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BACKGROUND: The diagnosis of tuberculous pleurisy (TP) presents a significant challenge due to the low bacterial load in pleural effusion (PE) samples. Cell-free Mycobacterium tuberculosis DNA (cf-TB) in PE samples is considered an optimal biomarker for diagnosing TP. This study aimed to evaluate the applicability of cf-TB testing across diverse research sites with a relatively large sample size. METHODS: Patients suspected of TP and presenting with clinical symptoms and radiological evidence of PE were consecutively enrolled by treating physicians from 11 research sites across 6 provinces in China between April 2020 and August 2022. Following centrifugation, sediments obtained from PE were used for Xpert MTB/RIF (Xpert) and mycobacterial culture, while the supernatants were subjected to cf-TB testing. This study employed a composite reference standard to definite TP, which was characterized by any positive result for Mycobacterium tuberculosis (MTB) through either PE culture, PE Xpert, or pleural biopsy. RESULTS: A total of 1412 participants underwent screening, and 1344 (95.2%) were subsequently enrolled in this study. Data from 1241 (92.3%) participants were included, comprising 284 with definite TP, 677 with clinically diagnosed TP, and 280 without TP. The sensitivity of cf-TB testing in definite TP was 73.6% (95% CI 68.2-78.4), significantly higher than both Xpert (40.8%, 95% CI 35.3-46.7, P < 0.001) and mycobacterial culture (54.2%, 95% CI 48.4-59.9, P < 0.001). When clinically diagnosed TP was incorporated into the composite reference standard for sensitivity analysis, cf-TB testing showed a sensitivity of 46.8% (450/961, 95% CI 43.7-50.0), significantly higher than both Xpert (116/961, 12.1%, 95% CI 10.2-14.3, P < 0.001) and mycobacterial culture (154/961, 16.0%, 95% CI 13.8-18.5, P < 0.001). The specificities of cf-TB testing, Xpert, and mycobacterial culture were all 100.0%. CONCLUSIONS: The performance of cf-TB testing is significantly superior to that of Xpert and mycobacterial culture methods, indicating that it can be considered as the primary diagnostic approach for improving TP detection. Trial registration The trial was registered on Chictr.org.cn (ChiCTR2000031680, https://www.chictr.org.cn/showproj.html?proj=49316 ).
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ADN Bacteriano , Mycobacterium tuberculosis , Derrame Pleural , Tuberculosis Pleural , Humanos , Tuberculosis Pleural/diagnóstico , Femenino , Mycobacterium tuberculosis/genética , Estudios Transversales , Masculino , Persona de Mediana Edad , Adulto , Derrame Pleural/microbiología , Derrame Pleural/diagnóstico , China , ADN Bacteriano/análisis , Ácidos Nucleicos Libres de Células/análisis , Anciano , Sensibilidad y EspecificidadRESUMEN
BACKGROUND: Interest in the evolution of climatic niches, particularly in understanding the potential adaptive responses of species under climate change, has increased both theoretically and within macroecological studies. These studies have provided valuable insights into how climatic traits of species influence their niche evolution. In this study, we aim to investigate whether niche conservatism plays a role in the species diversification of Nymphaea, a group of aquatic plants with a cosmopolitan distribution that is facing severe habitat loss. We will use climatic models and phylogenetic data for 23 species to reconstruct Nymphaea's niche evolution, measure niche overlap, and assess disparity through time while testing for evolutionary models. RESULTS: There was a lot of overlap in niches both within and between groups, especially for species that can be found in many places. The breadth and peaks of the niche profile varied depending on the bioclimatic variables, which suggested that the species evolved differently to cope with changes in climate. The analysis also showed that evolutionary changes happened across the phylogeny, with weak to moderate signals. The morphological disparity index (MDI) values indicated that there were disparities within subclades over time but not between or among them. Niche reconstruction and evolution analysis revealed both convergent and divergent evolution among various variables. For example, N. immutabilis, N. atrans, N. violancea, and N. nouchali evolved towards intermediate temperatures for bio2 and bio3 (isothermity) while moving towards extreme temperatures for bio8 and bio9 (wettest and driest average quarterly temperatures). CONCLUSION: Our study will improve our understanding of how changes in climatic niches are potentially driving the evolution of Nymphaea. It has significant scientific implications for the limits, assemblages, evolution, and diversification of species. This information is crucial for the ongoing efforts of conservation and management, particularly considering the inevitable effects of climate change.
