Search

Background: Lasianthus species are widely used in traditional Chinese folk medicine with high medicinal value. However, source materials and herbarium specimens are often misidentified due to morphological characteristics and commonly used DNA barcode fragments are not sufficient for accurately identifying Lasianthus species. To improve the molecular methods for distinguishing among Lasianthus species, we report the complete chloroplast (CP) genomes of Lasianthus attenuatus, Lasianthus henryi, Lasianthus hookeri, Lasianthus sikkimensis, obtained via high-throughput Illumina sequencing. Results: These showed CP genomes size of 160164-160246 bp and a typical quadripartite structure, including a large single-copy region (86675–86848 bp), a small single-copy region (17177–17326 bp), and a pair of inverted repeats (28089–28135 bp). As a whole, the gene order, GC content and IR/SC boundary structure were remarkably similar among of the four Lasianthus CP genomes, the partial gene length and IR, LSC and SSC regions length are still different. The average GC content of the CP genomes was 36.71–36.75%, and a total of 129 genes were detected, including 83 different protein-coding genes, 8 different rRNA genes and 38 different tRNA genes. Furthermore, we compared our 4 complete CP genomes data with publicly available CP genome data from six other Lasianthus species, and we initially screened eleven highly variable region fragments were initially screened. We then evaluated the identification efficiency of eleven highly variable region fragments and 5 regular barcode fragments. Ultimately, we found that the optimal combination fragment' ITS2 + psaI-ycf4' could authenticated the Lasianthus species well. Additionally, the results of genome comparison of Rubiaceae species showed that the coding region is more conservative than the non-coding region, and the ycf1 gene shows the most significant variation. Finally, 49 species of CP genome sequences belonging to 16 genera of the Rubiaceae family were used to construct phylogenetic trees. Conclusions: Our research is the first to analyze the chloroplast genomes of four species of Lasianthus in detail and we ultimately determined that the combination fragment' ITS2 + psaI-ycf4' is the optimal barcode combination for identifying the genus of Lasianthus. Meanwhile, we gathered the available CP genome sequences from the Rubiaceae and used them to construct the most comprehensive phylogenetic tree for the Rubiaceae family. These investigations provide an important reference point for further studies in the species identification, genetic diversity, and phylogenetic analyses of Rubiaceae species. [ABSTRACT FROM AUTHOR]

Introduction: Gelidocalamus Wen is a small yet taxonomically challenging genus within the Arundinarieae tribe. Recent molecular studies have suggested it may not be monophyletic. However, limited species sampling and insufficient molecular marker information have resulted in poorly resolved phylogenetic relationships within this genus. Methods: The complete chloroplast genomes covering all 16 species and one variant of Gelidocalamus were sequenced, and comparative analyses were conducted. Phylogenetic analyses were performed using different molecular markers, including chloroplast data, the nuclear ribosomal DNA (nrDNA) repeats region, and 29 mitochondrial protein-coding genes. Additionally, the divergence times of Gelidocalamus were estimated to reveal their evolutionary history. Results: The plastomes of Gelidocalamus ranged in size from 139,500 bp to 139,801 bp, with a total of 137 identified genes, including 90 protein-coding genes, 39 tRNA genes, and 8 rRNA genes. The size of the nrDNA repeats ranged from 5,802 bp to 5,804 bp. Phylogenetic analysis based on chloroplast data revealed that Gelidocalamus is polyphyletic, with different subclades distributed within the IV and V clades. However, phylogenetic analysis based on nrDNA and mitochondrial genes did not effectively resolve the relationships within the genus. Discussion: Comparative analysis of chloroplast genomes indicated that Gelidocalamus shares a high degree of similarity with closely related genera in terms of chloroplast genome collinearity, codon usage bias, and repetitive sequences. Divergence time estimation suggests that it is a relatively young group, with all members appearing successively over the past four million years. The complex phylogenetic patterns may arise from the rapid radiation of Arundinarieae. This study provides a preliminary foundation for further in-depth research on the phylogeny, genomic structural features, and divergence times of this genus. [ABSTRACT FROM AUTHOR]

Background: The genus Amorphophallus (Araceae) contains approximately 250 species, most of which have high ecological and economic significance. The chloroplast genome data and the comprehensive analysis of the chloroplast genome structure of Amorphophallus is limited. In this study, four chloroplast genomes of Amorphophallus were sequenced and assembled. For the first time, comparative analyses of chloroplast genomes were conducted on the 13 Amorphophallus species in conjunction with nine published sequences. Results: The Amorphophallus chloroplast genomes exhibited typical quadripartite structures with lengths ranging from 164,417 to 177,076 bp. These structures consisted of a large single copy (LSC, 90,705 − 98,561 bp), a small single copy (SSC, 14,172 − 21,575 bp), and a pair of inverted repeats (IRs, 26,225 − 35,204 bp). The genomes contain 108 − 113 unique genes, including 76 − 79 protein-coding genes, 28 − 29 tRNA genes, and 4 rRNA genes. The molecular structure, gene order, content, codon usage, long repeats, and simple sequence repeats (SSRs) within Amorphophallus were generally conserved. However, several variations in intron loss and gene expansion on the IR-SSC boundary regions were found among these 13 genomes. Four mutational hotspot regions, including trnM-atpE, atpB, atpB-rbcL and ycf1 were identified. They could identify and phylogeny future species in the genus Amorphophallus. Positive selection was found for rpl36, ccsA, rpl16, rps4, rps8, rps11, rps12, rps14, clpP, rps3, ycf1, rpl20, rps2, rps18, rps19, atpA, atpF, rpl14, rpoA, rpoC1, rpoC2 and rps15 based on the analyses of Ka/Ks ratios. Phylogenetic inferences based on the complete chloroplast genomes revealed a sister relationship between Amorphophallus and Caladieae. All Amorphophallus species formed a monophyletic evolutionary clade and were divided into three groups, including CA-II, SEA, and CA-I. Amorphophallus albus, A. krausei, A. kachinensis and A. konjac were clustered into the CA-II clade, A. paeoniifolius and A. titanum were clustered into the SEA clade, A. muelleri 'zhuyajin1', Amorphophallus sp, A. coaetaneus, A. tonkinensis and A. yunnanensis were clustered into CA- I clade. Conclusions: The genome structure and gene content of Amorphophallus chloroplast genomes are consistent across various species. In this study, the structural variation and comparative genome of chloroplast genomes of Amorphophallus were comprehensively analyzed for the first time. The results provide important genetic information for species classification, identification, molecular breeding, and evolutionary exploration of the genus Amorphophallus. [ABSTRACT FROM AUTHOR]

Diploid lines (2n = 2x = 24) derived from tetraploid potato cultivars have been utilized to hybridize with wild diploid potato species, yielding fertile offsprings. Utilizing the pollen of Solanum tuberosum Group Phureja, such as IVP101, IVP35 and IVP48, as an inducer for wide hybridization with tetraploid cultivars represents a common method for producing diploids. In this study, we created a distant hybridization induced population of tetraploid potato cultivar Cooperation 88 (C88) and IVP101, and screened all diploids using flow cytometry and ploidyNGS. We investigated the genetic composition of chloroplast and nuclear genomes in 43 diploid offsprings. We found that all diploid offsprings share the same chloroplast genomic sequence as C88 and no evidence of paternal chloroplast inheritance was found. Used SNP data to calculate the theoretical introgression index of IVP101 with diploid offsprings. The results showed that the inducer's nuclear genome was involved in the nuclear genome of the diploid offsprings with purple stem trait, indicating that the inducer nuclear genome was not completely eliminated in the nuclear genome during distant hybridization. Furthermore, we conducted a comparative analysis of the chloroplast genomes of the Solanum genus. The results indicated that (1) the chloroplast genome sizes of the 14 Solanum species ranged from 154,289 bp to 155,614 bp, with a total number of genes ranging 128-141, and with ycf 1 and rps 19 pseudogenes appearing at the IRB/SSC and IRA/LSC boundaries, respectively; (2) eight divergent hotspots distributed in the LSC and SSC regions of the Solanum chloroplast genomes were identified; (3) positive selection was detected in the clp P, rbc L, rps 15, and rps 4 genes, likely contributing to the adaptation of Solanum species to different habitats. These results reveal the variation and evolutionary characteristics of chloroplast genomes in Solanum plants. [ABSTRACT FROM AUTHOR]

Background: Cephalanthera 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. Results: In 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. Conclusions: This 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. [ABSTRACT FROM AUTHOR]

