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Firmiana major is an endangered species in southwest China, which had been considered as extinct in the wild on the IUCN Red List of Threatened Species in 1998. Fortunately, around 2000 wild individuals were rediscovered along the valley of Jinshajiang river in south Sichuan and north Yunnan. In this study, we reported a complete chloroplast genome of F. major, which was de novo assembled using the next-generation sequencing data. The plastome was 161,302 bp in length, consisting of a pair of inverted repeat (25,543 bp for each), one large single copy (90,178 bp) and one small single copy (20,038 bp) regions. The whole genome contained 132 genes, including 87 protein-coding, 37 tRNA and 8 rRNA genes. The overall GC content of the whole genome was 36.9%. Maximum likelihood analysis showed that F. major was sister to Tilia spp. [ABSTRACT FROM AUTHOR]

During a study of saprobic fungi from Bagno di Cetica Province, Italy, we collected a pleosporoid ascomycete on stems of Cytisus sp. In morphology, our collection is similar to Cucurbitaria species, but molecular analysis of SSU, LSU and ITS genes reveals it can be referred to Camarosporium . In this study we compare all other Cucurbitaria species from Cytisus sp. and based on both morphology and molecular data, we introduce our collection as a new species in Camarosporium viz . C. arezzoensis . [ABSTRACT FROM AUTHOR]

The order Asterinales comprises a single family, Asterinaceae. In this study, types or specimens of 41 genera of Asterinaceae are re-examined and re-described and illustrated by micrographs. Seventeen genera, namely Asterina (type genus), Asterinella, Asterotexis, Batistinula, Cirsosia, Echidnodella, Halbania, Lembosia, Meliolaster, Parasterinopsis, Platypeltella, Prillieuxina, Schenckiella (= Allothyrium), Trichasterina, Trichopeltospora, Uleothyrium and Vizellopsis, are maintained within Asterinaceae. Echidnodes, Lembosiella, Lembosina, Morenoina, and Thyriopsis are transferred to Aulographaceae based on morphological and molecular characteristics. Anariste is transferred to Micropeltidaceae, while Lembosiopsis is transferred to Mycosphaerellaceae. Placoasterella and Placosoma are morphologically close to taxa in Parmulariaceae, where they are transferred. Aulographina is placed in Teratosphaeriaceae, while Asterodothis, Asterinema, Dothidasteromella, Leveillella, Petrakina and Stephanotheca are transferred to Dothideomycetes, genera incertae sedis. Eupelte, Macowaniella, Maheshwaramyces, Parasterinella, and Vishnumyces are treated as doubtful genera, because of lack of morphological and molecular data. Aphanopeltis, Asterolibertia, Neostomella, Placoasterina, and Symphaster are synonyms of Asterina based on morphology, while Trichamelia, Viegasia, and Yamamotoa are synonyms of Lembosia. The characteristics of each family are discussed and a phylogenetic tree is included. [ABSTRACT FROM AUTHOR]

DNA barcoding is a technique to identify species by using standardized DNA sequences. In this study, a total of 105 samples, representing 30 Parnassia species, were collected to test the effectiveness of four proposed DNA barcodes ( rbcL, matK, trnH -psbA and ITS) for species identification. Our results demonstrated that all four candidate DNA markers have a maximum level of primer universality and sequencing success. As a single DNA marker, the ITS region provided the highest species resolution with 86.7%, followed by trnH -psbA with 73.3%. The combination of the core barcode regions, matK+ rbcL, gave the lowest species identification success (63.3%) among any combination of multiple markers and was found unsuitable as DNA barcode for Parnassia. The combination of ITS+ trnH -psbA achieved the highest species discrimination with 90.0% resolution (27 of 30 sampled species), equal to the four-marker combination and higher than any two or three marker combination including rbcL or matK. Therefore, matK and rbcL should not be used as DNA barcodes for the species identification of Parnassia. Based on the overall performance, the combination of ITS+ trnH -psbA is proposed as the most suitable DNA barcode for identifying Parnassia species. DNA barcoding is a useful technique and provides a reliable and effective mean for the discrimination of Parnassia species, and in combination with morphology-based taxonomy, will be a robust approach for tackling taxonomically complex groups. In the light of our findings, we found among the three species not identified a possible cryptic speciation event in Parnassia. [ABSTRACT FROM AUTHOR]