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Evolución Biológica , Clima , Ecosistema , Filogenia , América del Sur , Australia , África , Cambio ClimáticoRESUMEN
The baobab trees (genus Adansonia) have attracted tremendous attention because of their striking shape and distinctive relationships with fauna1. These spectacular trees have also influenced human culture, inspiring innumerable arts, folklore and traditions. Here we sequenced genomes of all eight extant baobab species and argue that Madagascar should be considered the centre of origin for the extant lineages, a key issue in their evolutionary history2,3. Integrated genomic and ecological analyses revealed the reticulate evolution of baobabs, which eventually led to the species diversity seen today. Past population dynamics of Malagasy baobabs may have been influenced by both interspecific competition and the geological history of the island, especially changes in local sea levels. We propose that further attention should be paid to the conservation status of Malagasy baobabs, especially of Adansonia suarezensis and Adansonia grandidieri, and that intensive monitoring of populations of Adansonia za is required, given its propensity for negatively impacting the critically endangered Adansonia perrieri.
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Adansonia , Filogenia , Adansonia/clasificación , Adansonia/genética , Biodiversidad , Conservación de los Recursos Naturales , Ecología , Especies en Peligro de Extinción , Evolución Molecular , Genoma de Planta/genética , Madagascar , Dinámica Poblacional , Elevación del Nivel del MarRESUMEN
Resource partitioning is considered a key factor in alleviating competitive interactions, enabling coexistence among consumer species. However, most studies have focused on resource partitioning between species, ignoring the potentially critical role of intraspecific variation in resource use. We investigated floral resource partitioning across species, colonies, and individuals in a species-rich bumblebee community in the diversification center of bumblebees. We used a total of 10,598 bumblebees belonging to 13 species across 5 years in the Hengduan Mountains of southwest China. First, we evaluated the influence of a comprehensive set of floral traits, including both those related to attractiveness (flower color and shape) and rewards (pollen, sugar ratio, nectar volume, sugar concentration, and amino acid content) on resource partitioning at the species level in bumblebee-plant networks. Then, we explored intraspecific resource partitioning on the colony and individual levels. Our results suggest that bumblebee species differ substantially in their use of the available floral resources, and that this mainly depends on flower attractiveness (floral color and shape). Interestingly, we also detected floral resource partitioning at the colony level within all commonest bumblebee species evaluated. In general, floral resource partitioning between bumblebee individuals decreased with species- and individual-level variation in body size (intertegular span). These results suggest that bumblebee species may coexist via the flexibility in their preferences for specific floral traits, which filters up to support the co-occurrence of high numbers of species and individuals in this global hotspot of species richness.
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Flores , Especificidad de la Especie , Animales , Abejas/fisiología , Flores/fisiología , China , EcosistemaRESUMEN
Background: Ginseng (Panax ginseng Mayer) is an important natural medicine. However, a long culture period and challenging quality control requirements limit its further use. Although artificial cultivation can yield a sustainable medicinal supply, research on the association between the transplantation and chaining of metabolic networks, especially the regulation of ginsenoside biosynthetic pathways, is limited. Methods: Herein, we performed Liquid chromatography tandem mass spectrometry based metabolomic measurements to evaluate ginsenoside accumulation and categorise differentially abundant metabolites (DAMs). Transcriptome measurements using an Illumina Platform were then conducted to probe the landscape of genetic alterations in ginseng at various ages in transplantation mode. Using pathway data and crosstalk DAMs obtained by MapMan, we constructed a metabolic profile of transplantation Ginseng. Results: Accumulation of active ingredients was not obvious during the first 4 years (in the field), but following transplantation, the ginsenoside content increased significantly from 6-8 years (in the wild). Glycerolipid metabolism and Glycerophospholipid metabolism were the most significant metabolic pathways, as Lipids and lipid-like molecule affected the yield of ginsenosides. Starch and sucrose were the most active metabolic pathways during transplantation Ginseng growth. Conclusion: This study expands our understanding of metabolic network features and the accumulation of specific compounds during different growth stages of this perennial herbaceous plant when growing in transplantation mode. The findings provide a basis for selecting the optimal transplanting time.
