Genetic Insights into the Extremely Dwarf Hibiscus syriacus var. micranthus: Complete Chloroplast Genome Analysis and Development of a Novel dCAPS Marker.

This study explored the chloroplast (cp) genomes of three Hibiscus syriacus (HS) specimens endemic to Korea possessing unique ornamental and conservation values: the dwarf H. syriacus var. micranthus (HSVM), renowned for its small stature and breeding potential; HS 'Tamra', a cultivar from Korea's southernmost islands, noteworthy for its distinctive beauty; and HS Natural Monument no. 521 (N.M.521), a specimen of significant lifespan and height. Given the scarcity of evolutionary studies on these specimens, we assembled and analyzed their cp genomes. We successfully assembled genomes spanning 160,000 to 160,100 bp and identified intraspecific variants. Among these, a unique ATA 3-mer insertion in the trnL-UAA region was identified in HSVM, highlighting its value as a genetic resource. Leveraging this finding, we developed a novel InDel dCAPS marker, which was validated across 43 cultivars, enhancing our ability to distinguish HSVM and its derivatives from other HS cultivars. Phylogenetic analysis involving 23 Malvaceae species revealed that HSVM forms a clade with woody Hibiscus species, closely associating with N.M.520, which may suggest a shared ancestry or parallel evolutionary paths. This investigation advances our understanding of the genetic diversity in Korean HS and offers robust tools for accurate cultivar identification, aiding conservation and breeding efforts.

Anti­obesity and immunostimulatory activity of Chrysosplenium flagelliferum in mouse preadipocytes 3T3­L1 cells and mouse macrophage RAW264.7 cells.

Chrysosplenium flagelliferum (CF) is known for its anti-inflammatory, antioxidant and antibacterial activities. However, there is a lack of research on its other pharmacological properties. In the present study, the bifunctional roles of CF in 3T3-L1 and RAW264.7 cells were investigated, focusing on its anti-obesity and immunostimulatory effects. In 3T3-L1 cells, CF effectively mitigated the accumulation of lipid droplets and triacylglycerol. Additionally, CF downregulated the peroxisome proliferator-activated receptor (PPAR)-γ and CCAAT/enhancer-binding protein α protein levels; however, this effect was impeded by the knockdown of ß-catenin using ß-catenin-specific small interfering RNA. Consequently, CF-mediated inhibition of lipid accumulation was also decreased. CF increased the protein levels of adipose triglyceride lipase and phosphorylated hormone-sensitive lipase, while decreasing those of perilipin-1. Moreover, CF elevated the protein levels of phosphorylated AMP-activated protein kinase and PPARγ coactivator 1-α. In RAW264.7 cells, CF enhanced the production of pro-inflammatory mediators, such as nitric oxide (NO), inducible NO synthase, interleukin (IL)-1ß, IL-6 and tumor necrosis factor-α, and increased their phagocytic capacities. Inhibition of Toll-like receptor (TLR)-4 significantly reduced the effects of CF on the production of pro-inflammatory mediators and phagocytosis, indicating its crucial role in facilitating these effects. CF-induced increase in the production of pro-inflammatory mediators was controlled by the activation of c-Jun N-terminal kinase (JNK) and nuclear factor (NF)-κB pathways, and TLR4 inhibition attenuated the phosphorylation of these kinases. The results of the pesent study suggested that CF inhibits lipid accumulation by suppressing adipogenesis and inducing lipolysis and thermogenesis in 3T3-L1 cells, while stimulating macrophage activation via the activation of JNK and NF-κB signaling pathways mediated by TLR4 in RAW264.7 cells. Therefore, CF simultaneously exerts both anti-obesity and immunostimulatory effects.

Effects of Drip Irrigation-Fertilization on Growth, Flowering, Photosynthesis and Nutrient Absorption of Containerized Seedlings of Hibiscus syriacus L. (Haeoreum).