The generic limits in the Pyrenaria complex are discussed based on morphological and molecular evidence. The phylogeny of the Pyrenaria complex was reconstructed using parsimony and Bayesian analyses of sequence data from the nuclear internal transcribed spacer (ITS) region. The Pyrenaria complex is shown to be monophyletic and is sister to the Camellia- Polyspora clade. None of the previously recognized genera (including Pyrenaria, Tutcheria, Parapyrenaria and Sinopyrenaria) is monophyletic, and the species of these genera are scattered and nested within the Pyrenaria complex, suggesting that the four genera should be combined as Pyrenaria sensu lato. This study indicates a close relationship among the genera within the Pyrenaria complex, Camellia and Polyspora, and reveals that Camellia has a closer relationship with Polyspora than with the Pyrenaria complex. [ABSTRACT FROM AUTHOR]

The millions of herbarium specimens in collections around the world provide historical resources for phylogenomics and evolutionary studies. Many rare and endangered species exist only as historical specimens. Here, we report a case study of the monotypic Pseudobartsia yunnanensis D. Y. Hong (=Pseudobartsia glandulosa[Bentham] W. B. Yu & D. Z. Li: Orobanchaceae) known from a single Chinese collection taken in 1940. We obtained genomic data of Pseudobartsia glandulosa using high‐throughput short‐read sequencing, and then assembled a complete chloroplast genome and nuclear ribosome DNA region in this study. We found that the newly assembled three plastid DNA regions (atpB‐rbcL, rpl16, and trnS‐G) and nuclear ribosomal internal transcribed spacer (nrITS) of Pseudobartsia glandulosa were more than 99.98% similar to published sequences obtained by target sequencing. Phylogenies of Orobanchaceae using 30 plastomes (including 10 new plastomes), using both supermatrix and multispecies coalescent approaches following a novel plastid phylogenomic workflow, recovered seven recognized tribes and two unranked groups, both of which were proposed as new tribes, that is, Brandisieae and Pterygielleae. Within Pterygielleae, all analyses strongly supported Xizangia D. Y. Hong as the first diverging genus, with Pseudobartsia D. Y. Hong as sister to Pterygiella Oliver + Phtheirospermum Bunge (excluding Phtheirospermum japonicum [Thunberg] Kanitz); this supports reinstatement of Pseudobartsia and Xizangia. Although elements of Buchnereae‐Cymbarieae‐Orobancheae and Brandisieae‐Pterygielleae‐Rhinantheae showed incongruence among gene trees, the topology of the supermatrix tree was congruent with the majority of gene trees and functional‐group trees. Therefore, most plastid genes are evolving as a linkage group, allowing the supermatrix tree approach to yield internally consistent phylogenies for Orobanchaceae. [ABSTRACT FROM AUTHOR]

Dalbergia odorifera T. C. Chen (Leguminosae), a rare and endangered tree species endemic to Hainan Island of China, produces the most expensive and rarest wood in China. The wood characteristics of D. odorifera are remarkably similar to those of D. tonkinensis (a much less sought‐after species from Vietnam), and the DNA from wood is often highly degraded, making it very difficult to identify the two species using anatomical features or DNA barcoding based on regular DNA markers. To solve the confusion of identifying wood reliably from the two species, we built and analyzed the plastome library of 26 samples from 18 Dalbergia species, of which 12 samples from eight closely related species of D. odorifera are newly sequenced in this study. Phylogenomic analysis suggested that the relationships among the 26 samples are mostly well resolved, and conspecific individuals from different populations of D. odorifera and D. tonkinensis clustered together. Between the plastid genomes of the two species, we identified 129 indels and 114 single nucleotide polymorphisms. By assessing a subset of 20 nucleotide polymorphisms and 10 indels using 37 population‐level samples (20 samples of D. odorifera and 17 samples of D. tonkinensis), we recovered eight species‐specific barcode regions that could be suitable for identifying the wood D. odorifera and D. tonkinensis. To examine their utility in wood identification, we amplified the eight DNA barcodes using six wood samples and recovered an amplification success rate of 83.3%, demonstrating a reliable method for precise wood identification of the two species. [ABSTRACT FROM AUTHOR]

