Search Results (69)

Orbea is a morphologically diverse lineage within the subtribe Stapeliinae, yet plastome evolution in Arabian taxa remains insufficiently characterized. This study reports the first complete chloroplast genomes of Orbea sprengeri subsp. commutata and O. wissmannii var. eremastrum and investigates plastome structure, sequence variability, and phylogenetic relationships across tribe Ceropegieae. Chloroplast genomes were assembled, annotated, and compared with 13 published plastomes representing major Ceropegieae lineages. Both Arabian plastomes displayed the typical quadripartite structure and identical gene content of 114 unique genes, including 80 protein-coding genes, 30 transfer RNA genes, and four ribosomal RNA genes. However, O. wissmannii var. eremastrum exhibited pronounced structural divergence, possessing the largest plastome recorded for the tribe (170,054 bp), an 8.9 kb expansion of the inverted repeat regions, and an 8.4 kb inversion spanning the ndhG–ndhF region. Comparative analyses revealed conserved gene order across Ceropegieae but identified six highly variable loci (accD, clpP, ndhF, ycf1, psbM–trnD, and rpl32–trnL) as potential DNA barcodes. Selection pressure analyses indicated strong purifying selection across most genes, with localized adaptive signals in accD, ndhE, ycf1, and ycf2. Phylogenomic reconstruction consistently resolved the two Arabian Orbea taxa as a distinct clade separate from the African O. variegata. This study fills a gap in Ceropegieae plastid genomics and underscores the importance of sequencing additional Orbea species to capture the full extent of genomic variation within this diverse genus. Full article

The chloroplast (cp) genome of Panicum bisulcatum (Thumb.), a significant agricultural weed, was sequenced and characterized to elucidate its genomic architecture, evolutionary dynamics, and phylogenetic relationships. The complete cp genome was assembled as a circular DNA molecule of 138,489 bp, exhibiting a typical quadripartite structure comprising a large single-copy (LSC, 82,260 bp), a small single-copy (SSC, 12,569 bp), and a pair of inverted repeats (IR, 21,830 bp each) regions. It encodes 135 genes, including 89 protein-coding genes, 49 tRNAs, and 8 rRNAs. Functional annotation revealed that most genes are involved in photosynthesis and genetic system. A total of 51 simple sequence repeats (SSRs) and 62 long repeats (LRs) were identified, providing potential molecular markers. Comparative analysis of IR boundaries highlighted both conserved features and species-specific expansion/contraction events among Panicum species. Phylogenomic analysis robustly placed P. bisulcatum within the genus Panicum, showing a closest relationship with P. incomtum and confirming the monophyly of the genus. Furthermore, single nucleotide polymorphism (SNP) analysis with its closest relative, P. incomtum, revealed 4659 SNPs, with a dominance of synonymous substitutions, indicating the action of purifying selection. This study provides the first comprehensive cp genomic resource for P. bisulcatum, which will facilitate future studies in species identification, phylogenetic reconstruction, population genetics, and the development of sustainable management strategies for this weed. Full article

The evolution of robust DNA repair mechanisms was a prerequisite for the conquest of land by plants, a transition that exposed them to harsh new environmental stressors. The poly (ADP-ribose) polymerase (PARP) family is central to this adaptation, as it orchestrates DNA repair and stress signaling pathways essential for coping with the elevated UV radiation and desiccation of terrestrial environments. Yet its early evolutionary origins are unknown. Here, we present a comprehensive reconstruction of the PARP family’s history across the plant kingdom. Our phylogenomic analysis reveals that PARP evolution ignited during the bryophyte radiation, expanding from a single ancestral algal gene into three distinct subfamilies (PARP1, PARP2, and PARP3). This diversification was driven by structural innovations in DNA-binding domains and a rewiring of transcriptional networks to respond to terrestrial challenges. We provide direct experimental support for this hypothesis through functional analysis of PARPs from the extremotolerant moss Syntrichia caninervis. We show that its PARP proteins provide multifaceted protection against UV radiation, heat, and genotoxic agents, and that recently duplicated PARP2 genes are already diverging in function. Our work pinpoints the molecular adaptations in a key DNA repair family that enabled the greening of Earth and uncovers novel genetic targets for enhancing crop resilience. Full article

