Cryo-EM structures of the plant plastid-encoded RNA polymerase.

Chloroplasts are green plastids in the cytoplasm of eukaryotic algae and plants responsible for photosynthesis. The plastid-encoded RNA polymerase (PEP) plays an essential role during chloroplast biogenesis from proplastids and functions as the predominant RNA polymerase in mature chloroplasts. The PEP-centered transcription apparatus comprises a bacterial-origin PEP core and more than a dozen eukaryotic-origin PEP-associated proteins (PAPs) encoded in the nucleus. Here, we determined the cryo-EM structures of Nicotiana tabacum (tobacco) PEP-PAP apoenzyme and PEP-PAP transcription elongation complexes at near-atomic resolutions. Our data show the PEP core adopts a typical fold as bacterial RNAP. Fifteen PAPs bind at the periphery of the PEP core, facilitate assembling the PEP-PAP supercomplex, protect the complex from oxidation damage, and likely couple gene transcription with RNA processing. Our results report the high-resolution architecture of the chloroplast transcription apparatus and provide the structural basis for the mechanistic and functional study of transcription regulation in chloroplasts.

The ligation between ERMAP, galectin-9 and dectin-2 promotes Kupffer cell phagocytosis and antitumor immunity.

Kupffer cells, the liver tissue resident macrophages, are critical in the detection and clearance of cancer cells. However, the molecular mechanisms underlying their detection and phagocytosis of cancer cells are still unclear. Using in vivo genome-wide CRISPR-Cas9 knockout screening, we found that the cell-surface transmembrane protein ERMAP expressed on various cancer cells signaled to activate phagocytosis in Kupffer cells and to control of liver metastasis. ERMAP interacted with ß-galactoside binding lectin galectin-9 expressed on the surface of Kupffer cells in a manner dependent on glycosylation. Galectin-9 formed a bridging complex with ERMAP and the transmembrane receptor dectin-2, expressed on Kupffer cells, to induce the detection and phagocytosis of cancer cells by Kupffer cells. Patients with low expression of ERMAP on tumors had more liver metastases. Thus, our study identified the ERMAP-galectin-9-dectin-2 axis as an 'eat me' signal for Kupffer cells.

Facet-switching of rate-determining step on copper in CO2-to-ethylene electroreduction.

Reduction of carbon dioxide (CO2) by renewable electricity to produce multicarbon chemicals, such as ethylene (C2H4), continues to be a challenge because of insufficient Faradaic efficiency, low production rates, and complex mechanistic pathways. Here, we report that the rate-determining steps (RDS) on common copper (Cu) surfaces diverge in CO2 electroreduction, leading to distinct catalytic performances. Through a combination of experimental and computational studies, we reveal that C─C bond-making is the RDS on Cu(100), whereas the protonation of *CO with adsorbed water becomes rate-limiting on Cu(111) with a higher energy barrier. On an oxide-derived Cu(100)-dominant Cu catalyst, we reach a high C2H4 Faradaic efficiency of 72%, partial current density of 359 mA cm-2, and long-term stability exceeding 100 h at 500 mA cm-2, greatly outperforming its Cu(111)-rich counterpart. We further demonstrate constant C2H4 selectivity of >60% over 70 h in a membrane electrode assembly electrolyzer with a full-cell energy efficiency of 23.4%.

Biphasic regulation of miR-17∼92 transcription during hypoxia: roles of HIF1 and p53 hyperphosphorylation at ser15.

We have reported previously that during hypoxia exposure, the expression of mature miR-17∼92 was first upregulated and then downregulated in pulmonary artery smooth muscle cells (PASMC) and in mouse lungs in vitro and in vivo. Here, we investigated the mechanisms regulating this biphasic expression of miR-17∼92 in PASMC in hypoxia. We measured the level of primary miR-17∼92 in PASMC during hypoxia exposure and found that short-term hypoxia exposure (3% O2, 6 h) induced the level of primary miR-17∼92, whereas long-term hypoxia exposure (3% O2, 24 h) decreased its level, suggesting a biphasic regulation of miR-17∼92 expression at the transcriptional level. We found that short-term hypoxia-induced upregulation of miR-17∼92 was hypoxia-inducible factor 1α (HIF1α) and E2F1 dependent. Two HIF1α binding sites on miR-17∼92 promoter were identified. We also found that long-term hypoxia-induced suppression of miR-17∼92 expression could be restored by silencing of p53. Mutation of the p53-binding sites in the miR-17∼92 promoter increased miR-17∼92 promoter activity in both normoxia and hypoxia. Our findings suggest that the biphasic transcriptional regulation of miR-17∼92 during hypoxia is controlled by HIF1/E2F1 and p53 in PASMC: during short-term hypoxia exposure, stabilization of HIF1 and induction of E2F1 induce the transcription of miR-17∼92, whereas during long-term hypoxia exposure, hyperphosphorylation of p53 suppresses the expression of miR-17∼92.NEW & NOTEWORTHY We showed that the biphasic transcriptional regulation of miR-17∼92 during hypoxia is controlled by two distinct mechanisms: during short-term hypoxia exposure, induction of HIF1 and E2F1 upregulates miR-17∼92. Longer hypoxia exposure induces hyperphosphorylation of p53 at ser15, which leads to its binding to miR-17∼92 promoter and inhibition of its expression. Our findings provide novel insights into the spatiotemporal regulation of miR-17∼92 that may play a role in the development of human lung diseases including pulmonary hypertension (PH).

