cp genomes of Cephalanthera species (excluding C. humilis) exhibited conservation in genome structure and sequence, SSR repeats and mutational hotspots were identified, which could potentially serve as as molecular markers for distinguishing Cephalanthera species. The phylogenetic analysis based on the protein-coding genes provided high-resolution support for the infrageneric classification. Therefore, cp genome data will be instrumental in resolving the phylogeny of the genus Cephalanthera.

The complete mitochondrial DNA of the carnivorous sponge Lycopodina hypogea is putatively complemented by microDNAs.

Carnivorous sponges (Porifera, Demospongiae, Cladorhizidae), contrary to the usual filter-feeding mechanism of sponges, are specialized in catching larger prey through adhesive surfaces or hook-like spicules. The mitochondrial DNA of sponges overall present several divergences from other metazoans, and while presenting unique features among major transitions, such as in calcarean and glass sponges, poriferan mitogenomes are relatively stable within their groups. Here, we report and discuss the mitogenome of Lycopodina hypogea (Vacelet & Boury-Esnault, 1996), which greatly vary from its subordinal counterparts in both structure and gene order. This mitogenome is seemingly multipartite into three chromosomes, two of them as microDNAs. The main chromosome, chrM1, is unusually large, 31,099 bp in length, has a unique gene order within Poecilosclerida, and presents two rRNA, 13 protein and 19 tRNA coding genes. Intergenic regions comprise approximately 40% of chrM1, bearing several terminal direct and inverted repeats (TDRr and TIRs) but holding no vestiges of former mitochondrial sequences, pseudogenes, or transposable elements. The nd4l and trnI(gau) genes are likely located in microDNAs thus comprising putative mitochondrial chromosomes chrM2, 291 bp, and chrM3, 140 bp, respectively. It is unclear which processes are responsible for the remarkable features of the of L. hypogea mitogenome, including a generalized gene rearrangement, long IGRs, and putative extrachromosomal genes in microDNAs.

Stabilization of a single-stranded DNA of adeno-associated virus by inverted terminal repeats

Parvoviruses have evolved to possess a linear single-stranded DNA (ssDNA) genome ranging from 4 to 6.3 kb. Adeno-associated virus (AAV), a member of the Parvoviridae family, contains approximately 5 kb of linear ssDNA within its capsid. This ssDNA features two 145-base inverted terminal repeats (ITRs) positioned at each end. ITRs have a T-shaped hairpin secondary structure, which plays a crucial role in viral replication. To investigate the impact of ITRs on ssDNA stability, we conducted a DNA denaturation-reannealing assay in 10 mM magnesium acetate, 50 mM potassium acetate, and 20 mM Tris-acetate buffer at pH7.9. Conventional double-stranded DNA (dsDNA) fragments retain a reannealing capability of over 50% for sizes under 8.8 kb, gradually losing this capability as sizes increase; however, dsDNA fragments in rAAV ranging from 0.7 to 6.3 kb did not exhibit a reannealing profile. This suggests that the presence of ITRs at both ends hinders annealing between the complementary strands. These results indicate that ITR structures preferentially induce an ssDNA conformation less than 6.3 kb in size, and that the stability of AAV ssDNA contributes to the viral life cycle, including processes such as infection, replication, and packaging. Considering the size of parvovirus genomes, it appears that their genomes require reversible flexibility in complementary DNA strands; simultaneously, this adaptability needs to be regulated by specific palindromic ITRs at both ends.

Kazakhstan tulips: comparative analysis of complete chloroplast genomes of four local and endangered species of the genus Tulipa L.

Species of Tulipa are important ornamental plants used for horticultural purposes in various countries, across Asia, Europe, and North Africa. The present study is the first report on typical features of the complete chloroplast genome sequence of four local and endangered species including T. alberti, T. kaufmanniana, T. greigii, and T. dubia from Kazakhstan using Illumina sequencing technology. The comparative analyses revealed that the complete genomes of four species were highly conserved in terms of total genome size (152. 006 bp - 152. 382 bp), including a pair of inverted repeat regions (26. 330 bp - 26. 371 bp), separated by a large single copy region (82.169 bp - 82,378 bp) and a small copy region (17.172 bp -17.260 bp). Total GC content (36.58-36.62 %), gene number (131), and intron length (540 bp - 2620 bp) of 28 genes. The complete genomes of four species showed nucleotide diversity (π =0,003257). The total number of SSR loci was 159 in T. alberti, 158 in T. kaufmanniana, 174 in T. greigii, and 163 in T. dubia. The result indicated that ten CDS genes, namely rpoC2, cemA, rbcL, rpl36, psbH, rps3, rpl22, ndhF, ycf1, and matK, with effective polymorphic simple sequence repeats (SSRs), high sequence variability (SV) ranging from 2.581 to 6.102, and high nucleotide diversity (Pi) of these loci ranging from 0,004 to 0,010. For all intergenic regions longer than 150 bp, twenty one most variable regions were found with high sequence variability (SV) ranging from 4,848 to 11,862 and high nucleotide diversity (Pi) ranging from 0,01599 to 0,01839. Relative synonymous codon usage (RSCU) analysis was used to identify overrepresented and underrepresented codons for each amino acid. Based on the phylogenic analysis, the sequences clustered into four major groups, reflecting distinct evolutionary lineages corresponding to the subgenera Eriostemons, Tulipa, and Orithyia. Notably, T. greigii was distinctively grouped with species from Orithyia and Eriostemons rather than with other Tulipa species, suggesting a unique evolutionary history potentially shaped by geographical isolation or specific ecological pressures. The complete chloroplast genome of the four Tulipa species provides fundamental information for future research studies, even for designing the high number of available molecular markers.

