Search Results (32)

Background: Osteoporosis is characterized by the microstructural depletion of bone tissue and decreased bone density, leading to an increased risk of fractures. Cotoneaster wilsonii Nakai, an endemic species of the Korean Peninsula, grows wild in Ulleungdo. In this study, we aimed to investigate the effects of C. wilsonii and its components on osteoporosis. Methods and Results: The alkaline phosphatase (ALP) activity of C. wilsonii extracts and fractions was evaluated in MC3T3-E1 pre-osteoblasts, and the n-hexane fraction (CWH) showed the best properties for ALP activity. The effects of the CWH on bone formation were assessed in MC3T3-E1 cells and ovariectomized mice. Biochemical assays and histological analyses focused on the signaling activation of osteoblast differentiation and osteogenic markers, such as ALP, collagen, and osterix. The CWH significantly activated TGF-β and Wnt signaling, enhancing osteoblast differentiation and bone matrix formation. Notably, CWH treatment improved micro-CT indices, such as femoral bone density, and restored serum osteocalcin levels compared to OVX controls. Conclusions: These results highlight the potential of the C. wilsonii Nakai n-hexane fraction as a promising therapeutic agent for managing osteoporosis. Full article

Green leafy vegetables are rich in lipophilic metabolites such as carotenoids, phytosterols, tocopherols, and fatty acids, known for their significant health benefits. Goat’s beard (Aruncus dioicus var. kamtschaticus), a wild leafy vegetable native to Ulleungdo Island, South Korea, is reported to possess various biological activities and bioactive compounds. However, the content and profiles of lipophilic metabolites, especially carotenoids, have not been reported. This study investigated the composition of lipophilic metabolites in the foliage of goat’s beard using liquid chromatography–diode-array detection–mass spectrometry, gas chromatography–mass spectrometry, and gas chromatography–flame ionization detection. Five carotenoids (violaxanthin, neoxanthin, lactucaxanthin, lutein, β-carotene) and α-tocopherol were identified and quantified using liquid chromatography–diode-array detection–mass spectrometry. Lactucaxanthin, previously discovered in lettuce, was identified for the first time in goat’s beard foliage, with a higher concentration (45.42 ± 0.80 µg/g FW) compared to red lettuce (19.05 ± 0.67 µg/g FW). Furthermore, total carotenoids and α-tocopherol contents were higher in goat’s beard than in red lettuce. Gas chromatography–mass spectrometry analysis showed the presence of three phytosterols, namely, campesterol (3.53 ± 0.20 µg/g FW), stigmasterol (65.30 ± 4.87 µg/g FW), and β-sitosterol (89.54 ± 2.46 µg/g FW). Gas chromatography–flame ionization detection analysis revealed the presence of five essential fatty acids, with α-linolenic acid (57.03 ± 0.47%) being the most abundant, contributing to a favorable polyunsaturated FA/saturated FA ratio. These findings underscore the nutritional potential of a goat’s beard, suggesting its promising use in dietary supplements and the commercial extraction of valuable lipophilic antioxidants, particularly lactucaxanthin, for nutraceuticals and functional foods. Full article

Korean wasabi occurs naturally on the young oceanic, volcanic Ulleung Island off the east coast of the Korean Peninsula. Although the Ulleung Island wasabi is reported as Eutrema japonicum and has been suggested to be morphologically identical to cultivars in Korea, very little is known about its taxonomic identity and relationship with other cultivars. In this study, we sequenced the complete chloroplast DNA sequences of three naturally occurring Ulleung Island wasabi plants and six cultivars (‘Daewang’, ‘Daruma’, ‘Micado’, ‘Orochi’, ‘Green Thumb’, and ‘Shogun’) from continental Korea and determined the taxonomic identity of Korean wasabi on Ulleung Island. The size and organization of the complete chloroplast genomes of the nine accessions were nearly identical to those of previously reported wasabi cultivars. In addition, phylogenetic analysis based on the complete plastomes suggested that Ulleung Island wasabi most likely comprises various wasabi cultivars with three chlorotypes (‘Shogun’, ‘Green Thumb’, and a unique Chusan type). Based on the complete plastomes, we identified eight chlorotypes for the major wasabi cultivars and the Ulleung Island wasabi. Two major groups (1—‘Mazuma’ and ‘Daruma’, and 2—‘Fujidaruma’/‘Shimane No. 3’/Ulleung Island wasabi/five cultivars in Korea) were also identified based on mother line genealogical history. Furthermore, different types of variations (mutations, insertions/deletions (indels), mononucleotide repeats, and inversions) in plastomes were identified to distinguish different cultivar lines and five highly divergent hotspots. The nine newly obtained complete plastomes are valuable organelle genomic resources for species identification and infraspecific phylogeographic studies on wild and cultivated wasabi. Full article