Complete mitochondrial genomes (mitogenomes) are widely utilized molecular resources for phylogenetic studies. Although research on Spariformes mitogenomes has advanced significantly, there is still relatively little information regarding the molecular data and taxonomic placement of the families Nemipteridae and Lethrinidae. We report and annotate the first complete mitogenomes of Pentapodus caninus (16,866 bp; Nemipteridae) and Lethrinus olivaceus (16,792 bp; Lethrinidae), thereby expanding mitogenomic coverage in two families with limited available genomic data. Both assembled mitogenomes display the canonical vertebrate architecture, comprising 37 functional genes (13 protein-coding genes, 22 tRNAs, and 2 rRNAs) and a control region, with conserved synteny and strand asymmetry (only ND6 and eight tRNAs are light-strand encoded). While ATG serves as the primary initiation codon for most PCGs, COX1 employs an alternative GTG start codon. Structural analysis of tRNAs revealed that most sequences adopt the standard cloverleaf conformation, with the exception of tRNA-Ser^AGY, which lacks the dihydrouridine (DHU) arm. A rare tandem duplication of tRNA-Val in Lethrinus species highlights the structural variability of spariform mitochondrial genomes. Furthermore, phylogenomic reconstruction using the concatenated 13 protein-coding gene dataset recovered Nemipteridae and Sparidae as sister taxa. In this topology, Lethrinidae was identified as the earliest diverging lineage, basal to the Nemipteridae–Sparidae grouping. Our results not only advance our understanding of the origin and evolution of Spariformes, but also provide valuable information for the molecular phylogeny and taxonomy of teleostean species. Full article

The Raspy crickets are an interesting group of nocturnal animals that bear femoral-abdominal stridulation and spin silk from the mouthparts. Gryllacridid classification is the subject of ongoing discussion. Here, we present the first mitogenomic sequences for three Ocellarnaca taxa: O. braueri (15,597 bp), O. fuscotessellata (15,607 bp), and O. emeiensis (16,510 bp). Three mitochondrial genomes exhibited the conventional metazoan gene and conserved the characteristic gene order across Gryllacrididae species. Evolutionary selection analyses showed that atp8 was the least evolutionarily constrained mitochondrial gene, whereas cox1 was the most conserved across lineages. The three Ocellarnaca species harbored 5–8 mitochondrial DNA sequence repeats (mtSSRs), falling within the 1–8 range detected in all analyzed Gryllacrididae species. Magnigryllacris and Ocellarnaca exhibited higher mtSSR counts than related genera sharing analogous male abdominal apex morphology. Phylogenomic analyses of 35 mitogenomes from 21 Gryllacrididae species supported Ocellarnaca as monophyletic and a sister to Magnigryllacris (bootstrap = 100%), with O. fuscotessellata resolved as sister to the clade (O. sp. + (O. emeiensis + O. braueri)). This study expands the mitogenomic resources for Ocellarnaca, which will facilitate further resolution of phylogenetic reconstruction within this genus and across Gryllacrididae genera. Full article

Plant genetics and chemotaxonomic analysis are considered key parameters in understanding evolution, plant diversity and adaptation. Korean Peninsula has a unique biogeographical landscape that supports various aromatic plant species, each with considerable ecological, ethnobotanical, and pharmacological significance. This review aims to provide a comprehensive overview of the chemotaxonomic traits, biological activities, phylogenetic relationships and potential applications of Korean aromatic plants, highlighting their significance in more accurate identification. Chemotaxonomic investigations employing techniques such as gas chromatography mass spectrometry, high-performance liquid chromatography, and nuclear magnetic resonance spectroscopy have enabled the identification of essential oils and specialized metabolites that serve as valuable taxonomic and diagnostic markers. These chemical traits play essential roles in species delimitation and in clarifying interspecific variation. The biological activities of selected taxa are reviewed, with emphasis on antimicrobial, antioxidant, anti-inflammatory, and cytotoxic effects, supported by bioassay-guided fractionation and compound isolation. In parallel, recent advances in phylogenetic reconstruction employing DNA barcoding, internal transcribed spacer regions, and chloroplast genes such as rbcL and matK are examined for their role in clarifying taxonomic uncertainties and inferring evolutionary lineages. Overall, the search period was from year 2001 to 2025 and total of 268 records were included in the study. By integrating phytochemical profiling, pharmacological evidence, and molecular systematics, this review highlights the multifaceted significance of Korean endemic aromatic plants. The conclusion highlights the importance of multidisciplinary approaches including metabolomics and phylogenomics in advancing our understanding of species diversity, evolutionary adaptation, and potential applications. Future research directions are proposed to support conservation efforts. Full article