Background: Pepper (Capsicum pubescens), one of five domesticated pepper species, has unique characteristics, such as numerous hairs on the epidermis of its leaves and stems, black seeds, and vibrant purple flowers. To date, no studies have reported on the complete assembly of the mitochondrial genome (mitogenome) of C. pubescens. Understanding the mitogenome is crucial for further research on C. pubescens. Results: In our study, we successfully assembled the first mitogenome of C. pubescens, which was assigned the GenBank accession number OP957066. This mitogenome has a length of 454,165 bp and exhibits the typical circular structure observed in most mitogenomes. We annotated a total of 70 genes, including 35 protein-coding genes (PCGs), 30 tRNA genes, 3 rRNA genes, and 2 pseudogenes. Compared to the other three pepper mitogenomes (KJ865409, KJ865410, and MN196478), C. pubescens OP957066 exhibited four unique PCGs (atp4, atp8, mttB, and rps1), while two PCGs (rpl10 and rps3) were absent. Notably, each of the three pepper mitogenomes from C. annuum (KJ865409, KJ865410, and MN196478) experienced the loss of four PCGs (atp4, atp8, mttB, and rps1). To further explore the evolutionary relationships, we reconstructed a phylogenetic tree using the mitogenomes of C. pubescens and fourteen other species. Structural comparison and synteny analysis of the above four pepper mitogenomes revealed that C. pubescens shares high sequence similarity with KJ865409 and that C. pubescens has rearranged with the other three pepper mitogenomes. Interestingly, we observed 72 similar sequences between the mitochondrial and chloroplast genomes, which accounted for 12.60% of the mitogenome, with a total length of 57,207 bp. These sequences encompassed 12 tRNA genes and the rRNA gene (rrn18). Remarkably, selective pressure analysis suggested that the nad5 gene underwent obvious positive selection. Furthermore, a single-base mutation in three genes (nad1, nad2, and nad4) resulted in an amino acid change. Conclusion: This study provides a high-quality mitogenome of pepper, providing valuable molecular data for future investigations into the exchange of genetic information between pepper organelle genomes. [ABSTRACT FROM AUTHOR]

Background: Astragalus membranaceus (Fisch.) Bunge is one of the most well-known tonic herbs in traditional Chinese medicine, renowned for its remarkable medicinal value in various clinical contexts. The corresponding chloroplast (cp) and nuclear genomes have since been accordingly sequenced, providing valuable information for breeding and phylogeny studies. However, the mitochondrial genome (mitogenome) of A. membranaceus remains unexplored, which hinders comprehensively understanding the evolution of its genome. Results: For this study, we de novo assembled the mitogenome of A. membranaceus (Fisch.) Bunge var. mongholicus (Bunge) P. K. Hsiao using a strategy integrating Illumina and Nanopore sequencing technology and subsequently performed comparative analysis with its close relatives. The mitogenome has a multi-chromosome structure, consisting of two circular chromosomes with a total length of 398,048 bp and an overall GC content of 45.3%. It encodes 54 annotated functional genes, comprising 33 protein-coding genes (PCGs), 18 tRNA genes, and 3 rRNA genes. An investigation of codon usage in the PCGs revealed an obvious preference for codons ending in A or U (T) bases, given their high frequency. RNA editing identified 500 sites in the coding regions of mt PCGs that exhibit a perfect conversion of the base C to U, a process that tends to lead to the conversion of hydrophilic amino acids into hydrophobic amino acids. From the mitogenome analysis, a total of 399 SSRs, 4 tandem repeats, and 77 dispersed repeats were found, indicating that A. membranaceus possesses fewer repeats compared to its close relatives with similarly sized mitogenomes. Selection pressure analysis indicated that most mt PCGs were purifying selection genes, while only five PCGs (ccmB, ccmFc, ccmFn, nad3, and nad9) were positive selection genes. Notably, positive selection emerged as a critical factor in the evolution of ccmB and nad9 in all the pairwise species comparisons, suggesting the extremely critical role of these genes in the evolution of A. membranaceus. Moreover, we inferred that 22 homologous fragments have been transferred from cp to mitochondria (mt), in which 5 cp-derived tRNA genes remain intact in the mitogenome. Further comparative analysis revealed that the syntenic region and mt gene organization are relatively conserved within the provided legumes. The comparison of gene content indicated that the gene composition of Fabaceae mitogenomes differed. Finally, the phylogenetic tree established from analysis is largely congruent with the taxonomic relationships of Fabaceae species and highlights the close relationship between Astragalus and Oxytropis. Conclusions: We provide the first report of the assembled and annotated A. membranaceus mitogenome, which enriches the genetic resources available for the Astragalus genus and lays the foundation for comprehensive exploration of this invaluable medicinal plant. [ABSTRACT FROM AUTHOR]

Background: Capsicum (Solanaceae) is a globally important vegetable crop and is also used therapeutically in traditional medicine systems. However, little is known of the genetic variation within the commonly grown cultivars, the evolutionary relationships and differences in the chloroplast (cp.) genomes between Capsicum species remain unclear. Results: The cp. genomes of 32 Capsicum varieties in three species from 6 countries were investigated. The cp. genome of Capsicum was found to be ~ 156 kb in length and to contain 113 unique genes, of which 79 encoded proteins, 30 encoded transfer tRNAs, and 4 were for ribosomal RNAs. The 32 varieties that we chose for study represented 13 genotypes, containing a total of 608 indels, 83 SNPs, 47 SSRs and 281–306 repeat sequences. We then included several previously sequenced Capsicum cp. genomes, and found that the nine investigated species showed a number of differences in the characteristics of the four IR boundaries, and it was the non-coding regions that contained the most variable regions. We conducted a phylogenetic reconstruction using the cp. genomes of 43 representative species of Solanaceae, and the resulting phylogeny generally reflected the currently accepted classification, with the species of the pungent group having close relationship with one another. Conclusions: This study provides a comprehensive analysis of Capsicum chloroplast genomes, revealing significant variations in IR boundaries and other genomic features. These findings enhance our understanding of Capsicum evolution and genetic diversity. [ABSTRACT FROM AUTHOR]

Scutellaria strigillosa Hemsl., known for its traditional use in Chinese herbal medicine, is valued for heat-clearing and detoxifying, promoting diuresis, reducing swelling, alleviating pain, and preventing miscarriage. Despite its historical use, comprehensive studies on pharmacophylogenetic analysis, including genetic and chemical profiles and the antimicrobial activity of S. strigillosa are still lacking. Understanding these aspects is crucial for fully realizing its therapeutic potential and ensuring sustainable use. This study aims to elucidate these aspects through comparative genomics, metabolomics, and antimicrobial assays with Scutellaria baicalensis Georgi and Scutellaria barbata D. Don. The chloroplast genome of S. strigillosa was assembled, measuring 152,533 bp, and revealing a high degree of conservation, especially in the protein-coding regions, and identified four regions trnK(UUU) - rps16 , trnN(GUU) -t rnR(ACG) , accD - psaI , psbE - petL) of variability that could serve as phylogenetic markers. The phylogenetic analysis revealed a closer genetic relationship of S. strigillosa with S. tuberifera and S. scordifolia than traditionally classified, suggesting a need for taxonomic reevaluation within the genus. UPLC-Q-TOF-MS analysis in negative ion mode was used to explore the chemical diversity among these species, revealing distinct variations in their chemical compositions. S. strigillosa shared a closer chemical profile with S. barbata , aligning with phylogenetic findings. Metabolomic identification through Progenesis QI software resulted in the tentative identification of 112 metabolites, including a substantial number of flavonoids, diterpenoids, iridoid glycosides, phenylethanoid glycosides, and others. HPLC analysis further detailed the concentrations of 12 actives across the species, highlighting the variation in compound content. S. strigillosa shows antibacterial activity against Staphylococcus aureus and Pseudomonas aeruginosa , similar to S. baicalensis root extracts. This research enhances the understanding of the phylogenetic and phytochemical profiles and the antibacterial activity of S. strigillosa , offering new insights into its medicinal properties. The findings suggest a need for taxonomic reevaluation within the genus and underscore the potential antibacterial activity of S. strigillosa for therapeutic applications. Further studies are encouraged to explore its full medicinal potential and contribute to the sustainable development of Scutellaria species. [ABSTRACT FROM AUTHOR]

Background: Habenaria, a genus in the family Orchidaceae, are the nearly cosmopolitan orchids, and most species have significant medicinal and ornamental values. Despite the morphological and molecular data that have been studied in recent years, the phylogenetic relationship is still unclear. Results: We sequenced, assembled, and annotated the chloroplast (cp) genomes of two species (Habenaria aitchisonii Rchb.f. and Habenaria tibetica Schltr.ex Limpricht) of Habenaria grown on the Qinghai-Tibetan Plateau (QTP), and compared them with seven previously published cp genomes which may aid in the genomic profiling of these species. The two genomes ranged from 155,259–155,269 bp in length and both included 132 genes, encoding 86 proteins, 38 tRNAs and 8 rRNAs. In the cp genomes, the tandem repeats (797), SSRs (2195) and diverse loci (3214) were identified. Comparative analyses of codon usage, amino frequency, microsatellite, oligo repeats and transition and transversion substitutions revealed similarities between the species. Moreover, we identified 16 highly polymorphic regions with a nucleotide diversity above 0.02, which may be suitable for robust authentic barcoding and inferring in the phylogeny of Habenaria species. Among the polymorphic regions, positive selection was significantly exerted on several genes, such as cemA, petA, and ycf1. This finding may suggest an important adaptation strategy for the two Habenaria species on the QTP. The phylogenetic relationship revealed that H. aitchisonii and H. tibetica were more closely related to each other than to the other species, and the other seven species were clustered in three groups. In addition, the estimated divergence time suggested that the two species separated from the others approximately 0.39 Mya in the Neogene period. Our findings also suggest that Habenaria can be divided into different sections. Conclusions: The results of this study enriched the genomics resources of Habenaria, and SSR marker may aid in the conservation management of two endangered species. [ABSTRACT FROM AUTHOR]