Erigeron represents the third largest genus on the Juan Fernández Islands, with six endemic species, five of which occur exclusively on the younger Alejandro Selkirk Island with one species on both islands. While its continental sister species is unknown, Erigeron on the Juan Fernández Islands appears to be monophyletic and most likely evolved from South American progenitor species. We characterized the complete chloroplast genomes of five Erigeron species, including accessions of E. fernandezia and one each from Alejandro Selkirk and Robinson Crusoe Islands, with the purposes of elucidating molecular evolution and phylogenetic relationships. We found highly conserved chloroplast genomes in size, gene order and contents, and further identified several mutation hotspot regions. In addition, we found two positively selected chloroplast genes (ccsA and ndhF) among species in the islands. The complete plastome sequences confirmed the monophyly of Erigeron in the islands and corroborated previous phylogenetic relationships among species. New findings in the current study include (1) two major lineages, E. turricola–E. luteoviridis and E. fernandezia–E. ingae–E. rupicola, (2) the non-monophyly of E. fernandezia occurring on the two islands, and (3) the non-monophyly of the alpine species E. ingae complex. Full article

This taxonomic study investigates marine tubificids, with a focus on the genera Smithsonidrilus, Heterodrilus, Limnodriloides, and Tubificoides and presenting a new species, Heterodrilus koreanus n. sp., discovered in the around Ulleungdo and Dokdo Islands in the East Sea of the Republic of Korea. The new species, Heterodrilus koreanus n. sp., is characterized by a very long and slender atrium with prostate glands attached to the ventral side, with indistinct ducts and large round ampullae in the spermathecae. The four recorded species are: H. pentcheffi Erséus, 1981, Limnodriloides anxius Erséus, 1990, Smithsonidrilus exspectatus Erséus, 1993, and Tubificoides heterochaetus Michaelsen, 1926. This study not only enhances our comprehension of the intricate morphology within these genera but also contributes to the broader understanding of marine oligochaetes, particularly in the Korean marine ecosystem. Full article

Trichome is a hair-like structure involved in mechanical and chemical defenses of plants against herbivorous insects. Nicotiana benthamiana, a wild tobacco plant, has well-developed glandular trichomes that secrete sugar esters with potent repellent and insecticidal properties. However, there is a lack of information about the effectiveness of trichome extract in the control of plant-sapping insects. The objective of this study was to investigate the effects of N. benthamiana trichome exudates on Bemisia tabaci MED (Gennadius) (Hemiptera: Aleyrodidae), a highly destructive insect pest that poses significant threats to both vegetable and ornamental plants globally. First, we determined the host preference and mortality of B. tabaci adults using the choice test and feeding assay towards tomato and N. benthamiana plants. B. tabaci preferred tomato over N. benthamiana plants. Second, we extracted N. benthamiana trichome exudates by washing the leaves with either water or ethanol and evaluated their oral toxicities against B. tabaci adults using a parafilm feeding chamber containing 20% sucrose solution. Oral ingestion of both extracts significantly increased mortality in a concentration-dependent manner. Oral ingestion of ethanol-washed 10% trichome extract caused >60% mortality in B. tabaci adults after 36 h. Third, trichome exudates were concentrated by drying to obtain a powder form, which was more potent in killing whiteflies than the liquid form. Oral ingestion of 1% trichome powder was completely lethal to B. tabaci within 36 h. N. benthamiana trichome exudates are highly toxic to B. tabaci through oral ingestion, suggesting that N. benthamiana can be used as a potential natural pesticide for whitefly management. Full article