Phylogenetic relationships within the subtribe Arethusinae (Arethuseae: Epidendroideae: Orchidaceae) remain unresolved, with particular uncertainty surrounding the phylogenetic positions of Anthogonium gracile and Eleorchis japonica. The monophyly of this subtribe remains contentious, making it one of the challenging taxa in Orchidaceae phylogenetics. In this study, we sequenced and analyzed the complete plastome sequences of A. gracile and E. japonica for the first time, aiming to elucidate their plastome characteristics and phylogenetic relationships. Both plastomes exhibited a conserved quadripartite structure, with 158,358 bp in A. gracile and 152,432 bp in E. japonica, and GC contents of 37.1% and 37.3%, respectively. Comparative analyses revealed strong structural conservation, but notable gene losses: E. japonica lacked seven ndh genes (ndhC/D/F/G/H/I/K), whereas A. gracile retained a complete ndh gene set. Repetitive sequence analysis identified an abundance of simple sequence repeats (68 and 77), tandem repeats (43 and 30), and long repeats (35 and 40). Codon usage displayed a bias toward the A/U termination, with leucine and isoleucine being the most frequent. Selection pressure analysis indicated that 68 protein-coding genes underwent purifying selection (Ka/Ks < 1), suggesting evolutionary conservation of plastome protein-coding genes. Nucleotide diversity analysis highlighted six hypervariable regions (rps8-rpl14, rps16-trnQ^UUG, psbB-psbT, trnT^UGU-trnL^UAA, trnF^GAA-ndhJ, and ycf1), suggesting their potential as molecular markers. Phylogenomic reconstruction, using complete plastome sequences, (ML, MP, and BI) indicated that Arethusinae was non-monophyletic. A. gracile formed a sister relationship with Mengzia foliosa and E. japonica, whereas Arundina graminifolia exhibited a sister relationship with Coelogyninae members. These results shed new light on the plastome characteristics and phylogenetic relationships of Arethusinae. Full article

Tropidia, a type genus of Tropidieae (Orchidaceae, Epidendroideae), represents an important lineage for investigating plastome evolution and phylogenetic relationships within Epidendroideae. Despite its importance, the lack of available plastid genomic data has hindered comprehensive analyses of its genome structure and phylogenetic relationships. In this study, we assembled and characterized the complete plastid genomes of Tropidia angulosa and T. nipponica, providing valuable insights into plastome evolution and phylogenetic placement of Tropidieae. The plastomes of T. angulosa and T. nipponica exhibited a highly conserved quadripartite structure, sharing similar genomic size (161,395 bp and 160,801 bp) and GC content (36.87% and 36.90%). Both plastomes contained identical gene content and gene order, with 79 protein-coding genes (PCGs), 30 tRNA genes, and four rRNA genes. A total of 169 simple-sequence repeats (SSRs) and 92 long-sequence repeats (LSRs) were identified, most of which were distributed in large single-copy (63.91% and 66.30%) and non-coding regions (83.43% and 65.22%). Comparative plastomes analyses revealed the overall structural stability among photosynthetic lineages, whereas structural variation was primarily detected in mycoheterotrophic lineages. Phylogenomic reconstruction based on plastid-coding sequences revealed that Tropidieae occupies a relatively isolated phylogenetic position within Epidendroideae. These findings contribute to a more comprehensive understanding of plastome evolution and the phylogenetic framework of Epidendroideae. Full article

Citrobacter braakii can colonize the intestinal tract of humans and animals and occasionally act as opportunistic pathogen. Although isolated from food and the environment, its potential as a foodborne pathogen remains uncertain. Twenty C. braakii isolates were previously collected from salami and soft cheese artisanal productions. In the present study, the potentialities of C. braakii as a food safety hazard were explored by a genomic comparison of C. braakii newly sequenced genomes with publicly available genomes, including those of clinical relevance, and a pathogenicity assessment in Galleria mellonella as an in vivo infection model. Phylogenomic reconstruction revealed that one salami clone and two C. braakii genomes of the soft cheese production were closely related (from 11 to 28 core SNP differences) to C. braakii publicly available clinical genomes. All genomes carried the chromosomally located bla_CMY and/or qnrB genes and were resistant to cephalosporins and/or had reduced susceptibility to ciprofloxacin. G. mellonella larvae showed 90% mortality after challenge with C. braakii strains carrying the vex and tvi operons coding for the capsular polysaccharide (Vi antigen), in comparison to 40% of strains lacking these two operons. The high mortality rate of vex- and tvi-positive C. braakii isolated from food processing plants suggests C. braakii to be a possible foodborne hazard. Full article