Background: Halophila beccarii is one of the oldest two generations of seagrass plants and one of the 10 species of seagrass currently at risk of extinction worldwide. Therefore, how to effectively protect the H. beccarii resources from extinction is a huge challenge. Molecular biology research can provide a scientific basis for species conservation. So far, there has been no detailed analysis of the mitochondrial genome of the genus Halophila. Results: The mitochondrial genome of H. beccarii was assembled into 28 circular chromosomes, ranging in length from 41,738 bp to 104,744 bp, with a total length of 1,964,072 bp and a GC content of 46.71%. It contains 39 genes, including 26 protein coding genes, 10 tRNA genes, and 3 rRNA genes. Repeat sequence analysis and prediction of RNA editing sites revealed a total of 850 dispersed repeats, 1,205 simple repeats, 61 tandem repeats, and 120 RNA editing sites. Analysis of codon usage indicates that codons ending in A/U are preferred. Gene migration between the mitochondrial genome and the chloroplast genome was observed through homologous fragment detection. In addition, Ka/Ks analysis showed that most protein coding genes in the mitochondrial genome experienced negative selection, while only the nad3 gene experienced potential positive selection in most Alismatales. Nucleotide polymorphism analysis revealed variations in each gene, with rpl10 being the most significant. In addition, comparative analysis shows that the GC content is conserved, but there are significant differences in the size and structure of mitochondrial genomes among different species of Alismatales. The phylogenetic analysis based on the mitochondrial genome reflects the exact evolutionary and taxonomic status of H. beccarii. Conclusion: In this study, we sequenced and annotated the mitochondrial genome of H. beccarii, and compared it with the mitochondrial genomes of other plants in Alismatales. Our findings enrich the mitogenome database of seagrass plants and highlight the potential for mitochondrial genes to help decipher plant evolutionary history. [ABSTRACT FROM AUTHOR]

Pears constitute an essential temperate crop and are primarily produced through interspecific hybridization owing to self-incompatibility that complicates their breeding history. To address this, we sequenced the complete chloroplast (cp) genomes of 18 Pyrus and one Malu s species using the Illumina HiSeq4000 platform. The cp genomes ranged from 159,885 bp to 160,153 bp and exhibited a conserved circular DNA structure with an average GC content of 36.5%. Each cp genome contained 127 genes, including 83 protein-coding, 36 tRNA, and 8 rRNA genes. Divergence analysis with mVISTA showed high conservation in the coding regions and notable variations in the non-coding regions. All species shared 17 intron-containing genes, with ycf3 and clpP each having two introns. Five intron-containing genes (ndhB , rpl2 , rps12 , trnA-UGC , and trnE-UUC) were located in the inverted repeat regions, while trnL-UAA was located in the large single-copy region, with conserved intron lengths across Pomoideae. We identified polymorphic intron sequences in the rpl22 , petB , clpP , ndhA , and rps16 genes and designed primers for these regions. Notably, the two Pyrus ussuriensis accessions Doonggeullebae and Cheongdangrori showed intron-length polymorphisms despite being classified as the same species. Phylogenetic analysis of the cp genome sequences revealed two major clusters, indicating distinct maternal lineages and evolutionary origins. This study underscores the importance of cp gene polymorphisms in P. fauriei , P. calleryana , P. ussuriensis , and P. pyrifolia , providing valuable insights into Pyrus evolution as well as aiding in the conservation and breeding of pear germplasm. [ABSTRACT FROM AUTHOR]

Gastrodia elata rhizomes have been applied as traditional medicinal materials for thousands of years. In China, G. elata f. elata (red flower and stem, Ge), G. elata f. viridis (green, Gv), and G. elata f. glauca (black, Gg) represent the primary cultivars in artificial cultivation. Although the annual output of G. elata amounts to 150,000 tons, only 20% is Gg. The long production period, low yield, and high quality of Gg led to its extremely high market prices. However, an effective method to identify this crude drug based solely on its morphological or chemical characteristics is lacking. In this study, the complete chloroplast genomes of three G. elata variants were sequenced using the Illumina HiSeq 2500 platform. Another 21 chloroplast genomes from Gastrodia species, which have published in previous reports, were combined and analyzed together. Our results showed that larger genomic sizes, fewer long tandem repeats, and more simple sequence repeats were the major features of the Gg chloroplast genomes. Phylogenetic analysis showed that the Gg samples were separately clustered in a subclade. Moreover, an accession-specific marker was successfully developed and validated for distinguishing additional rhizome samples. Our study provides investigations of the taxonomic relationships of Gastrodia species. The molecular marker will be useful for differentiating Gastrodia products on the market. [ABSTRACT FROM AUTHOR]

Gentiana rigescens, an alpine plant with significant medicinal value, possesses a complex genetic background. However, comprehensive genomic research on G. rigescens is still lacking, particularly concerning its organelle genome. In this study, G. rigescens was studied to sequence the mitochondrial genome (mitogenome) and ascertain the assembly, informational content, and developmental expression of the mitogenome. The mitogenome of G. rigescens was 393,595 bp in length and comprised four circular chromosomes ranging in size from 6646 bp to 362,358 bp. The GC content was 43.73%. The mitogenome featured 30 distinct protein-coding genes, 26 tRNA genes, and 3 rRNA genes. The mitogenome of G. rigescens also revealed 70 SSRs, which were mostly tetra-nucleotides. In addition, 48 homologous fragments were found between the mitogenome and the chloroplast genome, with the longest measuring 23,330 bp. The documentation of the mitochondrial genome of G. rigescens is instrumental in advancing the understanding of its physiological development. Decoding the G. rigescens mitogenome will offer valuable genetic material for phylogenetic research on Gentianaceae and enhance the use of species germplasm resources. [ABSTRACT FROM AUTHOR]

The kiang (Equus kiang) can only be observed in the Qinghai–Tibet Plateau (QTP). The kiang displayed excellent athletic performance in the high‐altitude environment, which attracted wide interest in the investigation of the potential adaptive mechanisms to the extreme environment. Here, we assembled a chromosome‐level genome of the kiang based on Hi‐C sequencing technology. A total of 324.14 Gb clean data were generated, and the chromosome‐level genome with 26 chromosomes (25 + X) and scaffold N50 of 101.77 Mb was obtained for the kiang. The genomic synteny analysis revealed large‐scale chromosomal rearrangement during the evolution process of Equus species. Phylogenetic and divergence analyses revealed that the kiang was the sister branch to the ass and diverged from a common ancestor at approximately 13.5 Mya. The expanded gene families were mainly related to the hypoxia response, metabolism, and immunity. The kiang suffered a significant loss of olfaction‐related genes, which might indicate decreased olfactory sensibility. Positively selected genes (PSGs) detected in the kiang were mainly associated with hypoxia response. Especially, there were two species‐specific missense amino acid mutations in the PSG STAT3 annotated in the hypoxia‐inducible factor 1 signal pathway, which may play an important role in the high‐altitude adaptation of the kiang. Moreover, structure variations in the kiang genome were also identified, which possibly contributed to the high‐altitude adaptation of the kiang. Comparative analysis revealed a lot of species‐specific insertions and deletions in the kiang genome, such as PIK3CB and AKT with 3258 and 189 bp insertions in the intron region, respectively, possibly affecting the expression and regulation of hypoxia‐related downstream pathways. This study provided valuable genomic resources, and our findings help a better understanding of the underlying adaptive strategies to the high‐altitude environment in the kiang. [ABSTRACT FROM AUTHOR]

Reproductive interference, an interspecific interaction in reproductive process that exerts an adverse effect, has gained attention as a contributing factor in promoting exclusive distributions between closely related species. However, detailed studies on the possibility of reproductive interference between native plants are still lacking, presumably because strong reproductive interference can rapidly realize exclusive distributions, leaving the two species apparently independent. Salvia japonica and S. lutescens are found in separate localities at a small scale, although their distributions overlap at a large scale. We investigated the possibility of reproductive interference between them through field surveys, hand-pollination experiments, evaluation of hybrid fertility, cpDNA and nrDNA genotyping, and genome-wide DNA analysis. The field survey results did not reveal apparent negative interaction in competition for pollinator services. Mixed pollination with conspecific pollen and counterpart pollen reduced seed set in S. japonica, and hybrid progeny produced by mixed pollination were less than 20% as fertile compared to the pure species. The DNA genotyping results suggested the possibility of hybridization where their distributions overlap, and the genome-wide DNA analysis results showed clear genetic differentiation between the two species as well as the existence of hybrids. These results suggest that bi-directional reproductive interference between S. japonica and S. lutescens may have led to their present separated distributions at a small scale. [ABSTRACT FROM AUTHOR]

The present study assesses the phylogenetic position of certain Thai members of Gymnema, Gymnemopsis, and Sarcolobus in relation to other known Marsdenieae species. Fifteen accessions newly sequenced from Thailand were added to the dataset of the homologous sequences of 125 accessions of Marsdenieae downloaded from GenBank. In our molecular phylogeny, almost all the delimited major clades and their relationships are largely congruent with those revealed in previous studies. The monophyly of Gymnema (including the former Jasminanthes species) and that of Sarcolobus, as presently circumscribed, are confirmed. The new accessions of these two genera from Thailand are well grouped with the members of their respective genera. Our analyses provide the first molecular evidence for recognition of Gymnemopsis, a small Asian genus that has never been included in the previous phylogenetic studies, as a distinct genus. All elements of Gymnemopsis are retrieved as a well-supported monophyletic group that is strongly supported as sister to Lygisma, another small Asian genus that most closely resembles it in growth habit, color of latex, indumentum on plant parts, corona structure and follicle traits. Combined molecular phylogenetic, morphological and ecological data also support recognition of two new Sarcolobus species from Thailand, Sarcolobus busbanianus sp. nov. and S. flavus sp. nov. Similarities and differences between these new species and their close relative, S. carinatus, are discussed. In addition, this study also reveals the first record for Thailand of Gymnema lacei. Keys to the species of Gymnemopsis (for all members of the genus), Gymnema and Sarcolobus (for Thai members of these genera) are provided. [ABSTRACT FROM AUTHOR]