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Plant terrestrialization (i.e. the transition to a terrestrial environment) is a significant evolutionary event that has been intensively studied. While certain plant lineages, particularly in angiosperms, have re-adapted to freshwater habitats after colonizing terrene, however, the molecular mechanism of the terrestrial-freshwater (T-F) transition remains limited. Here, the basal monocot Araceae was selected as the study object to explore the T-F transition adaptation mechanism by comparative genomic analysis. Our findings revealed that the substitution rates significantly increased in the lineage of freshwater Araceae, which may promote their adaptation to the freshwater habitat. Additionally, 20 gene sets across all four freshwater species displayed signs of positive selection contributing to tissue development and defense responses in freshwater plants. Comparative synteny analysis showed that genes specific to submerged plants were enriched in cellular respiration and photosynthesis. In contrast, floating plants were involved in regulating gene expression, suggesting that gene and genome duplications may provide the original material for plants to adapt to the freshwater environment. Our study provides valuable insights into the genomic aspects of the transition from terrestrial to aquatic environments in Araceae, laying the groundwork for future research in the angiosperm.
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Araceae , Evolución Biológica , Genoma , Agua Dulce , Plantas , Cromosomas , FilogeniaRESUMEN
It is well documented that diabetes mellitus (DM) is strongly associated with cognitive decline and structural damage to the brain. Cognitive deficits appear early in DM and continue to worsen as the disease progresses, possibly due to different underlying mechanisms. Normal iron metabolism is necessary to maintain normal physiological functions of the brain, but iron deposition is one of the causes of some neurodegenerative diseases. Increasing evidence shows that iron overload not only increases the risk of DM, but also contributes to the development of cognitive impairment. The current review highlights the role of iron overload in diabetic cognitive impairment (DCI), including the specific location and regulation mechanism of iron deposition in the diabetic brain, the factors that trigger iron deposition, and the consequences of iron deposition. Finally, we also discuss possible therapies to improve DCI and brain iron deposition.
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Pollinators mediate interspecific and intraspecific plant-plant indirect interactions (competition vs. facilitation) via density-dependent processes, potentially shaping the dynamics of plant communities. However, it is still unclear which ecological drivers regulate density-dependent patterns, including scale, pollination niches (i.e., the main pollinator functional group) and floral attractiveness to pollinators. In this study, we conducted three-year field observations in Hengduan Mountains of southwest China. By gathering data for more than 100 animal-pollinated plant species, we quantified the effect (positive vs. negative) of conspecific and heterospecific flower density on pollination at two scales: plot-level (4 m2) and site-level (100-5000 m2). Then, we investigated how pollination niches and floral attractiveness to pollinators (estimated here as average per-flower visitation rates) modulated density-dependent pollination interactions. Pollinator visitation depended on conspecific and heterospecific flower density, with rare plants subjected to interspecific competition at the plot-level and interspecific facilitation at the site-level. Such interspecific competition at the plot-level was stronger for plants pollinated by diverse insects, while interspecific facilitation at the site-level was stronger for bee-pollinated plants. Moreover, we also found stronger positive conspecific density-dependence for plants with lower floral attractiveness at the site-level, meaning that they become more frequently visited when abundant. Our study indicates that the role of pollination in maintaining rare plants and plant diversity depends on the balance of density-dependent processes in species-rich communities. We show here that such balance is modulated by scale, pollination niches and floral attractiveness to pollinators, indicating the context-dependency of diversity maintenance mechanisms.