In 2016, the fall armyworm (FAW), Spodoptera frugiperda, invaded western Africa and rapidly spread in sub-Saharan Africa, causing significant losses in yields of corn, a major food crop in Africa. Although the Democratic Republic of the Congo (DRC) is a large corn-growing country, the impact of FAW has not been investigated. This study was designed to expand investigations on the genetic diversity of FAW populations in the DRC. We collected FAW individuals from eight provinces across the country, for analysis of genetic variation. Based on the partial sequences of both mitochondrial cytochrome oxidase subunit I (COI) and nuclear triosephosphate isomerase (Tpi) genes, we compared polymorphic features of the COI haplotype and Tpi single nucleotide polymorphisms. The results revealed that most (84%) of the analyzed individuals were heterogeneous hybrids Tpi-corn/COI-rice (Tpi-C/COI-R), whereas 16% were homogenous Tpi-corn/COI-corn (Tpi-C/COI-C). Further analysis of the fourth exon/intron sequences of the Tpi gene identified two subgroups, TpiCa1 and TpiCa2, constituting 80% and 20%, respectively, of the collected individuals. Analysis of genetic variation among native and invasive populations indicated significant genetic differences (10.94%) between the native American and DRC populations, whereas both the DRC and African populations were genetically closer to Asian than American populations. This study provides important information on FAW genetic diversity in the DRC, which can be used for effective management of FAW. Full article

Biological invasions are known to cause local extinctions on islands. Dok-do, a small, remote volcanic island in the East Sea of Korea in the western Pacific, has recently been invaded by rats, posing ecological problems. To infer their origin and invasion pathway, we collected rats from Dok-do and from the potential introduction source locations, Ulleung-do in the Pacific Ocean, and four east coastal ports. First, we identified that the brown rat (Rattus norvegicus) was the only rat species occurring at collecting sites based on the key morphological characteristics. To determine the population-level genetic diversity pattern, we applied the 3-RADseq approach. After a series of filtrations (minor allele frequency < 0.05, Hardy–Weinberg equilibrium p < 1 × 10⁻⁷), 4042 SNPs were retained for the final dataset from the 25,439 SNPs initially isolated. The spatial structure and genetic diversity pattern of brown rats suggested that the rat population on Dok-do was likely introduced from Ulleung-do. Our work provides practical information that will assist in the management of invasive brown rats in vulnerable island ecosystems. Full article

Bentinckia is a genus of flowering plants which is an unplaced member of the tribe Areceae (Arecaceae). Two species are recognized in the genus, viz. B. condapanna Berry ex Roxb. from the Western Ghats, India, and B. nicobarica (Kurz) Becc. from the Nicobar Islands. This work constitutes taxonomic revision, cytogenetics, molecular phylogeny, and biogeography of the Indian endemic palm genus Bentinckia. The present study discusses the ecology, morphology, taxonomic history, distribution, conservation status, and uses of Bentinckia. A neotype was designated for the name B. condapanna. Cytogenetical studies revealed a new cytotype of B. condapanna representing 2n = 30 chromosomes. Although many phylogenetic reports of the tribe Areceae are available, the relationship within the tribe is still ambiguous. To resolve this, we carried out Bayesian Inference (BI) and Maximum Likelihood (ML) analysis using an appropriate combination of chloroplast and nuclear DNA regions. The same phylogeny was used to study the evolutionary history of Areceae. Phylogenetic analysis revealed that Bentinckia forms a clade with other unplaced members, Clinostigma and Cyrostachys, and together they show a sister relationship with the subtribe Arecinae. Biogeographic analysis shows Bentinckia might have originated in Eurasia and India. Full article