The amount of irrigation and fertilization should be considered first for the production and standardization of high-quality H. syriacus L. seedlings using container seedlings. This study was conducted to investigate the optimal conditions suitable for container cultivation of hibiscus by analyzing growth and physiological responses according to the control of irrigation and fertilization. Therefore, in this study, H. syriacus L. for. Haeoreum (3-year-old hardwood cutting propagation), a fast-growing, was transplanted into a 40 L container. The irrigation amount per container was adjusted (0.2, 0.3 and 0.4 ton/yr/tree), and the amount of fertilizer applied (0, 69.0, 138.0 and 207.0 g/yr/tree). The growth rate according to the irrigation-fertilization treatment was higher in the 0.3 ton-138.0 g/yr/tree irrigation-fertilization treatment (p < 0.001). Total biomass yield and seedling quality index (SQI) were highest in the 0.3 ton-138.0 g/yr/tree irrigation-fertilization treatment (p < 0.001). The higher the fertilization concentration, the faster the flowering and the longer the flowering. The photosynthetic capacity of H. syriacus L. was reduced in bare root seedling cultivation and container-non-fertilized treatment. The chlorophyll fluorescence response was also affected by bare root cultivation and containerized seedling cultivation fertilization. Nutrient vector diagnosis showed "nutritional suitability" in the 0.3 ton-138.0 g/yr/tree treatment. Overall, containerized seedling cultivation was superior in growth, photosynthetic performance, photochemical efficiency, and nutrient storage capacity compared to bare root cultivation. These results be expected to contribute not only to the industrial production of excellent container seedlings of H. syriacus L. but also to the production of other woody plants.

Multivariate Analysis among Marker Compounds, Environmental Factors, and Fruit Quality of Schisandra chinensis at Different Locations in South Korea.

This study aimed to investigate the correlation among the contents of marker compounds, growth characteristics, and environmental factors of Schisandra chinensis fruits across South Korea. The fruits were collected from 36 cultivation sites in 28 regions across the country. We investigated nine growth characteristics, twelve soil physicochemical properties, eight meteorological data, and three marker compounds in this study. We optimized and validated an optimized method for quantifying marker compounds using UPLC and performed correlation analysis among the contents of marker compounds, growth characteristics, and environmental factors. The UPLC-UV method for analyzing marker compounds was validated by measuring linearity, LOD, LOQ, precision, and accuracy. The marker compounds were negatively correlated with the fruit size and sugar contents, and growth characteristics were negatively correlated with some physicochemical properties of the soil. The results of this study can be used as basic data for the standard cultural practices and quality control of S. chinensis fruits.

High-throughput discovery of plastid genes causing albino phenotypes in ornamental chimeric plants.

Chimeric plants composed of green and albino tissues have great ornamental value. To unveil the functional genes responsible for albino phenotypes in chimeric plants, we inspected the complete plastid genomes (plastomes) in green and albino leaf tissues from 23 ornamental chimeric plants belonging to 20 species, including monocots, dicots, and gymnosperms. In nine chimeric plants, plastomes were identical between green and albino tissues. Meanwhile, another 14 chimeric plants were heteroplasmic, showing a mutation between green and albino tissues. We identified 14 different point mutations in eight functional plastid genes related to plastid-encoded RNA polymerase (rpo) or photosystems which caused albinism in the chimeric plants. Among them, 12 were deleterious mutations in the target genes, in which early termination appeared due to small deletion-mediated frameshift or single nucleotide substitution. Another was single nucleotide substitution in an intron of the ycf3 and the other was a missense mutation in coding region of the rpoC2 gene. We inspected chlorophyll structure, protein functional model of the rpoC2, and expression levels of the related genes in green and albino tissues of Reynoutria japonica. A single amino acid change, histidine-to-proline substitution, in the rpoC2 protein may destabilize the peripheral helix of plastid-encoded RNA polymerase, impairing the biosynthesis of the photosynthesis system in the albino tissue of R. japonica chimera plant.

Complete chloroplast genome sequence of Hibiscus trionum Linnaeus 1753 (Malvaceae).