SUMMARY: Chloroplasts are organelles that are derived from a photosynthetic bacterium and have their own genome. Genome editing is a recently developing technology that allows for specific modifications of target sequences. The first successful application of genome editing in chloroplasts was reported in 2021, and since then, this research field has been expanding. Although the chloroplast genome of several dicot species can be stably modified by a conventional method, which involves inserting foreign DNAs into the chloroplast genome via homologous recombination, genome editing offers several advantages over this method. In this review, we introduce genome editing methods targeting the chloroplast genome and describe their advantages and limitations. So far, CRISPR/Cas systems are inapplicable for editing the chloroplast genome because guide RNAs, unlike proteins, cannot be efficiently delivered into chloroplasts. Therefore, protein‐based enzymes are used to edit the chloroplast genome. These enzymes contain a chloroplast‐transit peptide, the DNA‐binding domain of transcription activator‐like effector nuclease (TALEN), or a catalytic domain that induces DNA modifications. To date, genome editing methods can cause DNA double‐strand break or introduce C:G‐to‐T:A and A:T‐to‐G:C base edits at or near the target sequence. These methods are expected to contribute to basic research on the chloroplast genome in many species and to be fundamental methods of plant breeding utilizing the chloroplast genome. Significance Statement: The current status of recently developed technologies for plastid genome editing is summarized and discussed. This technology offers advantages in precision, inheritability, social and national acceptance, and feasibility across a wider range of species, benefiting both basic biology and future agricultural applications. [ABSTRACT FROM AUTHOR]

Monoclonal antibodies (mAbs) have become indispensable tools in various fields, from research to therapeutics, diagnostics, and industries. However, their production, primarily in mammalian cell culture systems, is cost-intensive and resource-demanding. Microalgae, diverse photosynthetic microorganisms, are gaining attention as a favorable option for manufacturing mAbs and various other recombinant proteins. This review explores the potential of microalgae as a robust expression system for biomanufacturing high-value proteins. It also highlights the diversity of microalgae species suitable for recombinant protein. Nuclear and chloroplast genomes of some microalgae have been engineered to express mAbs and other valuable proteins. Codon optimization, vector construction, and other genetic engineering techniques have significantly improved recombinant protein expression in microalgae. These accomplishments demonstrate the potential of microalgae for biopharmaceutical manufacturing. Microalgal biotechnology holds promise for revolutionizing the production of mAbs and other therapeutic proteins, offering a sustainable and cost-effective solution to address critical healthcare needs. [ABSTRACT FROM AUTHOR]

Background: Arundinelleae is a small tribe within the Poaceae (grass family) possessing a widespread distribution that includes Asia, the Americas, and Africa. Several species of Arundinelleae are used as natural forage, feed, and raw materials for paper. The tribe is taxonomically cumbersome due to a paucity of clear diagnostic morphological characters. There has been scant genetic and genomic research conducted for this group, and as a result the phylogenetic relationships and species boundaries within Arundinelleae are poorly understood. Results: We compared and analyzed 11 plastomes of Arundinelleae, of which seven plastomes were newly sequenced. The plastomes range from 139,629 base pairs (bp) (Garnotia tenella) to 140,943 bp (Arundinella barbinodis), with a standard four-part structure. The average GC content was 38.39%, but varied in different regions of the plastome. In all, 110 genes were annotated, comprising 76 protein-coding genes, 30 tRNA genes, and four rRNA genes. Furthermore, 539 simple sequence repeats, 519 long repeats, and 10 hyper-variable regions were identified from the 11 plastomes of Arundinelleae. A phylogenetic reconstruction of Panicoideae based on 98 plastomes demonstrated the monophyly of Arundinella and Garnotia, but the circumscription of Arundinelleae remains unresolved. Conclusion: Complete chloroplast genome sequences can improve phylogenetic resolution relative to single marker approaches, particularly within taxonomically challenging groups. All phylogenetic analyses strongly support the monophyly of Arundinella and Garnotia, respectively, but the monophylly of Arundinelleae was not well supported. The intergeneric phylogenetic relationships within Arundinelleae require clarification, indicating that more data is necessary to resolve generic boundaries and evaluate the monophyly of Arundinelleae. A comprehensive taxonomic revision for the tribe is necessary. In addition, the identified hyper-variable regions could function as molecular markers for clarifying phylogenetic relationships and potentially as barcoding markers for species identification in the future. [ABSTRACT FROM AUTHOR]

The genus Macadamia in the Proteaceae family includes four species native to Australia. Two of the four species, M. integrifolia and M. tetraphylla, have recently been utilized to generate domesticated macadamia varieties, grown for their edible nuts. To explore diversity in macadamia genetic resources, a total of 166 wild genotypes, representing all four species, were sequenced. The four species were clearly distinguished as four separate clades in a phylogenetic analysis of the nuclear genome (based upon concatenated nuclear gene CDS and SNPs). The two larger species (M. integrifolia and M. tetraphylla) formed a clade, that had diverged from a clade including the smaller species (M. ternifolia and M. jansenii). The greatest diversity in nuclear and chloroplast genomes was found in the more widely distributed M. integrifolia while the rare M. jansenii showed little diversity. The chloroplast phylogeny revealed a much more complex evolutionary history. Multiple chloroplast capture events have resulted in chloroplast genome clades, including genotypes from different species. This suggests extensive reticulate evolution in Macadamia despite the emergence of the four distinct species that are supported by the analysis of their nuclear genomes. The chloroplast genomes showed strong associations with geographical distribution reflecting limited maternal gene movement in these species that have large seeds. The nuclear genomes showed lesser geographical differences, probably reflecting the longer distance pollen movement. This improved understanding of the distribution of diversity in Macadamia will aid in the conservation of these rare species now found in highly fragmented rainforest remnants. [ABSTRACT FROM AUTHOR]

The use of complete organelle genomes, including chloroplast and mitochondrial genomes, is a powerful molecular method for studying biological evolution and gene transfer. However, in the case of Polygonaceae, an important family with numerous edible, medicinal, and ornamental species, the mitochondrial genomes of only three species have been sequenced and analyzed. In this study, we present the mitochondrial and chloroplast genomes of two important Tibetan medicinal plants, Bistorta viviparum and B. macrophyllum. All the organelle genomes are assembled into a single circular structure and contain a common set of 32 protein-coding genes (PCGs). Some genes such as rps2 and ndhF were found to have high nucleotide polymorphism (Pi) in the chloroplast genomes, while cox1, mttB and rps12 showed pronounced Pi values in the mitochondrial genomes. Furthermore, our analysis revealed that most chloroplast genes and mitochondrial PCGs in Polygonaceae plants are under purifying selection. However, a few genes, including the chloroplast gene psaJ and the mitochondrial genes ccmFc, atp8 and nad4, showed positive selection in certain Polygonaceae plants, as indicated by a Ka/Ks ratio greater than one. Structural variation analysis revealed a wealth of differences between the mitochondrial genomes of five Polygonaceae species, with a particularly notable large-scale inversion observed between Reynoutria japonica and Fallopia aubertii. Furthermore, an analysis of the homologous sequences in the chloroplast and mitochondrial genomes revealed that the rps7 has been transferred from the chloroplast to the mitochondrial genome in all five Polygonaceae species. Finally, ecological niche models were constructed for B. viviparum and B. macrophyllum, indicating that mean annual temperature and altitude are the main climatic factors influencing the distribution of both species. Although the current distribution of B. viviparum is significantly wider than that of B. macrophyllum, projections suggest that the optimal growth ranges of both species will expand in the future, with B. macrophyllum potentially exceeding B. viviparum. This study not only contributes to the plastid genome database for Polygonaceae plants, but also provides theoretical insights into the adaptive evolution of these plants. [ABSTRACT FROM AUTHOR]

Background: The family Lauraceae is subdivided into six main lineages: Caryodaphnopsideae, Cassytheae, Cryptocaryeae, Hypodaphnideae, Laureae, and Neocinnamomeae. However, phylogenetic relationships among these lineages have been debatable due to incongruence between trees constructed using nuclear ribosomal DNA (nrDNA) sequences and chloroplast (cp) genomes. As with cp DNA, the mitochondrial (mt) DNA of most flowering plants is maternally inherited, so the phylogenetic relationships recovered with mt genomes are expected to be consistent with that from cp genomes, rather than nrDNA sequences. Results: The mitogenome of Machilus yunnanensis, with a length of 735,392 bp, has a very different genome size and gene linear order from previously published magnoliid mitogenomes. Phylogenomic reconstructions based on 41 mt genes from 92 Lauraceae mitogenomes resulted in highly supported relationships: sisterhood of the Laureae and a group containing Neocinnamomeae and Caryodaphnopsideae, with Cassytheae being the next sister group, followed by Cryptocaryeae. However, we found significant incongruence among the mitochondrial, chloroplast, and nuclear phylogenies, especially for the species within the Caryodaphnopsideae and Neocinnamomeae lineages. Time-calibrated phylogenetic analyses showed that the split between Caryodaphnopsideae and Neocinnamomeae dated to the later Eocene, around 38.5 Ma, Laureae originated in the Late Cretaceous, around 84.9 Ma, Cassytheae originated in the mid-Cretaceous around 102 Ma, and Cryptocaryeae originated in the Early Cretaceous around 116 Ma. From the Late Cretaceous to the Paleocene, net diversification rates significantly increased across extant clades of major lineages, and both speciation rates and net diversification rates continued steady growth towards the present. Conclusions: The topology obtained here for the first time shows that mt genes can be used to support relationships among lineages of Lauraceae. Our results highlight that both Caryodaphnopsideae and Neocinnamomeae lineages are younger than previously thought, likely first diversifying in the Eocene, and species in the other extant lineages of Lauraceae dates in a long-time span from the Early Cretaceous to the Eocene, and the climate of a period of about 90 million years was relatively warm, while the extant species of Lauraceae then continuously diversified with global cooling from the Eocene to the present day. [ABSTRACT FROM AUTHOR]