The CHEMTAX program has been widely used to estimate community composition based on major pigment concentrations in seawater. However, because CHEMTAX is an underdetermined optimization algorithm, underdetermined bias has remained an unsolved problem since its development in 1996. The risk of producing biased results increases when analyzing the picophytoplankton community; therefore, this study tested a new method for avoiding biased CHEMTAX results using the picophytoplankton community around the East Sea (Japan Sea). This method involves building a linear model between pigment concentration data and community composition data based on DNA sequencing to predict the pigment range for each operational taxonomic unit, based on the 95% prediction interval. Finally, the range data are transformed into an initial ratio and ratio limits for CHEMTAX analysis. Three combinations of initial ratios and ratio limits were tested to determine whether the modeled initial ratio and ratio limit could prevent underdetermined bias in the CHEMTAX estimates; these combinations were the modeled initial ratio and ratio limit, the modeled initial ratio with a default ratio limit of 500 s, and an initial ratio from previous research with the default ratio limit. The final ratio and composition data for each combination were compared with Bayesian compositional estimator-based final ratio and composition data, which are robust against underdetermined bias. Only CHEMTAX analysis using the modeled initial ratio and ratio limit was unbiased; all other combinations showed significant signs of bias. Therefore, the findings in this study indicate that ratio limits and the initial ratio are equally important in the CHEMTAX analysis of biased datasets. Moreover, we obtained statistically supported initial ratios and ratio limits through linear modeling of pigment concentrations and 16s rDNA composition data. Full article

This study was conducted to elucidate the germination characteristics and dormancy types in Maianthemum dilatatum (A. W. Wood) A. Nelson and J. F. Macbr. M. dilatatum seeds were collected from the Nari Basin on Ulleungdo Island, South Korea and used in a water imbibition test; the seed weight increased by approximately 20% within 48 h. The embryo-to-seed ratio at the time of seed dispersal was 0.57 ± 0.03. When the seeds were incubated under light and dark conditions, they germinated under dark conditions, and the germination rate was higher at 25 °C than at 20 °C. However, the final germination rates under dark conditions were 27.4 ± 3.6 and 47.1 ± 7.6%, respectively. Under 4, 8, 12, and 16 weeks of cold stratification treatment, the highest germination rate of 83.6 ± 3.6% was observed at 25 °C at 12 weeks of cold stratification treatment, the germination start date was decreased by more than 10 d, and the mean germination time (MGT) was shortened from 50 d to 39 d. However, the germination rate, germination start date, and MGT did not differ significantly among the gibberellic acid hormone treatments. Therefore, it was evident that M. dilatatum demonstrated physiological dormancy (PD) that can broken by cold stratification treatment and dark conditions. Full article

Barleria cristata L., commonly known as the Philippine violet, is native to South Asia. It is an ornamental plant and is also used for the treatment of a variety of diseases. In India, it is found throughout the country in many forms, varying in its floral attributes (calyx and corolla) and habitat. In order to understand the species limits in B. cristata, we studied morphological as well as palynological variation and assessed the phylogenetic relationships among five different morphotypes. The studied morphotypes (populations) came from three phytogeographical regions, namely the Western Ghats, the Deccan Peninsula and the Western Himalaya. The naturally occurring populations from the Deccan Peninsula and the Western Himalaya showed conspicuous differences in their morphology. All the morphotypes had oblate spheroidal, tri-brevicolporate and honey-combed pollen grains which differed only in their quantitative parameters. The distinct-looking morphotypes, namely, Nandi Hills, Uttarakhand and cultivated morphotypes, could not be separated based on pollen characters. Phylogenetic analyses based on chloroplast DNA sequences revealed that our samples formed a clade sister to the B. cristata specimen used in the previous study. The genetic variation within morphotypes was not enough for the genomic regions investigated; however, it revealed among morphotype genealogies in detail. Phylogenetic analyses showed that there were three monophyletic groups within the B. cristata complex that exhibited some morphological differences. Nevertheless, based on the present sampling, it is not possible to delimit these morphotypes at specific or infraspecific level. To reach such conclusions, further investigations like sampling this species across its distribution range in India and assessment of intraspecific relationships, and their cytogenetical characterization should be done. Full article