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Plantas , Polinización , Abejas , Animales , Polinización/fisiología , Flores/fisiología , Insectos , ChinaRESUMEN
BACKGROUND: To date, plastid genomes have been published for all but two holoparasitic angiosperm families. However, only a single or a few plastomes represent most of these families. Of the approximately 40 genera of holoparasitic angiosperms, a complete plastid genome sequence is available for only about half. In addition, less than 15 species are currently represented with more than one published plastid genome, most of which belong to the Orobanchaceae. Therefore, a significant portion of the holoparasitic plant plastome diversity remains unexplored. This limited information could hinder potential evolutionary pattern recognition as well as the exploration of inter- and intra-species plastid genome diversity in the most extreme holoparasitic angiosperms. RESULTS: Here, we report the first plastomes of Kenyan Hydnora abyssinica accessions. The plastomes have a typical quadripartite structure and encode 24 unique genes. Phylogenetic tree reconstruction recovers the Kenyan accessions as monophyletic and together in a clade with the Namibian H. abyssinica accession and the recently published H. arabica from Oman. Hydnora abyssinica as a whole however is recovered as non-monophyletic, with H. arabica nested within. This result is supported by distinct structural plastome synapomorphies as well as pairwise distance estimates that reveal hidden diversity within the Hydnora species in Africa. CONCLUSION: We propose to increase efforts to sample widespread holoparasitic species for their plastid genomes, as is the case with H. abyssinica, which is widely distributed in Africa. Morphological reinvestigation and further molecular data are needed to fully investigate the diversity of H. abyssinica along the entire range of distribution, as well as the diversity of currently synonymized taxa.
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Evolución Biológica , Genoma de Plastidios , Humanos , Filogenia , Kenia , PlantasRESUMEN
Globally, endemic species and natural habitats have been significantly impacted by climate change, and further considerable impacts are predicted. Therefore, understanding how endemic species are impacted by climate change can aid in advancing the necessary conservation initiatives. The use of niche modeling is becoming a popular topic in biological conservation to forecast changes in species distributions under various climate change scenarios. This study used the Australian Community Climate and Earth System Simulator version 1 (ACCESS-CM2) general circulation model of coupled model intercomparison project phase 6 (CMIP6) to model the current distribution of suitable habitat for the four threatened Annonaceae species endemic to East Africa (EA), to determine the impact of climate change on their suitable habitat in the years 2050 (average for 2041-2060) and 2070 (average for 2061-2080). Two shared socio-economic pathways (SSPs) SSP370 and SSP585 were used to project the contraction and expansion of suitable habitats for Uvariodendron kirkii, Uvaria kirkii, Uvariodendron dzomboense and Asteranthe asterias endemic to Kenya and Tanzania in EA. The current distribution for all four species is highly influenced by precipitation, temperature, and environmental factors (population, potential evapotranspiration, and aridity index). Although the loss of the original suitable habitat is anticipated to be significant, appropriate habitat expansion and contraction are projections for all species. More than 70% and 40% of the original habitats of Uvariodendron dzombense and Uvariodendron kirkii are predicted to be destroyed by climate change, respectively. Based on our research, we suggest that areas that are expected to shrink owing to climate change be classified as important protection zones for the preservation of Annonaceae species.