'Boju' and 'Huaiju' are cultivars of the Chrysanthemum (Chrysanthemum morifolium Ramat.) in the family Asteraceae, valued for their medicinal, tea, and ornamental properties, and valued by individuals. However, the yield and quality of medicinal chrysanthemums are limited by the characteristics of the germplasm resources, including the identification at the varieties and cultivation levels. Currently, research characterizing the chloroplast genomes of medicinal Chrysanthemum flowers is relatively limited. This study conducted chloroplast whole-genome sequencing on two cultivars of Chrysanthemum, 'Boju' and 'Huaiju', and compared them with the previously published chloroplast genomes of 'Hangbaiju' and 'Gongju'. The study analyzed the chloroplast genome structures of these four medicinal Chrysanthemums, identifying mutation hotspots and clarifying their phylogenetic relationships. The chloroplast genome sizes of four medicinal Chrysanthemum cultivation products ranged from 151,057 to 151,109 bp, with GC content ranging from 37.45% to 37.76%. A total of 134 genes were identified, including 89 protein-coding genes, 37 ribosomal RNA genes, and 8 transfer RNA genes. Comparative genomic analysis revealed 159 large repeat sequences, 276 simple sequence repeats, 1 gene, and 8 intergenic regions identified as highly variable regions. Nucleotide diversity (Pi) values were high (≥ 0.004) for the petN-psbM, trnR-UCU-trnT-GGU, trnT-GGU-psbD, ndhC-trnV-UCA, ycf1, ndhI-ndhG, trnL-UGA-rpl32, rpl32-ndhF, and ndhF-ycf1 fragments, aiding in variety identification. Phylogenetic analysis revealed consistent results between maximum likelihood and Bayesian inference trees, showing that the four medicinal Chrysanthemum cultivars, along with their wild counterparts and related species, evolved as a monophyletic group, forming a sister clade to Artemisia and Ajania. Among the six Chrysanthemum species, the wild Chrysanthemum diverged first (Posterior probability = 1, bootstrap = 1,000), followed by Ajania, while C. indicum and C. morifolium clustered together (Bootstrap = 100), indicating their closest genetic relationship. The chloroplast whole-genome data and characteristic information provided in this study can be used for variety identification, genetic conservation, and phylogenetic analysis within the family Asteraceae. [ABSTRACT FROM AUTHOR]

Introduction: Zicaitai (Brassica rapa var. purpuraria) is a Brassica variety renowned for its distinctive taste and rich nutritional profile. In recent years, the mitochondrial genomes of several Brassica species have been documented, but the mitogenome of Zicaitai remains unreported. Methods: In this study, we characterized the Zicaitai mitogenome achieved through the assembly of sequencing reads derived from both the Oxford Nanopore and Illumina platforms. A detailed comparative analysis was carried out with other Brassica species to draw comparisons and contrasts. In-depth analyses of codon usage patterns, instances of RNA editing, and the prevalence of sequence repeats within the mitogenome were also conducted to gain a more nuanced understanding of its genetic architecture. A phylogenetic analysis was performed, utilizing the coding sequences (CDS) from the mitochondrial genome of Zicaitai and that of 20 closely related species/varieties to trace evolutionary connections. Results: The Zicaitai mitogenome is characterized by a circular structure spanning 219,779 base pairs, and it encompasses a total of 59 genes. This gene set includes 33 protein-coding genes, 23 tRNA genes, and 3 rRNA genes, providing a rich foundation for further genomic study. An analysis of the Ka/Ks ratios for 30 protein-coding genes shared by the mitogenomes of Zicaitai and seven other Brassica species revealed that most of these genes had undergone purifying selection. Additionally, the study explored the migration of genes between the chloroplast and nuclear genomes and the mitogenome, offering insights into the dynamics of genetic exchange within the Brassica genus. Discussion: The collective results in this study will serve as a foundational resource, aiding future evolutionary studies focused on B. rapa, and contributing to a broader understanding of the complexities of plant evolution. [ABSTRACT FROM AUTHOR]

Background: Trachelospermum jasminoides has medicinal and ornamental value and is widely distributed in China. Although the chloroplast genome has been documented, the mitochondrial genome has not yet been studied. Results: The mitochondrial genome of T. jasminoides was assembled and functionally annotated using Illumina and nanopore reads. The mitochondrial genome comprises a master circular molecular structure of 605,764 bp and encodes 65 genes: 39 protein-coding genes, 23 transfer RNA (tRNA) genes and 3 ribosomal RNA genes. In addition to the single circular conformation, we found many alternative conformations of the T. jasminoides mitochondrial genome mediated by 42 repetitive sequences. Six repetitive sequences (DRS01–DRS06) were supported by nanopore long reads, polymerase chain reaction (PCR) amplifications, and Sanger sequencing of the PCR products. Eleven homologous fragments were identified by comparing the mitochondrial and chloroplast genome sequences, including three complete tRNA genes. Moreover, 531 edited RNA sites were identified in the protein-coding sequences based on RNA sequencing data, with nad4 having the highest number of sites (54). Conclusion: To our knowledge, this is the first description of the mitochondrial genome of T. jasminoides. Our results demonstrate the existence of multiple conformations. These findings lay a foundation for understanding the genetics and evolutionary dynamics of Apocynaceae. [ABSTRACT FROM AUTHOR]

Orchidantha chinensis T. L. Wu, an endemic species in China, is listed as a key protected wild plant in Guangdong Province. However, the lack of reports on the chloroplast genome and simple sequence repeat (SSR) markers has hindered the assessment of its genetic diversity and conservation strategies. The limited number of molecular markers to assess the genetic diversity of this species, and thus develop proper conservation strategies, highlighted the urgent need to develop new ones. This study developed new SSR markers and investigated genetic variation using 96 samples of O. chinensis from seven populations. Through high-throughput sequencing, a complete chloroplast genome of 134,407 bp was assembled. A maximum-likelihood phylogenetic tree, based on the chloroplast genome, showed that O. chinensis is closely related to Ravenala madagascariensis. The study identified 52 chloroplast SSRs (cpSSRs) and 5094 expressed sequence tag SSRs (EST-SSRs) loci from the chloroplast genome and leaf transcriptome, respectively. Twenty-one polymorphic SSRs (seven cpSSRs and fourteen EST-SSRs) were selected to evaluate the genetic variation in 96 accessions across seven populations. Among these markers, one cpSSR and 11 EST-SSRs had high polymorphism information content (>0.5). Cluster, principal coordinate, and genetic structure analyses indicated that groups G1 and G6 were distinct from the other five groups. However, an analysis of molecular variance showed greater variation within groups than among groups. The genetic distance among the populations was significantly positively correlated with geographical distance. These findings provide new markers for studying the genetic variability of O. chinensis and offer a theoretical foundation for its conservation strategies. [ABSTRACT FROM AUTHOR]

Brachypodium stacei is the most ancestral lineage in the genus Brachypodium, a model system for grass functional genomics. B. stacei shows striking and sometimes contradictory biological and evolutionary features, including a high selfing rate yet extensive admixture, an ancient Miocene origin yet with recent evolutionary radiation, and adaptation to different dry climate conditions in its narrow distribution range. Therefore, it constitutes an ideal system to study these life history traits. We studied the phylogeography of 17 native circum‐Mediterranean B. stacei populations (39 individuals) using genome‐wide RADseq SNP data and complete plastome sequences. Nuclear SNP data revealed the existence of six distinct genetic clusters, low levels of intra‐population genetic diversity and high selfing rates, albeit with signatures of admixture. Coalescence‐based dating analysis detected a recent split between crown lineages in the Late Quaternary. Plastome sequences showed incongruent evolutionary relationships with those recovered by the nuclear data, suggesting interbreeding and chloroplast capture events between genetically distant populations. Demographic and population dispersal coalescent models identified an ancestral origin of B. stacei in the western‐central Mediterranean islands, followed by an early colonization of the Canary Islands and two independent colonization events of the eastern Mediterranean region through long‐distance dispersal and bottleneck events as the most likely evolutionary history. Climate niche data identified three arid niches of B. stacei in the southern Mediterranean region. Our findings indicate that the phylogeography of B. stacei populations was shaped by recent radiations, frequent extinctions, long‐distance dispersal events, occasional interbreeding, and adaptation to local climates. [ABSTRACT FROM AUTHOR]