The chloroplast genome sequence and phylogenetic analysis of Rubia alata Wall and Rubia ovatifolia Z. Ying Zhang. (Rubiaceae).

Rubia alata Wall (R. alata) and Rubia ovatifolia Z. Ying Zhang (R. ovatifolia) are unique medicinal plants native to China. Sequencing their chloroplast genomes is important for understanding species differentiation and establishing phylogenetic relationships. The chloroplast genomes of R. alata and R. ovatifolia were sequenced using the Illumina HiSeq platform. The chloroplast genome of R. alata is 154,973 base pairs (bp) in length, containing a large single-copy region (LSC) of 84,801bp, a small single-copy region (SSC) of 17,138bp, and a pair of inverted repeats (IRs) of the same length. The length of the chloroplast genome, LSC, SSC, and IR regions of R. ovatifolia is 26,517bp, 84,716bp, 17,116bp and 26,517bp, respectively. Codon usag e analysis revealed that R. alata had the highest frequency of Aspartic acid (Asp) (1650 occurrences) in protein-coding sequences (CDS), while R. ovatifolia showed the highest frequency of Tyrosine (Try) (1479 occurrences). Comparative analysis of chloroplast genomes across seven species from the genus Rubia identified the most divergent coding regions, including rps16, psbI-trns-CGA, and petN, while plastid rRNAs were the most conserved. Phylogenetic analysis showed R. alata clustering with R. cordifolia (66.3% support), and R. ovatifolia clustering with Rubia podantha (100% support). These findings enhance our understanding of the chloroplast genome structure in Rubia species and provide molecular information for the future development and utilization of R. alata and R. ovatifolia resources.

Mitochondrial Genome Analysis of Babesia ovis (Apicomplexa: Babesiidae) Endemic in Sheep in Türkiye.

This study presents the first comprehensive analysis of the mitochondrial genome of Babesia ovis, a significant pathogen in ovine babesiosis in Türkiye. The B. ovis mitochondrial genome is a linear monomeric molecule of 6015 bp with an A + T content of 70.5%, featuring terminal inverted repeats (TIRs) at both ends. It encodes three essential proteins (Cox1, Cox3, and Cob) and six fragments of large subunit rRNA genes. Comparative analysis revealed high sequence identity with Babesia sp. Xinjiang (87.5%) and Babesia sp. Dunhuang (87.5%), suggesting a close evolutionary relationship. The study highlights the conservation of mitochondrial gene content across Babesia and Theileria species, emphasizing their utility in phylogenetic studies. The findings also suggest that TIR variability plays a role in mitochondrial genome size differences, influencing species-specific adaptations. This research provides valuable insights into the evolution and functional adaptations of B. ovis and underscores the potential of mitochondrial genomic data in enhancing diagnostic and therapeutic strategies for babesiosis. Further exploration of mitochondrial genomes in Babesia species is essential for understanding their biology and developing effective control measures.

De Novo Sequencing of Drymaria villosa and Comparative Analysis of Plastome in Caryophyllaceae Across 23 Species.

Plant plastome are well studied due to their essential roles in photosynthesis and plant development. Comparative studies among plastome of closely related genera or families are limited, hindering our understanding of evolutionary changes and adaptation. This study presents a comparative analysis of 23 Caryophyllaceae plastome revealing a dynamic interplay of conserved and variable features. The genome size exhibited a moderate coefficient of variation (CV) of 2.58%. The large single-copy (LSC) and small single-copy (SSC) regions were highly conserved, with CVs of 2.55% and 2.00%, respectively. In contrast, the inverted repeat (IR) regions displayed greater variability, with a CV of 4.23%, indicating dynamic evolutionary processes. Exon counts varied significantly (CV 17.20%), while intron counts showed some variability (CV 7.79%), reflecting diverse gene structures. Coding sequences had moderate variability (CV 3.67%), while non-coding sequences varied more (CV 5.05%). tRNA counts were slightly variable (CV 2.67%), and GC content was notably consistent (CV 0.40%). This study includes the newly sequenced plastome of Drymaria villosa (GenBank accession OR790517), confirming its placement within Caryophyllaceae with significant diversification through phylogenetic analysis. Correlations (> 0.6) among plastome components and genome size reflect their tight evolutionary linkage, enhancing our understanding of plastome evolution in Caryophyllaceae and aiding future investigations into the ecological and medicinal potential of D. villosa and related species.