The genus Portulaca L. belongs to the monogeneric family Portulacaceae and consists of about 157 species worldwide. In India, it is represented by 11 taxa; among them, Portulaca badamica, Portulaca lakshminarasimhaniana, Portulaca oleracea var. linearifolia, and Portulaca laljii are endemic. So far, the phylogenetic positions of these species have not yet been analyzed. We have reconstructed the Bayesian and maximum likelihood phylogenies based on a combined chloroplast and nuclear DNA sequence dataset to reveal phylogenetic placements of Indian Portulaca. Phylogenetic analyses indicate that all the sampled Indian Portulaca species (except Portulaca wightiana) are placed in the AL clade, which contains most of the known species of the family Portulacaceae. We used reconstructed phylogeny to study the historical biogeography of Indian endemic species by employing S-DIVA analysis. S-DIVA analysis suggested P. lakshminarasimhaniana has origin in India, it may be the result of in situ speciation in India, and P. badamica was dispersed from Africa to India. We have also discussed the systematic placements of endemic species and their morphological relationships with closely allied species. In addition, this study also provides taxonomic treatment for endemic species. Full article

Abiotic stress induces reactive oxygen species (ROS) generation in plants, and high ROS levels can cause partial or severe oxidative damage to cellular components that regulate the redox status. Here, we developed salt-tolerant transgenic rice plants that overexpressed the dehydroascorbate reductase gene (OsDHAR1) under the control of a stress-inducible sweet potato promoter (SWPA2). OsDHAR1-expressing transgenic plants exhibited improved environmental adaptability compared to wild-type plants, owing to enhanced ascorbate levels, redox homeostasis, photosynthetic ability, and membrane stability through cross-activation of ascorbate-glutathione cycle enzymes under paddy-field conditions, which enhanced various agronomic traits, including root development, panicle number, spikelet number per panicle, and total grain yield. dhar2-knockdown plants were susceptible to salt stress, and owing to poor seed maturation, exhibited reduced biomass (root growth) and grain yield under paddy field conditions. Microarray revealed that transgenic plants highly expressed genes associated with cell growth, plant growth, leaf senescence, root development, ROS and heavy metal detoxification systems, lipid metabolism, isoflavone and ascorbate recycling, and photosynthesis. We identified the genetic source of functional genomics-based molecular breeding in crop plants and provided new insights into the physiological processes underlying environmental adaptability, which will enable improvement of stress tolerance and crop species productivity in response to climate change. Full article

Cotoneaster is a taxonomically and ornamentally important genus in the family Rosaceae; however, phylogenetic relationships among its species are complicated owing to insufficient morphological diagnostic characteristics and hybridization associated with polyploidy and apomixis. In this study, we sequenced the complete plastomes of seven Cotoneaster species (C. dielsianus, C. hebephyllus, C. integerrimus, C. mongolicus, C. multiflorus, C. submultiflorus, and C. tenuipes) and included the available complete plastomes in a phylogenetic analysis to determine the origin of C. wilsonii, which is endemic to Ulleung Island, Korea. Furthermore, based on 15 representative lineages within the genus, we carried out the first comparative analysis of Cotoneaster plastid genomes to gain an insight into their molecular evolution. The plastomes were highly conserved, with sizes ranging from 159,595 bp (C. tenuipes) to 160,016 bp (C. hebephyllus), and had a GC content of 36.6%. The frequency of codon usage showed similar patterns among the 15 Cotoneaster species, and 24 of the 35 protein-coding genes were predicted to undergo RNA editing. Eight of the 76 common protein-coding genes, including ccsA, matK, ndhD, ndhF, ndhK, petA, rbcL, and rpl16, were positively selected, implying their potential roles in adaptation and speciation. Of the 35 protein-coding genes, 24 genes (15 photosynthesis-related, seven self-replications, and three others) were found to harbor RNA editing sites. Furthermore, several mutation hotspots were identified, including trnG-UCC/trnR-UCU/atpA and trnT-UGU/trnL-UAA. Maximum likelihood analysis based on 57 representative plastomes of Cotoneaster and two Heteromeles plastomes as outgroups revealed two major lineages within the genus, which roughly correspond to two subgenera, Chaenopetalum and Cotoneaster. The Ulleung Island endemic, C. wilsonii, shared its most recent common ancestor with two species, C. schantungensis and C. zabelii, suggesting its potential origin from geographically close members of the subgenus Cotoneaster, section Integerrimi. Full article