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Rubia podantha Diels is endemic to southwestern China and belongs to the family Rubiaceae. It is used in traditional Chinese medicines. To enrich the genetic data and resolve Rubiaceae's phylogeny, we assembled a complete chloroplast (cp) genome of R. podantha using Illumina HiSeq reads. The whole length of the cp genome was 154,866 bp. Annotation using PGA software found 113 genes, including 79 protein coding genes, 30 tRNA genes, and four rRNA genes. The large single-copy region was 84,717 bp, the inverted repeat B (IRa) region was 26,516 bp, the small single copy was 17,117 bp, and the inverted repeats B (IRb) region was 26,516 bp. Moreover, 64 SSRs were identified. Phylogenomic analysis using cp genomes of 109 Rubiaceae species found that R. podantha is closely related to R. cordifola. Rubiaceae was separated into three subfamilies: Ixoroideae, Cinchonoideae, and Rubiodeae. The genus Saprosma was not imbedded within the Spermacoceae alliance as reported in previous studies. Instead, it was imbedded within the Psychotrieae alliance. Divergence time estimation indicated that R. podantha split from its relative R. cordifolia around 1.25 million years ago. The assembled chloroplast genome in this study provided useful molecular information about the evolution of R. podantha and was a basis for phylogenetic analyses of Rubiaceae. Supplementary Information: The online version contains supplementary material available at 10.1007/s12298-023-01302-y.
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Sambucus L. is found in the family Viburnaceae (syn. Adoxaceae) and encompasses approximately 29 accepted species. The complex morphology of these species has caused continued confusion concerning their nomenclature, classification, and identification. Despite previous attempts to resolve taxonomic complexities in the Sambucus genus, there are still unclear phylogenetic relationships among several species. In this study, the newly obtained plastome of Sambucus williamsii Hance. as well as the populations of Sambucus canadensis L., Sambucus javanica Blume, and Sambucus adnata Wall. ex DC were sequenced, and their sizes, structural similarity, gene order, gene number, and guanine-cytosine (GC) contents were analyzed. The phylogenetic analyses were conducted using the whole chloroplast genomes and protein-coding genes (PCGs). The findings revealed that the chloroplast genomes of Sambucus species exhibited typical quadripartite double-stranded DNA molecules. Their lengths ranged from 158,012 base pairs (bp) (S. javanica) to 158,716 bp (S. canadensis L). Each genome comprised a pair of inverted repeats (IRs), which separated the large single-copy (LSC) and small single-copy (SSC) regions. In addition, the plastomes contained 132 genes, encompassing 87 protein-coding, 37 tRNA, and four rRNA genes. In the simple sequence repeat (SSR) analysis, A/T mononucleotides had the highest proportion, with the most repetitive sequences observed in S. williamsii. The comparative genome analyses showed high similarities in structure, order, and gene contents. The hypervariable regions in the studied chloroplast genomes were trnT-GGU, trnF-GAA, psaJ, trnL-UAG, ndhF, and ndhE, which may be used as candidate barcodes for species discrimination in Sambucus genus. Phylogenetic analyses supported the monophyly of Sambucus and revealed the separation of S. javanica and S. adnata populations. Sambucus chinensis Lindl. was nested within S. javanica in the same clade, collaborating their conspecific treatment. These outcomes indicate that the chloroplast genome of Sambucus plants is a valuable genetic resource for resolving taxonomic discrepancies at the lower taxonomic levels and can be applied in molecular evolutionary studies.