Scutellaria strigillosa Hemsl., known for its traditional use in Chinese herbal medicine, is valued for heat-clearing and detoxifying, promoting diuresis, reducing swelling, alleviating pain, and preventing miscarriage. Despite its historical use, comprehensive studies on pharmacophylogenetic analysis, including genetic and chemical profiles and the antimicrobial activity of S. strigillosa are still lacking. Understanding these aspects is crucial for fully realizing its therapeutic potential and ensuring sustainable use. This study aims to elucidate these aspects through comparative genomics, metabolomics, and antimicrobial assays with Scutellaria baicalensis Georgi and Scutellaria barbata D. Don. The chloroplast genome of S. strigillosa was assembled, measuring 152,533 bp, and revealing a high degree of conservation, especially in the protein-coding regions, and identified four regions trnK(UUU)-rps16, trnN(GUU)-trnR(ACG), accD-psaI, psbE-petL) of variability that could serve as phylogenetic markers. The phylogenetic analysis revealed a closer genetic relationship of S. strigillosa with S. tuberifera and S. scordifolia than traditionally classified, suggesting a need for taxonomic reevaluation within the genus. UPLC-Q-TOF-MS analysis in negative ion mode was used to explore the chemical diversity among these species, revealing distinct variations in their chemical compositions. S. strigillosa shared a closer chemical profile with S. barbata, aligning with phylogenetic findings. Metabolomic identification through Progenesis QI software resulted in the tentative identification of 112 metabolites, including a substantial number of flavonoids, diterpenoids, iridoid glycosides, phenylethanoid glycosides, and others. HPLC analysis further detailed the concentrations of 12 actives across the species, highlighting the variation in compound content. S. strigillosa shows antibacterial activity against Staphylococcus aureus and Pseudomonas aeruginosa, similar to S. baicalensis root extracts. This research enhances the understanding of the phylogenetic and phytochemical profiles and the antibacterial activity of S. strigillosa, offering new insights into its medicinal properties. The findings suggest a need for taxonomic reevaluation within the genus and underscore the potential antibacterial activity of S. strigillosa for therapeutic applications. Further studies are encouraged to explore its full medicinal potential and contribute to the sustainable development of Scutellaria species. [ABSTRACT FROM AUTHOR]

Understanding host-microbe interactions in planta is an expanding area of research. Amplicon sequencing of the 16S rRNA gene is a powerful and common method to study bacterial communities associated with plants. However, the co-amplification of mitochondrial and plastid 16S rRNA genes by universal primers impairs the sensitivity and performance of 16S rRNA sequencing. In 2020, a new method, Cas-16S-seq, was reported in the literature to remove host contamination for profiling the microbiota in rice, a well-studied domestic plant, by engineering RNA-programmable Cas9 nuclease in 16S rRNA sequencing. For the first time, we tested the efficiency and applicability of the Cas-16S-seq method on foliage, flowers, and seed of a non-domesticated wild plant for which there is limited genomic information, Leptospermum scoparium (mānuka). Our study demonstrated the efficiency of the Cas-16S-seq method for L. scoparium in removing host contamination in V4-16S amplicons. An increase of 46% in bacterial sequences was found using six guide RNAs (gRNAs), three gRNAs targeting the mitochondrial sequence, and three gRNAs targeting the chloroplast sequence of L. scoparium in the same reaction. An increase of 72% in bacterial sequences was obtained by targeting the mitochondrial and chloroplast sequences of L. scoparium in the same sample at two different steps of the library preparation (DNA and 1st step PCR). The number of OTUs (operational taxonomic units) retrieved from soil samples was consistent when using the different methods (Cas-16S-seq and 16S-seq) indicating that the Cas-16S-seq implemented for L. scoparium did not introduce bias to microbiota profiling. Our findings provide a valuable tool for future studies investigating the bacterial microbiota of L. scoparium in addition to evaluating an important tool in the plant microbiota research on other non-domesticated wild species. [ABSTRACT FROM AUTHOR]

Introduction: This study presents the first complete plastome (cpDNA) sequence of Psydrax latifolia, a member of the Rubiaceae family, which includes small trees, smooth shrubs, and occasionally lianas. This specimen was collected near the Red Sea coast in Jazan province, Saudi Arabia, specifically in the paleotropical Fifa Mountains. The research aimed to characterize and compare the plastome of Psydrax latifolia with other species in the Rubiaceae family to enhance our understanding of its evolutionary dynamics and phylogenetic relationships. Methods: The plastome of P. latifolia was sequenced and reconstructed using whole-genome next-generation sequencing (NGS) techniques. Comparative analyses were performed between the plastome of P. latifolia and 16 other species within the Rubiaceae family to identify genomic features and evolutionary patterns. The plastome structure, gene content, and codon usage were analyzed, with a focus on the Relative Synonymous Codon Usage (RSCU) in different regions of the plastome. Results: The plastome of P. latifolia was found to be 153,242 base pairs (bp) in length, including a large single copy (LSC) region of 83,603 bp, a small single copy (SSC) region of 18,115 bp, and a pair of inverted repeats (IRs) of 25,762 bp each. It contained 87 protein-coding genes, 8 rRNA genes, and 33 tRNA genes, with an overall GC content of 37.30%. The RSCU analysis revealed regional variation, with the protein-coding region being more conserved than the intergenic spacer. Discussion: This study provides the first complete plastome sequence of Psydrax latifolia, offering insights into its genomic structure and phylogenetic position within the Rubiaceae family. Comparative analyses with 16 Rubiaceae species highlighted distinct genomic features and evolutionary patterns. These findings contribute to the understanding of plastome evolution in the Rubiaceae family and provide a valuable resource for future phylogenetic and evolutionary studies. [ABSTRACT FROM AUTHOR]

The Halimedineae are marine green macroalgae that play crucial roles as primary producers in various habitats, including coral reefs, rocky shores, embayments, lagoons, and seagrass beds. Several tropical species have calcified thalli, which contribute significantly to the formation of coral reefs. In this study, we investigated the codon usage patterns and the main factors influencing codon usage bias in 16 chloroplast genomes of the suborder Halimedineae. Nucleotide composition analysis revealed that the codons of these species were enriched in A/U bases and preferred to end in A/U bases, and the distribution of GC content followed a trend of GC1 > GC2 > GC3. 30 optimal codons encoding 17 amino acids were identified, and most of the optimal codons and all of the over-expressed codons preferentially ended with A/U. The neutrality plot, effective number of codons (ENc) plot, and parity rule 2 (PR2) plot analysis indicated that natural selection played a major role in shaping codon usage bias of the most Halimedineae species. The genetic relationships based on their RSCU values and chloroplast protein-coding genes showed the closely related species have similar codon usage patterns. This study describes, for the first time, the codon usage patterns and characterization of Halimedineae chloroplast genomes, and provides new insights into the evolution of this suborder. [ABSTRACT FROM AUTHOR]

The succulent shrubs Desmidorchis penicillata and D. retrospiciens, part of the taxonomically challenging genus Desmidorchis, are well‐known for their ecological resilience and medicinal significance. This study sequences the first complete chloroplast genomes of these species, shedding light on their genomic characteristics and evolutionary relationships. The circular genomes of D. penicillata (161 776 bp) and D. retrospiciens (162 277 bp) display a quadripartite structure typical of Angiosperms. Gene content, order, and GC content are consistent, featuring 114 unique genes, including 80 protein‐coding, 30 transfer RNAs, and four ribosomal RNAs genes. Codon usage analysis underscores A/U‐rich preferences, while RNA editing sites, predominantly in ndhB and ndhD genes, suggest post‐transcriptional modifications. Analysis of long repeated sequences reveals a predominance of forward and palindromic repeats. Simple sequence repeats (SSRs), particularly A/T motifs, are abundant, with high presence of mononucleotide, offering potential molecular markers. Comparative analysis with their relatives in subtribe Stapeliinae identifies mutational hotspots such as ycf1, ndhF, trnG(GCC)‐trnfM(CGA) and ndhG‐ndhI that could be potential DNA barcoding markers. The inverted repeat (IR) boundaries analysis revealed an expansion of IR on the small single copy region, leading to the formation of a pseudogene. Overall, substitution rate analysis indicated purifying selection, with a few genes (rpl22, clpP and rps11) showing signatures of positive selection. Additionally, the phylogenetic analysis positioned Desmidorchis within the Stapeliinae clade and strongly supported the sister relationship between D. penicillata and D. retrospiciens. This study provides comprehensive molecular data for future research in Desmidorchis. [ABSTRACT FROM AUTHOR]

Flowering plant (angiosperm) mitochondrial genomes are remarkably dynamic in their structures. We present the complete mitochondrial genome of hawthorn (Crataegus pinnatifida Bunge), a shrub that bears fruit and is celebrated for its extensive medicinal history. We successfully assembled the hawthorn mitogenome utilizing the PacBio long-read sequencing technique, which yielded 799,862 reads, and the Illumina novaseq6000 sequencing platform, which producing 6.6 million raw paired reads. The C. pinnatifida mitochondria sequences encompassed a total length of 440,295 bp with a GC content of 45.42%. The genome annotates 54 genes, including 34 that encode proteins, 17 that encode tRNA, and three genes for rRNA. A fascinating interplay was observed between the chloroplast and mitochondrial genomes, which share 17 homologous sequences sequences that rotal 1,933 bp. A total of 134 SSRs, 22 tandem repeats and 42 dispersed repeats were identified in the mitogenome. Four conformations of C. pinnatifida mitochondria sequences recombination were verified through PCR experiments and Sanger sequencing, and C. pinnatifida mitogenome is more likely to be assembled into three circular-mapping chromosomes. All the RNA editing sites that were identified C-U edits, which predominantly occurred at the first and second positions of the codons. Phylogenetic and collinearity analyses identified the evolutionary trajectory of C. pinnatifida, which reinforced the genetic identity of the hawthorn section. This unveiling of the unique multi-partite structure of the hawthorn mitogenome offers a foundational reference for future study into the evolution and genetics of C. pinnatifida. [ABSTRACT FROM AUTHOR]

