The Euscaphis japonica genome and the evolution of malvids.

Malvids is one of the largest clades of rosids, includes 58 families and exhibits remarkable morphological and ecological diversity. Here, we report a high-quality chromosome-level genome assembly for Euscaphis japonica, an early-diverging species within malvids. Genome-based phylogenetic analysis suggests that the unstable phylogenetic position of E. japonica may result from incomplete lineage sorting and hybridization event during the diversification of the ancestral population of malvids. Euscaphis japonica experienced two polyploidization events: the ancient whole genome triplication event shared with most eudicots (commonly known as the γ event) and a more recent whole genome duplication event, unique to E. japonica. By resequencing 101 samples from 11 populations, we speculate that the temperature has led to the differentiation of the evergreen and deciduous of E. japonica and the completely different population histories of these two groups. In total, 1012 candidate positively selected genes in the evergreen were detected, some of which are involved in flower and fruit development. We found that reddening and dehiscence of the E. japonica pericarp and long fruit-hanging time promoted the reproduction of E. japonica populations, and revealed the expression patterns of genes related to fruit reddening, dehiscence and abscission. The key genes involved in pentacyclic triterpene synthesis in E. japonica were identified, and different expression patterns of these genes may contribute to pentacyclic triterpene diversification. Our work sheds light on the evolution of E. japonica and malvids, particularly on the diversification of E. japonica and the genetic basis for their fruit dehiscence and abscission.

Euscaphis japonica Kanitz Fruit Exerts Antiobesity Effects by Inhibiting the Early Stage of Adipogenic Differentiation.

During the worldwide COVID-19 outbreak, there was an increase in the prevalence of obesity, including childhood obesity, due to which the awareness of obesity and interest in treatment increased. Accordingly, we describe EJF (Euscaphis japonica Kanitz fruit) extract as a candidate for naturally derived antiobesity agents. In this study, we found that EJF is involved in the early stage of adipogenic differentiation in vitro and finally inhibits adipogenesis. We propose two mechanisms for the antiobesity effect of EJF. First, EJF inhibits MDI-induced mitotic clonal expansion (MCE) by inducing cell cycle arrest at the initiation of adipogenic differentiation. The second aims to regulate stability and activation at the protein level of IRS1, which initiates differentiation in the early stage of differentiation. As a result, it was found that the activation of Akt decreased, leading to the inhibition of the expression of adipogenesis-related transcription factors (PPARγ, C/EBPα) and the subsequent suppression of adipogenic differentiation. In summary, we suggest that EJF can inhibit adipogenesis and lipid accumulation by suppressing the early stage of adipogenic differentiation in 3T3-L1 adipocytes. These findings indicate that EJF's functionality could be beneficial in the treatment of obesity, particularly childhood obesity associated with adipocyte hyperplasia.

Genetic diversity and population structure of Euscaphis japonica, a monotypic species.

BACKGROUND: Understanding plant genetic diversity is important for effective conservation and utilization of genetic resources. Euscaphis japonica (Thunb.) Dippel, is a monotypic species with high phenotypic diversity, narrow distribution, and small population size. In this study, we estimated the genetic diversity and population structure of E. japonica using nine natural populations and inter-simple sequence repeat (ISSR) markers. Our results could provide a theoretical reference for future conservation and utilization of E. japonica. RESULTS: We obtained a total of 122 DNA bands, of which 121 (99.18%) were polymorphic. The average number of effective alleles (Ne = 1.4975), Nei's gene diversity index (H = 0.3016), and Shannon's information index (I = 0.4630) revealed that E. japonica possessed a high level of genetic diversity. We observed that E. japonica consisted of both deciduous and evergreen populations. UPGMA tree showed that the evergreen and deciduous E. japonica form a sister group. There is little genetic differentiation among geographic populations based on STRUCTURE analysis. The Dice's similarity coefficient between the deciduous and evergreen populations was low, and the Fst value was high, indicating that these two types of groups have high degree of differentiation. CONCLUSION: Rich genetic diversity has been found in E. japonica, deciduous E. japonica and evergreen E. japonica populations, and genetic variation mainly exists within the population. The low-frequency gene exchange between deciduous and evergreen populations may be the result of the differentiation of deciduous and evergreen populations. We suggest that in-situ protection, seed collection, and vegetative propagation could be the methods for maintenance and conservation of E. japonica populations.

The complete chloroplast genome of Euscaphis japonica (Thunb.) Kanitz (Staphyleaceae) isolated in Korea.

The complete chloroplast genome of Euscaphis japonica (Thunb.) Kanitz isolated in Korea is 160,606 bp long and has four subregions: 89,232 bp of large single-copy and 18,734 bp of small single-copy regions are separated by 26,320 bp of inverted repeat regions including 129 genes (84 CDS, 8 rRNAs, and 37 tRNAs) and three pseudogenes. There were 424 SNPs and 809 INDELs compared with the Chinese E. japonica, useful to develop markers for phylogeographic study of the species. Phylogenetic trees show that E. japonica, representing Crossosomatales, is nested within the Malvids clade, confirming previous studies.

The complete chloroplast genome sequence of Euscaphis japonica (Staphyleaceae).

Euscaphis japonica is not only an ideal ornamental plant, but also a traditional medicinal plant, which is an extremely valuable species to study. We determined the complete chloroplast genome sequence for E. japonica using Illumina sequencing technology. The complete chloroplast sequence is 160,467 bp in length, including a large single-copy (LSC) region of 88,716 bp, a small single-copy (SSC) region of 18,614 bp, and a pair of invert repeats (IR) regions of 26,568 bp. Plastid genome contains 142 genes, 46 protein-coding genes, 39 tRNA genes, and eight rRNA genes. Phylogenetic analysis base on 14 chloroplast genomes indicates that E. japonica forms an isolated clade and sisters to Glycosmis-Gossypium clade with strong support.

A new hexacyclic triterpene acid from the roots of Euscaphis japonica and its inhibitory activity on triglyceride accumulation.

A new taraxerene-type hexacyclic triterpene acid named (12R,13S)-3-methoxy-12,13-cyclo-taraxerene-2,14-diene-1-one-28-oic acid (1), together with a known compound 3,7-dihydroxy-5-octanolide (2), was isolated from the roots of Euscaphis japonica. The structure of new compound 1 was elucidated on the basis of NMR, HR-ESIMS and X-ray diffraction analysis. It showed promising inhibitory activity on oleic acid induced triglyceride accumulation on HepG2 cells.