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Neuroinflammation plays a crucial role in the occurrence and development of cognitive impairment in type 2 diabetes mellitus (T2DM), but the specific injury mechanism is not fully understood. Astrocyte polarization has attracted new attention and has been shown to be directly and indirectly involved in neuroinflammation. Liraglutide has been shown to have beneficial effects on neurons and astrocytes. However, the specific protection mechanism still needs to be clarified. In this study, we assessed the levels of neuroinflammation and A1/A2-responsive astrocytes in the hippocampus of db/db mice and examined their relationships with iron overload and oxidative stress. First, in db/db mice, liraglutide alleviated the disturbance of glucose and lipid metabolism, increased the postsynaptic density, regulated the expression of NeuN and BDNF, and partially restored impaired cognitive function. Second, liraglutide upregulated the expression of S100A10 and downregulated the expression of GFAP and C3, and decreased the secretion of IL-1ß, IL-18, and TNF-α, which may confirm that it regulates the proliferation of reactive astrocytes and A1/A2 phenotypes polarize and attenuate neuroinflammation. In addition, liraglutide reduced iron deposition in the hippocampus by reducing the expression of TfR1 and DMT1 and increasing the expression of FPN1; at the same time, liraglutide by up-regulating the levels of SOD, GSH, and SOD2 expression, as well as downregulation of MDA levels and NOX2 and NOX4 expression to reduce oxidative stress and lipid peroxidation. The above may attenuate A1 astrocyte activation. This study preliminarily explored the effect of liraglutide on the activation of different astrocyte phenotypes and neuroinflammation in the hippocampus of a T2DM model and further revealed its intervention effect on cognitive impairment in diabetes. Focusing on the pathological consequences of astrocytes may have important implications for the treatment of diabetic cognitive impairment.
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Mt Elgon is an ancient transboundary volcanic mountain found at the Kenya-Uganda boarder possessing high plant diversity. This study documents an updated checklist of the mountain's vascular plants obtained through random-walk field excursions and retrieval of herbarium specimen tracing back to 1900. We compiled 1709 species from 673 genera in 131 families. One new species of the family Cucurbitaceae was also reported. This checklist records respective habitat, habits, elevation ranges, voucher numbers and global distribution ranges of each species. Native and exotic species were also distinguished, where 8.4% of the total species in 49 families were exotic species. There were 103 endemic species, while 14 species were found to be both rare and endemic. IUCN conservation status revealed 2 Critically Endangered, 4 Endangered, 9 Vulnerable and 2 Near Threatened species. This study presents the first and most comprehensive plant inventory of Mt Elgon that will facilitate further ecological and phylogenetic studies.
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China covers a vast territory harbouring a large number of aquatic plants. Although there are many studies on the ß-diversity of total, herbaceous or woody plants in China and elsewhere, few studies have focused on aquatic plants. Here, we analyse a comprehensive data set of 889 aquatic angiosperm species in China, and explore the geographic patterns and climatic correlates of total taxonomic and phylogenetic ß-diversity as well as their turnover and nestedness components. Our results show that geographic patterns of taxonomic and phylogenetic ß-diversity are highly congruent for aquatic angiosperms, and taxonomic ß-diversity is consistently higher than phylogenetic ß-diversity. The ratio between the nestedness component and total ß-diversity is high in northwestern China and low in southeastern China. The geographic patterns of taxonomic and phylogenetic ß-diversity of aquatic angiosperms in China are obviously affected by geographic and climatic distances, respectively. In conclusion, the geographic patterns of taxonomic and phylogenetic ß-diversity of aquatic angiosperms are consistent across China. Climatic and geographic distances jointly affect the geographic patterns of ß-diversity of aquatic angiosperms. Overall, our work provides insight into understanding the large-scale patterns of aquatic angiosperm ß-diversity, and is a critical addition to previous studies on the macroecological patterns of terrestrial organisms.
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Globally, food and medicinal plants have been documented, but their use patterns are poorly understood. Useful plants are non-random subsets of flora, prioritizing certain taxa. This study evaluates orders and families prioritized for medicine and food in Kenya, using three statistical models: Regression, Binomial, and Bayesian approaches. An extensive literature search was conducted to gather information on indigenous flora, medicinal and food plants. Regression residuals, obtained using LlNEST linear regression function, were used to quantify if taxa had unexpectedly high number of useful species relative to the overall proportion in the flora. Bayesian analysis, performed using BETA.INV function, was used to obtain superior and inferior 95% probability credible intervals for the whole flora and for all taxa. To test for the significance of individual taxa departure from the expected number, binomial analysis using BINOMDIST function was performed to obtain p-values for all taxa. The three models identified 14 positive outlier medicinal orders, all with significant values (p < 0.05). Fabales had the highest (66.16) regression residuals, while Sapindales had the highest (1.1605) R-value. Thirty-eight positive outlier medicinal families were identified; 34 were significant outliers (p < 0.05). Rutaceae (1.6808) had the highest R-value, while Fabaceae had the highest regression residuals (63.2). Sixteen positive outlier food orders were recovered; 13 were significant outliers (p < 0.05). Gentianales (45.27) had the highest regression residuals, while Sapindales (2.3654) had the highest R-value. Forty-two positive outlier food families were recovered by the three models; 30 were significant outliers (p < 0.05). Anacardiaceae (5.163) had the highest R-value, while Fabaceae had the highest (28.72) regression residuals. This study presents important medicinal and food taxa in Kenya, and adds useful data for global comparisons.