Polygonati Rhizoma and Polygonati odorati Rhizoma, known as "Huangjing" and "Yuzhu" in China, are medicinal Polygonatum species resources with top-grade medical and edible properties. The chloroplast (cp) genome has been used to study species diversity, evolution, and breeding of species for applications in genetic engineering. Codon usage bias (CUB), a common and complex natural phenomenon, is essential for studies of codon optimization of exogenous genes, genetic engineering, and molecular evolution. However, the CUB of medicinal Polygonatum species chloroplast genomes has not been systematically studied. In our study, a detailed analysis of CUB was performed in the medicinal Polygonatum species chloroplast genomes. We investigated the codon bias of 204 plastid protein-coding genes (PCGs) in 4 medicinal Polygonatum species using CodonW and CUSP online software. Through the analysis of the codon bias index, we found that the medicinal Polygonatum species chloroplast genomes had weak codon usage bias. In addition, our results also showed a high preference for AT bases in medicinal Polygonatum species chloroplast genomes, and the preference to use AT-ending codons was observed in these species chloroplast genomes. The neutrality plot, ENC plot, PR2-Bias plot, and correspondence analysis showed that compared with mutation pressure, natural selection was the most important factor of CUB. Based on the comparative analysis of high-frequency codons and high expression codons, we also determined the 10-11 optimal codons of investigative medicinal Polygonatum species. Furthermore, the result of RSCU-based cluster analysis showed that the genetic relationship between different medicinal Polygonatum species could be well reflected. This study provided an essential understanding of CUB and evolution in the medicinal Polygonatum species chloroplast genomes. [ABSTRACT FROM AUTHOR]

Tamaricaceae comprises about 120 species and has a long evolutionary history, Tamarix Linn accounts for approximately 75% of the total species in this family. It is the most widely distributed and diverse genus in the family. They have important ecological significance for transforming deserts and improving climate conditions. However, Tamarix is the most poorly classified genera among flowering plants owing to its large variability and high susceptibility to interspecific hybridization. In this study, the complete chloroplast genomes of three Tamarix species and one draft chloroplast genome were obtained in this study. Combined with eight chloroplast genomes deposited in GenBank, complete chloroplast sequences of 12 Tamarix species were used for further analysis. There are 176 non‐SSR‐related indels and 681 non‐indel‐related SSRs in the 12 Tamarix chloroplast genomes. The mononucleotide SSRs are the most prevalent among all types of SSRs. The mVISTA results indicate high sequence similarities across the chloroplast genome, suggesting that the chloroplast genomes are highly conserved, except for sample Tamarix androssowii (ENC850343). The IR regions and the coding regions are more conserved than the single‐copy and noncoding regions. The trnF‐ndhJ, ndhC‐trnM‐CAU, ycf1, and trnL‐UAG‐ndhF regions are the most variable and have higher variability than those of the universal DNA markers. Finally, the first phylogenetic tree of Tamaricaceae was constructed which confirmed the monophyly of Tamarix in Tamaricaceae. The first phylogenetic tree of Tamarix was based on the complete chloroplast genome to date, the changes in branch length and support rate can potentially help us clarify the phylogenetic relationships of Tamarix. All the obtained genetic resources will facilitate future studies in population genetics, species identification, and conservation biology of Tamarix. [ABSTRACT FROM AUTHOR]

Glacial periods have been considered as inhospitable environments that consist of treeless vegetation at higher latitudes. The fossil record suggests many species survived the Last Glacial Maximum within refugia, usually at lower latitudes. However, phylogeographic studies have given support to the existence of previously unknown high-latitude refugia that were not detected in the fossil record. Here, we test the hypothesis that cold-tolerant trees of Patagonia survived cold periods in microclimatically favourable locales where hybridization occurred between sister taxa. To study local presence through glacial periods in multiple refugia, we used pollen records and genetic information (isozymes, microsatellites, and combined nuclear and chloroplast DNA sequences) of population pairs of Nothofagus antarctica and N. pumilio that belong to the ancient subgenus Nothofagus which can potentially hybridize in nature, along their entire latitudinal range in Patagonia. Studied species share the N. dombeyi type pollen, which was abundant at >20% in the northernmost latitudinal bands (35–43°S), even during the Last Glacial Maximum. Mid- and southern latitudinal records (44–55°S) yielded lower abundances of ~10% that increased after c. 15.0 cal. ka BP. Therefore, fossil pollen evidence suggests a long-lasting local presence of Nothofagus throughout glacial–interglacial cycles but mostly as small populations between 44°S and 51°S. We found species-specific and shared genetic variants, the latter of which attained relatively high frequencies, thus providing evidence of ancestral polymorphisms. Populations of each species were similarly diverse, suggesting survival throughout the latitudinal range. Estimates of coalescent divergence times were broadly synchronous across latitudes, suggesting that regional climates similarly affected populations and species that hybridized through climate cycles, fostering local persistence. Graphical Abstract [ABSTRACT FROM AUTHOR]

Premise: Molecular studies based on chloroplast markers have questioned the monophyly of the fern genus Pecluma (Polypodioideae, Polypodiaceae), which has several species of Polypodium nested within it. We explored the delimitation of Pecluma and its biogeographic pattern by evaluating the phylogenetic position of four Polypodium species not sequenced thus far and integrating the first fossil evidence of Pecluma. Methods: Using herbarium material, we applied a genome‐skimming approach to obtain a phylogenetic hypothesis of Polypodioideae; assessed the combination of character states observed in the fossil from Miocene Dominican amber using a previously published phylogeny of Polypodioideae based on four plastid markers as framework; calculated divergence times; and conducted an ancestral area estimation. Results: Within Polypodioideae, Pecluma was recovered as sister to Phlebodium. Three of the newly sequenced species—Polypodium otites, P. pinnatissimum, and P. ursipes—were recovered with maximum support within the Pecluma clade, whereas P. christensenii remained within Polypodium. The closest combination of character states of the fossil was found within Pecluma. Our biogeographic analyses suggest an Eocene origin of the genus in South America, with several subsequent Oligocene and Miocene colonization events to Mexico–Central America and to the West Indies. Conclusions: Although the circumscription of Pecluma is still challenging, our results elucidate the origin and age of the genus. The newly described fossil, Pecluma hispaniolae sp. nov., supports the hypothesis that the epiphytic communities of the Greater Antilles exhibit a constant generic composition since the Miocene. We propose new combinations (Pecluma otites, Pecluma pinnatissima, and Pecluma ursipes) to accommodate three species previously classified in Polypodium. [ABSTRACT FROM AUTHOR]

Premise: The wheat tribe, Triticeae, has been the subject of molecular phylogenetic analyses for nearly three decades, and extensive phylogenetic conflict has been apparent from the earliest comparisons among DNA‐based data sets. While most previous analyses focused primarily on nuclear vs. chloroplast DNA conflict, the present analysis provides a broader picture of conflict among nuclear loci throughout the tribe. Methods: Exon data were generated from over 1000 nuclear loci using targeted sequence capture with custom baits, and nearly complete chloroplast genome sequences were recovered. Phylogenetic conflict was assessed among the trees from the chloroplast genomes, the concatenated nuclear loci, and a series of nuclear‐locus subsets guided by Hordeum chromosome gene maps. Results: At the intergeneric level, the analyses collectively revealed a few broadly consistent relationships. However, the prevailing pattern was one of extensive phylogenetic conflict throughout the tribe, among both deep and shallow branches, and with the extent of the conflict varying among data subsets. Conclusions: The results suggest continual introgression or lineage sorting within and among the named lineages of the Triticeae, shaping both deep and shallow relationships in the tribe. [ABSTRACT FROM AUTHOR]

Codon usage bias refers to the preferential use of synonymous codons, a widespread phenomenon found in bacteria, plants, and animals. Codon bias varies among species, families, and groups within kingdoms and between genes within an organism. Codon usage bias (CUB) analysis sheds light on the evolutionary dynamics of various species and optimizes targeted gene expression in heterologous host plants. As a significant order of gymnosperms, species within Gnetales possess extremely high ecological and pharmaceutical values. However, comprehensive analyses of CUB within the chloroplast genomes of Gnetales species remain unexplored. A systematic analysis was conducted to elucidate the codon usage patterns in 13 diverse Gnetales species based on the chloroplast genomes. Our results revealed that chloroplast coding sequences (cp CDSs) in 13 Gnetales species display a marked preference for AT bases and A/T-ending codons. A total of 20 predominantly high-frequency codons and between 2 and 7 optimal codons were identified across these species. The findings from the ENC-plot, PR2-plot, and neutrality analyses suggested that both mutation pressure and natural selection exert influence on the codon bias in these 13 Gnetales species, with natural selection emerging as the predominant influence. Correspondence analysis (COA) demonstrated variation in the codon usage patterns among the Gnetales species and indicated mutation pressure is another factor that could impact CUB. Additionally, our research identified a positive correlation between the measure of idiosyncratic codon usage level of conservatism (MILC) and synonymous codon usage order (SCUO) values, indicative of CUB's potential influence on gene expression. The comparative analysis concerning codon usage frequencies among the 13 Gnetales species and 4 model organisms revealed that Saccharomyces cerevisiae and Nicotiana tabacum were the optimal exogenous expression hosts. Furthermore, the cluster and phylogenetic analyses illustrated distinct patterns of differentiation, implying that codons, even with weak or neutral preferences, could affect the evolutionary trajectories of these species. Our results reveal the characteristics of codon usage patterns and contribute to an enhanced comprehension of evolutionary mechanisms in Gnetales species. [ABSTRACT FROM AUTHOR]