Background: Paris (Melanthiaceae) is an economically important but taxonomically difficult genus, which is unique in angiosperms because some species have extremely large nuclear genomes. Phylogenetic relationships within Paris have long been controversial. Based on complete plastomes and nuclear ribosomal DNA (nrDNA) sequences, this study aims to reconstruct a robust phylogenetic tree and explore historical biogeography and clade diversification in the genus. Results: All 29 species currently recognized in Paris were sampled. Whole plastomes and nrDNA sequences were generated by the genome skimming approach. Phylogenetic relationships were reconstructed using the maximum likelihood and Bayesian inference methods. Based on the phylogenetic framework and molecular dating, biogeographic scenarios and historical diversification of Paris were explored. Significant conflicts between plastid and nuclear datasets were identified, and the plastome tree is highly congruent with past interpretations of the morphology. Ancestral area reconstruction indicated that Paris may have originated in northeastern Asia and northern China, and has experienced multiple dispersal and vicariance events during its diversification. The rate of clade diversification has sharply accelerated since the Miocene/Pliocene boundary. Conclusions: Our results provide important insights for clarifying some of the long-standing taxonomic debates in Paris. Cytonuclear discordance may have been caused by ancient and recent hybridizations in the genus. The climatic and geological changes since the late Miocene, such as the intensification of Asian monsoon and the rapid uplift of Qinghai-Tibet Plateau, as well as the climatic fluctuations during the Pleistocene, played essential roles in driving range expansion and radiative diversification in Paris. Our findings challenge the theoretical prediction that large genome sizes may limit speciation. [ABSTRACT FROM AUTHOR]

Background: The genus Ilex (Aquifoliaceae) has a near-cosmopolitan distribution in mesic habitats from tropical to temperate lowlands and in alpine forests. It has a high rate of hybridization and plastid capture, and comprises four geographically structured plastid groups. A previous study showed that the plastid rbcL gene, coding for the large subunit of Rubisco, has a particularly high rate of non-synonymous substitutions in Ilex, when compared with other plant lineages. This suggests a strong positive selection on rbcL, involved in yet unknown adaptations. We therefore investigated positive selection on rbcL in 240 Ilex sequences from across the global range. Results: The rbcL gene shows a much higher rate of positive selection in Ilex than in any other plant lineage studied so far (> 3000 species) by tests in both PAML and SLR. Most positively selected residues are on the surface of the folded large subunit, suggesting interaction with other subunits and associated chaperones, and coevolution between positively selected residues is prevalent, indicating compensatory mutations to recover molecular stability. Coevolution between positively selected sites to restore global stability is common. Conclusions: This study has confirmed the predicted high incidence of positively selected residues in rbcL in Ilex, and shown that this is higher than in any other plant lineage studied so far. The causes and consequences of this high incidence are unclear, but it is probably associated with the similarly high incidence of hybridization and introgression in Ilex, even between distantly related lineages, resulting in large cytonuclear discordance in the phylogenies. [ABSTRACT FROM AUTHOR]