The genus Rhododendron presents significant challenges for systematic classification due to extensive hybridization and adaptive radiation. Here, we employed double-digest restriction site-associated DNA sequencing (ddRAD-seq) to resolve phylogenetic relationships among nine ecologically significant Rhododendron species (34 accessions) endemic to Zhejiang Province, China, a biodiversity hotspot for this genus. Using R. simsii as the reference genome, we generated 39.40 Gb of high-quality sequencing data with a Q30 score of 96.65% and a GC content of 39.63%, achieving an average alignment rate of 92.79%. Through stringent filtering (QD ≥ 2, MQ ≥ 40), we identified 14,048,702 genome-wide single nucleotide polymorphism (SNP), predominantly characterized by the mutation types T:A>C:G and C:G>T:A. The widespread R. simsii and R. simsii var. putuoense exhibited significant genetic diversity, whereas the low-altitude widespread R. molle and the endemic R. simiarum exhibited lower genetic diversity. Moderate genetic differentiation (F_st = 0.097) was observed between R. simsii and R. simsii var. putuoense, while substantial genetic differentiation was detected among the other Rhododendron species. Principal component analysis (PCA), combined with phylogenomic reconstruction, demonstrated that the Rhododendron genus can be stratified into six well-supported genetic clades. Furthermore, this study provides the first genomic validation of the sibling relationship between R. simsii and its variety, R. simsii var. putuoense, and clarifies the systematic position of R. huadingense, suggesting that it should be classified as a new subgenus. This study establishes ddRAD-seq as a cost-effective tool, providing both a theoretical framework for SNP-based phylogenetics and critical insights for conserving China’s azalea biodiversity. Full article

The living gymnosperms include about 1200 species in five major groups: cycads, ginkgo, gnetophytes, Pinaceae (conifers I), and cupressophytes (conifers II). Molecular phylogenetic studies have yet to reach a unanimously agreed-upon relationship among them. Moreover, cytonuclear phylogenetic incongruence has been repeatedly observed in gymnosperms. We collated a comprehensive dataset from available genomes of 17 gymnosperms across the five major groups and added our own high-quality assembly of a species from Podocarpaceae (the second largest conifer family) to increase sampling width. We used these data to infer reconciled nuclear species phylogenies using two separate methods to ensure the robustness of our conclusions. We also reconstructed organelle phylogenomic trees from 42 mitochondrial and 82 plastid genes from 38 and 289 gymnosperm species across the five major groups, respectively. Our nuclear phylogeny consistently recovers the Ginkgo–cycads clade as the first lineage split from other gymnosperm clades and the Pinaceae as sister to gnetophytes (the Gnepines hypothesis). In contrast, the mitochondrial tree places cycads as the earliest lineage in gymnosperms and gnetophytes as sister to cupressophytes (the Gnecup hypothesis) while the plastomic tree supports the Ginkgo–cycads clade and gnetophytes as the sister to cupressophytes. We also examined the effect of mitochondrial RNA editing sites on the gymnosperm phylogeny by manipulating the nucleotide and amino acid sequences at these sites. Only complete removal of editing sites has an effect on phylogenetic inference, leading to a closer congruence between mitogenomic and nuclear phylogenies. This suggests that RNA editing sites carry a phylogenetic signal with distinct evolutionary traits. Full article

New Caledonia is a biodiversity hotspot with flora closely related to that of Australia and has received considerable attention. Endiandra (Cryptocaryeae; Lauraceae) is distributed from tropical Asia to Oceania, including New Caledonia, with northeastern Australia and New Guinea as diversity centers, but the genus in New Caledonia remains understudied. Here, four species of Endiandra native to New Caledonia were sequenced, and their complete plastome sequences were analyzed. A plastome-based phylogenomic tree of Cryptocaryeae was reconstructed, and divergence times were estimated. The phylogenomic tree supports the monophyly of Endiandra. Interestingly, the species of Endiandra from New Caledonia were grouped into two separate subclades, with one subclade including three species and the other subclade containing only one species. The stem and crown ages of the first subclade were 33.18 Ma and 14.5 Ma, respectively, and the second subclade diverged by approximately 10.36 Ma. The structural characteristics of the newly sequenced plastomes were compared with those of Beilschmiedia species from different continents. The results indicate that the plastome sequences of the four species of Endiandra are longer than those of Beilschmiedia. Additionally, Endiandra has more simple sequence repeats (SSRs) than Beilschmiedia, though the difference is slight. The Guanine-Cytosine (GC) content of Endiandra was lower than that of Beilschmiedia. Five highly variable regions were identified, including matK-rps16, ycf1, petA-psbJ, petN-psbM, and ndhF. The Endiandra species in New Caledonia originated through long-distance dispersal followed by local divergence, rather than vicariance. Additionally, we identified at least two instances of floristic exchange between New Caledonia and Australia. Our study provides further evidence for understanding the biogeographic history between these two regions. Full article