Deciphering the complex organelle genomes of two Rhododendron species and insights into adaptive evolution patterns in high-altitude

BackgroundThe genomes within organelles are crucial for physiological functions such as respiration and photosynthesis and may also contribute to environmental adaptation. However, the limited availability of genetic resources, particularly mitochondrial genomes, poses significant challenges for in-depth investigations.ResultsHere, we explored various assembly methodologies and successfully reconstructed the complex organelle genomes of two Rhododendron species: Rhododendron nivale subsp. boreale and Rhododendron vialii. The mitogenomes of these species exhibit various conformations, as evidenced by long-reads mapping. Notably, only the mitogenome of R. vialii can be depicted as a singular circular molecule. The plastomes of both species conform to the typical quadripartite structure but exhibit elongated inverted repeat (IR) regions. Compared to the high similarity between plastomes, the mitogenomes display more obvious differences in structure, repeat sequences, and codon usage. Based on the analysis of 58 organelle genomes from angiosperms inhabiting various altitudes, we inferred the genetic adaptations associated with high-altitude environments. Phylogenetic analysis revealed partial inconsistencies between plastome- and mitogenome-derived phylogenies. Additionally, evolutionary lineage was determined to exert a greater influence on codon usage than altitude. Importantly, genes such as atp4, atp9, mttB, and clpP exhibited signs of positive selection in several high-altitude species, suggesting a potential link to alpine adaptation.ConclusionsWe tested the effectiveness of different organelle assembly methods for dealing with complex genomes, while also providing and validating high-quality organelle genomes of two Rhododendron species. Additionally, we hypothesized potential strategies for high-altitude adaptation of organelles. These findings offer a reference for the assembly of complex organelle genomes, while also providing new insights and valuable resources for understanding their adaptive evolution patterns.

Discovery of the first Tn630 member and the closest homolog of IS630 from viruses

IS630/Tc1/mariner (ITm) represents the most widely distributed superfamily of DNA transposons in nature. Currently, bioinformatics research on ITm members primarily involves collecting data of existing and emerging members and organizing them into new groups or families. In the present study, our survey revealed that Tc1 and IS630 members have a broad host range, spanning across all six biological kingdoms (bacteria, fungi, plantae, animalia, archaea and protista) and viruses. The primary discoveries include the first Tn630 member—Tn630-NC1 and the closest homolog of IS630 from viruses—Tc1-C#1. By incorporating our discoveries into existing knowledge, we proposed a model to elucidate the formation of composite transposons. Organization of Tc1 and IS630 members into groups across biological kingdoms facilitates data collection for future research, particularly on their horizontal transfer between different kingdoms. The formation of composite transposons may result from asymmetric of terminal inverted repeats. IS630 should be merged with Tc1 into a single family IS630/Tc1. Furthermore, IS630 and its homologs constitute a valuable resource for studying horizontal gene transfer between gut bacteria and phages, opening up new avenues for research in this field.

ALTERED MERISTEM PROGRAM1 impairs RNA silencing by repressing the biogenesis of a subset of inverted repeat-derived siRNAs.

RNA silencing negatively regulates gene expression at the transcriptional and post-transcriptional levels through DNA methylation, histone modification, mRNA cleavage, and translational inhibition. Small interfering RNAs (siRNAs) of 21 to 24 nucleotides are processed from double-stranded RNAs by Dicer-like enzymes and play essential roles in RNA silencing in plants. Here, we demonstrated that ALTERED MERISTEM PROGRAM1 (AMP1) and its putative paralog LIKE AMP1 (LAMP1) impair RNA silencing by repressing the biogenesis of a subset of inverted repeat (IR)-derived siRNAs in Arabidopsis (Arabidopsis thaliana). AMP1 and LAMP1 inhibit Pol II-dependent IR gene transcription by suppressing ARGONAUTE 1 (AGO1) protein levels. Genetic analysis indicates that AMP1 acts upstream of RNA polymerase IV subunit 1 (NRPD1), RNA-dependent RNA polymerase 2 (RDR2), and Dicer-Like 4 (DCL4), which are required for IR-induced RNA silencing. We also show that AMP1 and LAMP1 inhibit siRNA-mediated silencing in a different mechanism from AGO4 and DCL3. Together, these results reveal two previously unknown players in siRNA biogenesis from IRs - AGO1, which promotes IR transcription, and AMP1, which inhibits IR transcription indirectly through the repression of AGO1 expression.