Begonia pedatifida has persistently been utilized as a traditional folk herbal medicine. This study has sequenced the chloroplast genome of B. pedatifida to establish its genomic characteristics and to discern its phylogenetic relationships with other closely related species. The chloroplast genome structure of B. pedatifida reveals a circular molecule with a length of 169,606 bp, including a large single copy (LSC) region of 76,086 bp, a small single copy (SSC) region of 18,314 bp, and a pair of inverted repeats (IRS) region of 37,603 bp. The entire genome contains 138 genes, which consist of 88 protein-coding genes, 42 tRNA genes, and 8 rRNA genes. Phylogenetic analysis suggests that B. pedatifida is closely related to Begonia emeiensis, Begonia jinyunensis, and Begonia pulchrifolia, sharing a common ancestor and forming sister lineages. This research provides genetic information for further study on B. pedatifida. [ABSTRACT FROM AUTHOR]

Erodium cicutarium is an annual herbaceous plant valued for its applications in traditional medicine. However, the chloroplast genome of E. cicutarium has yet to be reported. In this study, we assembled chloroplast genomes of Erodium cicutarium using Illumina sequencing reads. The chloroplast genome was 114,652 bp long, harbored 111 complete genes, and its overall GC content was 39.1%. In Maximum Likelihood (ML) and Bayesian inference (BI) trees, the 13 Erodium species divided into three main clades, with E. cicutarium and E. carvifolium forming a monophyletic group, suggesting a close relationship between the two species. The E. cicutarium cp genome presented in this study lays a good foundation for the Erodium. [ABSTRACT FROM AUTHOR]

Primula medogensis W.B Ju, B. Xu & X.F. Gao 2023, a new species categorized under P. sect. Cordifoliae, was officially described in 2023. Given its recent classification, the genetic resources for this species are currently very limited. Here, we sequenced and assembled the first complete chloroplast genome of P. medogensis using Illumina sequencing technology. The complete chloroplast genome of P. medogensis is 151,486 bp in length, exhibiting a typical quadripartite structure. It consists of a large single-copy region (LSC; 83,407 bp) and a small single-copy region (SSC;17675 bp), separated by a pair of inverted repeat regions (IRs; 25202 bp). A total of 131 genes were annotated, including 86 protein-coding, 37 tRNA, and eight rRNA genes. The overall GC content was 37.1%. Phylogenetic analysis of 59 Primula species revealed a close relationship between P. medogensis and P. calliantha subsp. bryophila. [ABSTRACT FROM AUTHOR]

Liparis gigantea is a Chinese traditional medicinal herb in the Orchidaceae family. It is a rare and special Liparis species that exhibits relatively large flowers. To illuminate its phylogenetic status and augment genomic resources, the complete chloroplast (cp) genome of L. gigantea was first sequenced and assembled using whole genome next-generation sequencing in this study. The cp genome size is 158,462 bp with a total GC content of 36.9%. Characterized by a quadripartite structure, the genome consists of a large single-copy (LSC) region of 86,032 bp, a small single-copy (SSC) region of 18,322 bp, which is separated by a pair of 27,054 bp inverted repeat regions (IRs). A total of 133 genes were annotated, including 87 protein-coding genes, 38 tRNA genes, and 8 rRNA genes. Phylogenetic analysis strongly supported L. gigantea as the sister to two closely related terrestrial species, Liparis nervosa and L. vivipara. The results of this study provide genomic information for future research and application of this medicinal herb. [ABSTRACT FROM AUTHOR]

Arytera littoralis Blume 1847 is an evergreen small tree belonging to the Sapindaceae family. It is distributed in South China to SE Asia and the Solomon Islands. However, the chloroplast genome of A. littoralis has yet to be reported. In this study, the complete chloroplast genome of Arytera littoralis was determined. The total genome size was 161,091 bp in length, consisting of two inverted repeats (IRs) (28,432 bp) separated by the large single-copy (LSC) (85,737 bp) and small single-copy (SSC) (18,490 bp) regions. The genome contained 133 genes, including 87 protein-coding genes, 37 tRNA genes, and eight rRNA genes. The GC content of the complete chloroplast genome was 37.8%. A maximum-likelihood (ML) phylogenetic tree of A. littoralis and 13 related species from the family Sapindaceae indicated that A. littoralis was close to a clade composed of Sapindus, Nephelium, Litchi, and Dimocarpus. This study will offer essential genetic resources of A. littoralis and provide insights into the phylogeny and evolution of Sapindaceae. [ABSTRACT FROM AUTHOR]

Artemisia sylvatica Maximowicz 1859 is one of the medicinal herbs in Artemisia. This study presents the complete chloroplast genome of A. sylvatica, sequenced using the Illumina NovaSeq platform. The genome is 151,161 bp in length, featuring a GC content of 38%. It consists of a large single-copy (LSC) region of 82,892 bp, a small single-copy (SSC) region of 18,353 bp, and two inverted repeat (IR) regions of 24,958 bp each. In total, the genome contains 132 genes, including 87 protein-coding genes, 37 tRNA genes, and 8 rRNA genes. Phylogenetic analysis positions A. sylvatica within the subgenus Artemisia, highlighting its evolutionary relationships within this diverse genus. The first chloroplast genome of A. sylvatica was reported in this work contributes to the enrichment of genomic data for the genus Artemisia. [ABSTRACT FROM AUTHOR]

Garcinia esculenta Y. H. Li. 1981 (Clusiaceae) is an endemic tree species in China, primarily found in western and northwestern Yunnan Province. In this research, the complete chloroplast genome of G. esculenta was sequenced using the Illumina NovaSeq6000 platform. The result showed that the length of the complete chloroplast genome was 155,853 bp, which was composed of a large single-copy region (LSC) of 84,534 bp, a small single-copy region (SSC) of 17,175 bp, and a pair of inverted repeat (IR) regions of 27,072 bp. The overall GC content was 36.1%. The complete chloroplast genome encompassed 128 genes, comprising 83 protein-coding genes, 37 tRNA genes, and 8 rRNA genes. Phylogenetic analysis of the complete chloroplast genome sequences of 22 species revealed that G. esculenta is most closely related to G. oblongifolia. [ABSTRACT FROM AUTHOR]

Baeckea frutescens Linaeus 1753, as a traditional folk medicine in South East Asia, possesses sesquiterpenes, phloroglucinols, chromones, and essential oil, and is utilized for traditional Chinese medicinal purposes. The genetic diversity of the plant must be better understood, considering its significance. The complete chloroplast (cp) genome of B. frutescens was sequenced and assembled by using Illumina paired-end data, marking a significant advancement toward comprehending its genetic composition. The complete cp genome is 158,939 bp in length and contains 128 genes, consisting of 83 protein-coding genes, 8 ribosomal RNA genes, and 37 transfer RNA genes. Phylogenetic analyses indicated that B. frutescens and other the 13 were clustered to the family of Myrtaceae. These findings are crucial for the conservation and utilization of this important plant species. Additionally, they underscore the potential for future research on the evolution and preservation of B. frutescens, which could be advantageous in pharmaceutical applications. [ABSTRACT FROM AUTHOR]

Tabebuia rosea is a world-renowned woody plant with colorful flowers in full bloom. In addition to its high ornamental value, it also has ecological and medicinal value. In this study, the complete circular chloroplast genome of T. rosea was reconstructed and annotated using Illumina sequencing. The chloroplast genome was 158,919 bp in size with GC content of 38.21%, including a large single-copy region of 85,823 bp, a small single-copy region of 12,816 bp, and a pair of inverted repeats of 30,140 bp. It encoded 132 genes, including 87 protein-coding genes, 37 tRNA genes, and 8 rRNA genes. Based on current available chloroplast genome sequences, the phylogenetic analysis indicated that T. rosea was clustered with T. nodosa and H. chrysanthus. This study provided insights into the evolutionary relationships among different species of Bignoniaceae. [ABSTRACT FROM AUTHOR]

The genus Calyptothecium, currently comprising ca. 30 species worldwide, is the largest genus within the family Pterobryaceae. However, a comprehensive taxonomic revision of this genus is lacking. Calyptothecium philippinense Broth. 1899, a moss species widely found in the tropical regions of Asia, is characterized by the unique rugose leaves and large auriculate leaf bases. In this study, we sequenced the complete chloroplast genome (CPG) of C. philippinense using the Illumina NovaSeq 6000 platform. The length of the CPG of C. philippinense was determined to be 124,513 bp, with an AT content of 74%. The CPG of C. philippinense exhibited a standard quadripartite structure, consisting of one small single-copy (SSC) region (18,541 bp), one large single-copy region (LSC) (87,222 bp), and two inverted repeat (IR) regions (9375 bp each). A total of 126 genes from the CPG of C. philippinense were annotated, including 82 protein-coding genes, eight ribosomal RNA genes, and 36 transfer RNA genes. Phylogenetic analysis based on the CPGs of 25 bryophyte taxa revealed that the three Pterobryaceae species C. philippinense, Calyptothecium hookeri (Mitt.) Broth. and Pterobryopsis orientalis (Müll. Hal.) M. Fleisch. formed a robust clade. The findings could facilitate more accurate classification and help elucidate evolutionary relationships within Calyptothecium. [ABSTRACT FROM AUTHOR]