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Moringa is a mono-genus belonging to the Moringaceae family, which includes 13 species. Among them, Moringa peregrina is plant species native to the Arabian Peninsula, Southern Sinai in Egypt, and the Horn of Africa, and comprehensive studies on its nutritional, industrial, and medicinal values have been performed. Herein, we sequenced and analyzed the initial complete chloroplast genome of Moringa peregrina. Concurrently, we analyzed the new chloroplast genome along with 25 chloroplast genomes related to species representing eight families in the Brassicales order. The results indicate that the plastome sequence of M. peregrina consists of 131 genes, with an average GC content of 39.23%. There is a disparity in the IR regions of the 26 species ranging from 25,804 to 31,477 bp. Plastome structural variations generated 20 hotspot regions that could be considered prospective DNA barcode locations in the Brassicales order. Tandem repeats and SSR structures are reported as significant evidence of structural variations among the 26 tested specimens. Furthermore, selective pressure analysis was performed to estimate the substitution rate within the Moringaceae family, which revealing that the ndhA and accD genes are under positive selective pressure. The phylogenetic analysis of the Brassicales order produced an accurate monophyletic annotation cluster of the Moringaceae and Capparaceae species, offering unambiguous identification without overlapping groups between M. oleifera and M. peregrina, which are genetically strongly associated. Divergence time estimation suggests that the two Moringa species recently diversified, 0.467 Ma. Our findings highlight the first complete plastome of the Egyptian wild-type of M. peregrina, which can be used for determining plastome phylogenetic relationships and systematic evolution history within studies on the Moringaceae family.
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BACKGROUND: The genus Veronicastrum Heist. ex Fabr. are mainly distributed in East Asia, and only Veronicastrum virginicum (L.) Farw. is disjunctively distributed in eastern North America. The south area of China (extending to Taiwan Island) is the richest in Veronicastrum species. It is of medicinal importance in China as traditional herbs used to treat ascites diseases that caused by schistosomiasis. During field investigation of plant resources in Pingbaying National Forest Park, Southwestern Hubei, China, an unknown flowering population of Veronicastrum was discovered from thick humus layers adjacent to rocks under broad-leaved forests by walkways. They were collected and morphological characters assesed for further taxonomic treatment. Molecular analysis was also conducted to ascertain its phylogenetic position in the genus Veronicastrum. RESULTS: This species is similar to Veronicastrum liukiuense (Ohwi) T.Yamaz. from the Ryukyu Islands, but can be distinctly differed by its axillary inflorescences (versus terminal on short leafy branches), pedicels up to 2.5 mm (versus sessile), corollas purple to purple-red (versus white tinged with pale purple) and florescence June to July (versus September to October). Also, phylogenetic studies showed the species was an independent clade in the genus Veronicastrum based on the maximum likelihood (ML) analyses using two different matrix sequences of concatenated molecular markers. The plastid genome of this new species is also reported in this study for the first time. CONCLUSION: The morphological and molecular evidences support the recognition of Veronicastrum wulingense as a new species.