The mostly Holarctic genus Temnothorax (Hymenoptera, Formicidae) is the most diverse ant genus in temperate regions. The Mediterranean, a biodiversity hotspot of rare ant species, hosts over 150 Temnothorax taxa, including several short-range endemics. Over the last few years, phylogenomic reconstructions and integrative taxonomy have significantly improved the understanding of global Temnothorax diversity, but much taxonomic work is still needed in the Mediterranean region. Here, we present the integrative description of a new species of the genus, discovered in the central Mediterranean island of Sicily: Temnothorax siculus sp. n. is defined and compared to congeneric species integrating morphometrics and phylogenomics. It is a ground-nesting, lowland species, of which workers were regularly observed foraging on bushes and small trees. In the global phylogeny, covering all the main lineages of the region, it belongs to the Palearctic clade and is related to the tuberum and unifasciatus complexes. Morphological separation from other Sicilian Temnothorax species can generally be achieved on qualitative characters, but we also provide morphometric discriminant functions to separate it from T. apenninicus and especially T. unifasciatus. Temnothorax siculus has been rarely collected but appears to be widespread in Sicily, and may occur in neighboring regions. Full article

Background/Objectives: Freshwater shrimps of the family Atyidae, particularly the hyperdiverse genus Caridina, are keystone decomposers in tropical aquatic ecosystems and valuable aquaculture resources. However, their evolutionary relationships remain unresolved due to conflicting morphological and molecular evidence. Here, we sequenced and characterized the complete mitochondrial genome of Caridina mariae (Tiger Shrimp), aiming to (1) elucidate its genomic architecture, and (2) reconstruct a robust phylogeny of Caridea using 155 decapod species to address long-standing taxonomic uncertainties. Methods: Muscle tissue from wild-caught C. mariae (voucher ID: KIZ-2023-001, Guangdong, China) was subjected to Illumina NovaSeq 6000 sequencing (150 bp paired-end). The mitogenome was assembled using MITObim v1.9, annotated via MITOS2, and validated by PCR. Phylogenetic analyses employed 13 protein-coding genes under Bayesian inference (MrBayes v3.2.7; 10⁶ generations, ESS > 200) and maximum likelihood (RAxML v8.2.12; 1000 bootstraps), with Harpiosquilla harpax as the outgroup. The best-fit substitution model (MtZoa + F + I + G4) was selected via jModelTest v2.1.10. Results: The 15,581 bp circular mitogenome encodes 37 genes (13 PCGs, 22 tRNAs, and 2 rRNAs) and an A + T-rich control region (86.7%). Notably, trnS1 lacks the dihydrouracil arm—a rare structural deviation in Decapoda. The 13 PCGs exhibit moderate nucleotide skew (AT = 0.030; GC = −0.214), while nad5, nad4, and nad6 show significant GC-skew. Phylogenomic analyses strongly support (PP = 1.0; BS = 95) a novel sister-group relationship between Halocaridinidae and Typhlatyinae, contradicting prior morphology-based classifications. The monophyly of Penaeoidea, Astacidea, and Caridea was confirmed, but Eryonoidea and Crangonoidea formed an unexpected clade. Conclusions: This study provides the first mitogenomic framework for C. mariae, revealing both conserved features (e.g., PCG content) and lineage-specific innovations (e.g., tRNA truncation). The resolved phylogeny challenges traditional Caridea classifications and highlights convergent adaptation in freshwater lineages. These findings offer molecular tools for the conservation prioritization of threatened Caridina species and underscore the utility of mitogenomics in decapod systematics. Full article

The evolutionary history of the Caribbean candelabrum octocorals from the genus Eunicea (Plexauridae: Octocorallia) remains unknown despite their high diversity and abundance in reef environments. Understanding the evolutionary relationships between and within the Eunicea species is critical to accurately measuring the group diversity. Furthermore, this group has a high potential for cryptic diversity and new species, particularly given the rich morphological variability. Conventional molecular markers, however, have not provided a precise positioning for the species inside the genus. Here, we provide the first phylogenomic reconstruction of these candelabrum octocorals employing NextRAD, a reduced-representation sequencing technique, to generate thousands of SNPs. We include 15 morphospecies sampled between valid and new species throughout the Caribbean. At large, the phylogeny is well supported and resolved. In total, 13 species-level clades are discernible, including two lineages with demonstrated genetic and morphological variation that are considered and described as two new species, Eunicea criptica sp. nov. and E. colombiensis sp. nov., both previously assigned as E. clavigera and the second as the “thick morphotype”, thereby increasing the diversity of the group. Understanding the magnitude of species diversity within Eunicea is essential for directing conservation initiatives and clarifying the biological processes in reef ecosystems. Full article