The genus Amomum includes over 111 species, 6 of which are widely utilized as medicinal plants and have already undergone taxonomic revision. Due to their morphological similarities, the presence of counterfeit and substandard products remains a challenge. Accurate plant identification is, therefore, essential to address these issues. This study utilized 11 newly sequenced samples and extensive NCBI data to perform molecular identification of the six medicinal "Doukou" species. The plastomes of these species exhibited a typical quadripartite structure with a conserved gene content. However, independent variation shifts of the SC/IR boundaries existed between and within species. The comprehensive set of genetic sequences, including ITS, ITS1, ITS2, complete plastomes, matK, rbcL, psbA-trnH, and ycf1, showed varying discrimination of the six "Doukou" species based on both distance and phylogenetic tree methods. Among these, the ITS, ITS1, and complete plastome sequences demonstrated the highest identification success rate (3/6), followed by ycf1 (2/6), and then ITS2, matK, and psbA-trnH (1/6). In contrast, rbcL failed to identify any species. This research established a basis for a reliable molecular identification method for medicinal "Doukou" plants to protect wild plant resources, promote the sustainable use of medicinal plants, and restrict the exploitation of these resources. [ABSTRACT FROM AUTHOR]

Background: The world's herbaria contain millions of specimens, collected and named by thousands of researchers, over hundreds of years. However, this treasure has remained largely inaccessible to genetic studies, because of both generally limited success of DNA extraction and the challenges associated with PCR-amplifying highly degraded DNA. In today's next-generation sequencing world, opportunities and prospects for historical DNA have changed dramatically, as most NGS methods are actually designed for taking short fragmented DNA molecules as templates. Results: As a practical test of routine recovery of rDNA and plastid genome sequences from herbarium specimens, we sequenced 25 herbarium specimens up to 80 years old from 16 different Angiosperm families. Paired-end reads were generated, yielding successful plastid genome assemblies for 23 species and nuclear rDNAs for 24 species, respectively. These data showed that genome skimming can be used to generate genomic information from herbarium specimens as old as 80 years and using as little as 500 pg of degraded starting DNA. Conclusions: The routine plastome sequencing from herbarium specimens is feasible and cost-effective (compare with Sanger sequencing or plastome-enrichment approaches), and can be performed with limited sample destruction. [ABSTRACT FROM AUTHOR]

Summary: Synonymous substitution rates in plant mitochondrial genomes vary by orders of magnitude among species, whereas synonymous rates among genes within a genome are generally consistent. Exceptionally, genes within the Ajuga reptans (Lamiaceae) mitochondrial genome exhibit unprecedented intragenomic heterogeneity in synonymous sequence divergence, but the biological mechanisms underlying this rate variation remain unclear.We tracked the origin and evolutionary trajectory of mitochondrial rate variations by dense sampling in Ajugoideae and found differences in the timing and magnitude of rate acceleration for particular genes.The most divergent genes accelerated earlier, retained a high rate across Ajugoideae, and are generally devoid of RNA editing, whereas moderately diverged genes accelerated later and retained relatively higher RNA editing frequency.The acceleration of mutation rates correlates with increased guanine–cytosine (GC) content, suggesting a key role for GC‐biased gene conversion and/or repair after the breakage of ancestral gene clusters. [ABSTRACT FROM AUTHOR]

Inflammatory bowel disease (IBD) is a significant global health concern. The gut microbiota plays an essential role in the onset and development of IBD. Sanghuangporus (SH), a traditional Chinese medicinal mushroom, has excellent anti‐inflammatory effects and is effective at modulating the gut microbiota. Despite these attributes, the specific anticolitic effects of SH and the mechanisms through which the gut microbiota mediates its benefits remain unclear. Herein, we demonstrated that polyphenol‐rich extract from SH effectively alleviated the pathological symptoms of dextran sodium sulfate (DSS)‐induced colitis in mice by modulating the gut microbiota. Treatment with SH distinctly enriched Alistipes, especially Alistipes onderdonkii, and its metabolite 5‐hydroxyindole‐3‐acetic acid (5HIAA). Oral gavage of live A. onderdonkii or 5HIAA potently mitigated DSS‐induced colitis in mice. Moreover, both 5HIAA and SH significantly activated the aromatic hydrocarbon receptor (AhR), and the administration of an AhR antagonist abrogated their protective effects against colitis. These results underscore the potent efficacy of SH in diminishing DSS‐induced colitis through the promotion of A. onderdonkii and 5HIAA, ultimately activating AhR signaling. This study unveils potential avenues for developing therapeutic strategies for colitis based on the interplay between SH and the gut microbiota. Highlights: Sanghuangporus (SH) polyphenol extract potently alleviated symptoms of colon colitis in dextran sodium sulfate‐induced colitis mice.The gut microbiota especially Alistipes onderdonkii mediates the anticolitic effect of SH.The SH‐enriched microbial metabolite 5‐hydroxyindole‐3‐acetic acid exhibited an anticolitic effect via the activation of the aryl hydrocarbon receptor.The "gut microbiota‐metabolites‐signaling pathway" provides an effective perspective for the study of complex Chinese medicine systems. [ABSTRACT FROM AUTHOR]