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Apocynaceae are one of the ten species-richest angiosperm families. However, the backbone phylogeny of the family is yet less well supported, and the evolution of plastome structure has not been thoroughly studied for the whole family. Herein, a total of 101 complete plastomes including 35 newly sequenced, 24 reassembled from public raw data and the rest from the NCBI GenBank database, representing 26 of 27 tribes of Apocynaceae, were used for comparative plastome analysis. Phylogenetic analyses were conducted using a combined plastid data matrix of 77 protein-coding genes from 162 taxa, encompassing all tribes and 41 of 49 subtribes of Apocynaceae. Plastome lengths ranged from 150,897 bp in Apocynum venetum to 178,616 bp in Hoya exilis. Six types of boundaries between the inverted repeat (IR) regions and single copy (SC) regions were identified. Different sizes of IR expansion were found in three lineages, including Alyxieae, Ceropegieae and Marsdenieae, suggesting multiple expansion events of the IRs over the SC regions in Apocynaceae. The IR regions of Marsdenieae evolved in two ways: expansion towards the large single copy (LSC) region in Lygisma + Stephanotis + Ruehssia + Gymnema (Cosmopolitan clade), and expansion towards both LSC and small single copy (SSC) region in Dischidia-Hoya alliance and Marsdenia (Asia-Pacific clade). Six coding genes and five non-coding regions were identified as highly variable, including accD, ccsA-ndhD, clpP, matK, ndhF, ndhG-ndhI, trnG(GCC)-trnfM(CAU), trnH(GUG)-psbA, trnY(GUA)-trnE(UUC), ycf1, and ycf2. Maximum likelihood and Bayesian phylogenetic analyses resulted in nearly identical tree topologies and produced a well-resolved backbone comprising 15 consecutive dichotomies that subdivided Apocynaceae into 15 clades. The subfamily Periplocoideae were embedded in the Apocynoid grade and were sister to the Echiteae-Odontadenieae-Mesechiteae clade with high support values. Three tribes (Melodineae, Vinceae, and Willughbeieae), the subtribe Amphineuriinae, and four genera (Beaumontia, Ceropegia, Hoya, and Stephanotis) were not resolved as monophyletic. Our work sheds light on the backbone phylogenetic relationships in the family Apocynaceae and offers insights into the evolution of Apocynaceae plastomes using the most densely sampled plastome dataset to date.
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Apocynaceae , Magnoliopsida , Humanos , Filogenia , Apocynaceae/genética , Teorema de Bayes , Evolución Molecular , Magnoliopsida/genéticaRESUMEN
PREMISE: A major goal of systematic biology is to uncover the evolutionary history of organisms and translate that knowledge into stable classification systems. Here, we integrate three sets of genome-wide data to resolve phylogenetic relationships in Cornaceae (containing only Cornus s.l.), reconstruct the biogeographic history of the clade, and provide a revised classification using the PhyloCode to stabilize names for this taxonomically controversial group. METHODS: We conducted phylogenetic analyses using 312 single-copy nuclear genes and 70 plastid genes from Angiosperms353 Hyb-Seq, plus numerous loci from RAD-Seq. We integrated fossils using morphological data and produced a dated phylogeny for biogeographical analysis. RESULTS: A well-resolved, strongly supported, comprehensive phylogeny was obtained. Biogeographic analyses support an origin and rapid diversification of Cornus into four morphologically distinct major clades in the Northern Hemisphere (with an eastern Asian ancestor) during the late Cretaceous. Dispersal into Africa from eastern Asia likely occurred along the Tethys Seaway during the Paleogene, whereas dispersal into South America likely occurred during the Neogene. Diversification within the northern hemisphere likely involved repeated independent colonization of new areas during the Paleogene and Neogene along the Bering Land Bridge, the North Atlantic Land Bridge, and the Tethys Seaway. Thirteen strongly supported clades were named following rules of the PhyloCode. CONCLUSIONS: Our study provides an example of integrating genomic and morphological data to produce a robust, explicit species phylogeny that includes fossil taxa, which we translate into an updated classification scheme using the PhyloCode to stabilize names.