Hibiscus trionum L. is an annual herbaceous plant belonging to the Malvaceae family. It is native to Central Africa, however, is now naturalized in Europe and Asia including Korea. Here, we report the complete chloroplast genome assembly of H. trionum. The complete chloroplast genome comprises 160,530 bp and is divided into four typical regions: a large single-copy region of 89,272 bp, a pair of inverse repeats of 26,152 bp each, and a small single-copy region of 18,954 bp. A total of 131 genes were identified in this chloroplast, of which 86 were protein-coding, 37 were tRNA, and 8 were rRNA genes. The results of this study will serve as a key reference for further research on Hibiscus speciation.

Nutritional composition and phytochemical screening in different parts of Hibiscus syriacus L.

As the national flower of Korea, the Hibiscus syriacus L. (Rose of Sharon) is symbolic in its abundance and is a prominent feature of Korean culture. H. syriacus has played an important role in Korea, not only as an ornamental plant but also as an essential ingredient in folk remedies through its various parts. This study aimed to characterize the nutritional and biochemical composition of each plant unit of H. syriacus "Wonhwa." The units are namely: the petals, leaves, roots, and sprouts from its seeds. According to the results each unit produced, the sprouts had the highest content of amino acids and fatty acids which adhere to the requirements of nutritionally excellent food ingredients. The petals produced high quantities of glucose, sucrose, and fumaric acid, with the highest antioxidant activity among the four units. The main bioactive compounds detected in H. syriacus extracts in the four units were o-coumaric acid, p-coumaric acid, schaftoside, isoschaftoside, apigenin-6-C-glucoside-7-o-glucoside, and kaempferol-3-O-galactoside-7-O-rhamnoside. Overall, the highest number of bioactive compounds, 2 phenolic acids and 22 flavonoids, were identified in the petals. These results suggest the possibility of excellent pharmacological activity in the petals.

Anthocyanins from Hibiscus syriacus L. Inhibit Melanogenesis by Activating the ERK Signaling Pathway.

Hibiscus syriacus L. exhibited promising potential as a new source of food and colorants containing various anthocyanins. However, the function of anthocyanins from H. syriacus L. has not been investigated. In the current study, we evaluated whether anthocyanins from the H. syriacus L. varieties Pulsae and Paektanshim (PS and PTS) inhibit melanin biogenesis. B16F10 cells and zebrafish larvae were exposed to PS and PTS in the presence or absence of α-melanocyte-stimulating hormone (α-MSH), and melanin contents accompanied by its regulating genes and proteins were analyzed. PS and PTS moderately downregulated mushroom tyrosinase activity in vitro, but significantly decreased extracellular and intracellular melanin production in B16F10 cells, and inhibited α-MSH-induced expression of microphthalmia-associated transcription factor (MITF) and tyrosinase. PS and PTS also attenuated pigmentation in α-MSH-stimulated zebrafish larvae. Furthermore, PS and PTS activated the phosphorylation of extracellular signal-regulated kinase (ERK), whereas PD98059, a specific ERK inhibitor, completely reversed PS- and PTS-mediated anti-melanogenic activity in B16F10 cells and zebrafish larvae, which indicates that PS- and PTS-mediated anti-melanogenic activity is due to ERK activation. Moreover, chromatography data showed that PS and PTS possessed 17 identical anthocyanins as a negative regulator of ERK. These findings suggested that anthocyanins from PS and PTS inhibited melanogenesis in vitro and in vivo by activating the ERK signaling pathway.

The complete chloroplast genome sequence of Hibiscus syriacus.

The complete chloroplast genome sequence of Hibiscus syriacus L. is presented in this study. The genome is composed of 161 019 bp in length, with a typical circular structure containing a pair of inverted repeats of 25 745 bp of length separated by a large single-copy region and a small single-copy region of 89 698 bp and 19 831 bp of length, respectively. The overall GC content is 36.8%. One hundred and fourteen genes were annotated, including 81 protein-coding genes, 4 ribosomal RNA genes and 29 transfer RNA genes.