Accurate species identification is key to conservation and phylogenetic inference. Living plant collections from botanical gardens/arboretum are important resources for the purpose of scientific research, but the proportion of cultivated plant misidentification are un-tested using DNA barcodes. Here, we assembled the next-generation barcode (complete plastid genome and complete nrDNA cistron) and mitochondrial genes from genome skimming data of Torreya species with multiple accessions for each species to test the species discrimination and the misidentification proportion of cultivated plants used in Torreya studies. A total of 38 accessions were included for analyses, representing all nine recognized species of genus Torreya. The plastid phylogeny showed that all 21 wild samples formed species-specific clades, except T. jiulongshanensis. Disregarding this putative hybrid, seven recognized species sampled here were successfully discriminated by the plastid genome. Only the T. nucifera accessions grouped into two grades. The species identification rate of the nrDNA cistron was 62.5%. The Skmer analysis based on nuclear reads from genome skims showed promise for species identification with seven species discriminated. The proportion of misidentified cultivated plants from arboreta/botanical gardens was relatively high with four accessions (23.5%) representing three species. Interspecific relationships within Torreya were fully resolved with maximum support by plastomes, where Torreya jackii was on the earliest diverging branch, though sister to T. grandis in the nrDNA cistron tree, suggesting that this is likely a hybrid species between T. grandis and an extinct Torreya ancestor lineage. The findings here provide quantitative insights into the usage of cultivated samples for phylogenetic study. [ABSTRACT FROM AUTHOR]

Background:Camellia, comprising more than 200 species, is a valuable economic commodity due to its enormously popular commercial products: tea leaves, flowers, and high-quality edible oils. It is the largest and most important genus in the family Theaceae. However, phylogenetic resolution of the species has proven to be difficult. Consequently, the interspecies relationships of the genus Camellia are still hotly debated. Phylogenomics is an attractive avenue that can be used to reconstruct the tree of life, especially at low taxonomic levels. Methodology/Principal Findings:Seven complete chloroplast (cp) genomes were sequenced from six species representing different subdivisions of the genus Camellia using Illumina sequencing technology. Four junctions between the single-copy segments and the inverted repeats were confirmed and genome assemblies were validated by PCR-based product sequencing using 123 pairs of primers covering preliminary cp genome assemblies. The length of the Camellia cp genome was found to be about 157kb, which contained 123 unique genes and 23 were duplicated in the IR regions. We determined that the complete Camellia cp genome was relatively well conserved, but contained enough genetic differences to provide useful phylogenetic information. Phylogenetic relationships were analyzed using seven complete cp genomes of six Camellia species. We also identified rapidly evolving regions of the cp genome that have the potential to be used for further species identification and phylogenetic resolution. Conclusions/Significance:In this study, we wanted to determine if analyzing completely sequenced cp genomes could help settle these controversies of interspecies relationships in Camellia. The results demonstrate that cp genome data are beneficial in resolving species definition because they indicate that organelle-based “barcodes”, can be established for a species and then used to unmask interspecies phylogenetic relationships. It reveals that phylogenomics based on cp genomes is an effective approach for achieving phylogenetic resolution between Camellia species. [ABSTRACT FROM AUTHOR]