The complete plastome of a newly described species, Iris cangshanensis

Iris cangshanensis X. F Jiang, Y. Yang, J. F Liu & Y. P Xie, 2024, is a newly described perennial herb with a small population size. This study utilized Illumina sequencing technology to construct the complete chloroplast genome of Iris cangshanensis. The chloroplast genome is 154,008 base pairs (bp) in size with 37.32% overall GC content, consisting of an 83,559 bp (35.35%) large single-copy region (LSC), a 17,937 bp (30.56%) small single-copy region (SSC), and a pair of 26,256 bp (42.78%) inverted repeat (IR) sequences. The chloroplast genome has 130 genes, including 84 protein-coding genes, 38 tRNA genes, and eight rRNA genes. A maximum-likelihood (ML) phylogenetic analysis based on the plastomes of 15 Iridaceae species revealed that Iris cangshanensis is closely related to the other 12 species within the Iris genus. Owing to the limited chloroplast genome sampling of the genus Iris in the present study, determining the position of Iris cangshanensis in this genus is difficult. Overall, the chloroplast genome reported in this study will be useful for further taxonomic and evolutionary studies of Iris. This study constructs the complete chloroplast genome of Iris cangshanensis. The chloroplast genome is 154,008 base pairs (bp) in size with 37.32% overall GC content, consisting of an 83,559 bp (35.35%) large single-copy region (LSC), a 17,937 bp (30.56%) small single-copy region (SSC), and a pair of 26,256 bp (42.78%) inverted repeat (IR) sequences. The chloroplast genome has 130 genes, including 84 protein-coding genes, 38 tRNA genes, and eight rRNA genes. A maximum-likelihood (ML) phylogenetic analysis based on 15 Iridaceae species revealed that Iris cangshanensis is closely related to the species within the Iris genus.

Characterization and phylogenetic analysis of the complete chloroplast genome sequence of Phalaenopsis deliciosa (Rchb. f. 1854)

Phalaenopsis deliciosa (Rchb. f.), an ornamental orchid known for vibrant flowers, has a 148,090 bp chloroplast genome with 36.78% GC content. It includes an 85,241 bp large single-copy (LSC) region, an 11,649 bp small single-copy (SSC) region, and two 13,800 bp inverted repeats (IRs), encoding 122 genes (76 protein-coding, 38 tRNA, and 8 rRNA). This genome data refines the Phalaenopsis gene database and supports research on phylogeny and molecular breeding.

The complete chloroplast genome sequence of Michelia xinningia (Magnoliaceae)

Michelia xinningia is an evergreen garden plant with attractive and fragrant flowers. Michelia exhibits both interspecific and intraspecific phenotypic variability. However, the genetic diversity of M. xinningia has not been thoroughly investigated. This study analyzed the first chloroplast genome of M. xinningia, which was 160,082 bp, including a large single-copy (LSC) region of 88,112 bp, a small single-copy (SSC) region of 18,798 bp, and a pair of inverted repeat (IRs) regions of 26,586 bp. It contained 133 genes, including 87 protein-coding genes, 38 transfer RNA genes, and eight ribosomal RNA genes. Phylogenetic analysis showed that M. xinningia formed a close relationship with M. foveolata. This study will provide an opportunity to investigate genetic variation and could be useful for both species identification and conservation.

Complete chloroplast genome and phylogenetic analysis of Lonicera microphylla Willd. ex Roem. & Schult. 1819 Caprifoliaceae

Lonicera microphylla Willd. ex Roem. & Schult. 1819 is a medicinal plant species, especially for treating chronic fever and dysentery. This study aimed to characterize the chloroplast genome of L. microphylla and reconstruct the phylogenetic relationships among Lonicera Linn. 1753. The circular complete chloroplast genome is 154,945 bp in length, with two inverted repeat regions (IRs; 23,841 bp), separated by a small single-copy region (SSC; 18,789 bp) and a large single-copy region (LSC; 88,474 bp). The overall GC content of L. microphylla plastome was 38.36%. The chloroplast genome encoded a total of 131 genes, including 84 protein-coding genes, 39 tRNA genes, and eight rRNA genes. Phylogenetic analysis reveals that L. microphylla was more closely related to Lonicera tangutica Maxim. 1878. Our result can provide reference for the phylogenetic relationship, resource development, and utilization of Lonicera.