Preclinical testing of CT1113, a novel USP28 inhibitor, for the treatment of T-cell acute lymphoblastic leukaemia.

T-cell acute lymphoblastic leukaemia (T-ALL) is a highly aggressive and heterogeneous lymphoid malignancy with poor prognosis in adult patients. Aberrant activation of the NOTCH1 signalling pathway is involved in the pathogenesis of over 60% of T-ALL cases. Ubiquitin-specific protease 28 (USP28) is a deubiquitinase known to regulate the stability of NOTCH1. Here, we report that genetic depletion of USP28 or using CT1113, a potent small molecule targeting USP28, can strongly destabilize NOTCH1 and inhibit the growth of T-ALL cells. Moreover, we show that USP28 also regulates the stability of sterol regulatory element binding protein 1 (SREBP1), which has been reported to mediate increased lipogenesis in tumour cells. As the most critical transcription factor involved in regulating lipogenesis, SREBP1 plays an important role in the metabolism of T-ALL. Therefore, USP28 may be a potential therapeutic target, and CT1113 may be a promising novel drug for T-ALL with or without mutant NOTCH1.

Repetition rate tuning and locking of solitons in a microrod resonator.

Recently, there has been significant interest in the generation of coherent temporal solitons in optical microresonators. In this Letter, we present a demonstration of dissipative Kerr soliton generation in a microrod resonator using an auxiliary-laser-assisted thermal response control method. In addition, we are able to control the repetition rate of the soliton over a range of 200 kHz while maintaining the pump laser frequency, by applying external stress tuning. Through the precise control of the PZT voltage, we achieve a stability level of 3.9 × 10-10 for residual fluctuation of the repetition rate when averaged 1 s. Our platform offers precise tuning and locking capabilities for the repetition frequency of coherent mode-locked combs in microresonators. This advancement holds great potential for applications in spectroscopy and precision measurements.

Modeling autosomal dominant retinitis pigmentosa by using patient-specific retinal organoids with a class-3 RHO mutation.

Rhodopsin-mediated autosomal dominant retinitis pigmentosa (RHO-adRP) causes progressive vision loss and is potentially incurable, accounting for 25% of adRP cases. Studies on RHO-adRP mechanism were at large based on the biochemical and cellular properties, especially class-3. Nonetheless, the absence of an appropriate model for class-3 RHO-adRP has impeded comprehensive exploration. Here, induced pluripotent stem cells (iPSCs) were generated from a healthy control and two sibling RP patients with the same point mutation, c.403C>T (p.R135W). The first three-dimensional (3D) retinal organoid model of a class-3 RHO point mutation from patient-derived iPSCs was generated. Significant defects were observed in rod photoreceptors in terms of localization, morphology, transcriptional profiling and single cell resolution, to better understand the human disease resulting from RHO mutations from a developmental perspective. This first human model of class-3 RHO-adRP provides a representation of patient's retina in vitro and displays features of RHO-adRP retinal organoids relevant for therapeutic development.

Effects of fluorescent protein tdTomato on mouse retina.

Fluorescent proteins (FPs) have been widely used to investigate cellular and molecular interactions and trace biological events in many applications. Some of the FPs have been demonstrated to cause undesirable cellular damage by light-induced ROS production in vivo or in vitro. However, it remains unknown if one of the most popular FPs, tdTomato, has similar effects in neuronal cells. In this study, we discovered that tdTomato expression led to unexpected retinal dysfunction and ultrastructural defects in the transgenic mouse retina. The retinal dysfunction mainly manifested in the reduced photopic electroretinogram (ERG) responses and decreased contrast sensitivity in visual acuity, caused by mitochondrial damages characterized with cellular redistribution, morphological modifications and molecular profiling alterations. Taken together, our findings for the first time demonstrated the retinal dysfunction and ultrastructural defects in the retinas of tdTomato-transgenic mice, calling for a more careful design and interpretation of experiments involved in FPs.

Hainanenin-1, an oncolytic peptide, triggers immunogenic cell death via STING activation in triple-negative breast cancer.

BACKGROUND: In triple-negative breast cancer (TNBC) therapy, insufficient tumor infiltration by lymphocytes significantly hinders the efficacy of immune checkpoint inhibitors. We have previously demonstrated that Hainanenin-1 (HN-1), a host defense peptide (HDP) identified from Hainan frog skin, induces breast cancer apoptosis and boots anti-tumor immunity via unknown mechanism. METHODS: We used in vitro experiments to observe immunogenic cell death (ICD) indicators in HN-1-treated TNBC cell lines, a mouse tumor model to verify HN-1 promotion of mice anti-tumor immune response, and an in vitro drug sensitivity test of patient-derived breast cancer cells to verify the inhibitory effect of HN-1. RESULTS: HN-1 induced ICD in TNBC in a process during which damage-associated molecular patterns (DAMPs) were released that could further increase the anti-tumor immune response. The secretion level of interleukin 2 (IL-2), IL-12, and interferon γ in the co-culture supernatant was increased, and dendritic cells (DCs) were activated via a co-culture with HN-1-pretreated TNBC cells. As a result, HN-1 increased the infiltration of anti-tumor immune cells (DCs and T lymphocytes) in the mouse model bearing both 4T1 and EMT6 tumors. Meanwhile, regulatory T cells and myeloid-derived suppressor cells were suppressed. In addition, HN-1 induced DNA damage, and double-strand DNA release in the cytosol was significantly enhanced, indicating that HN-1 might stimulate ICD via activation of STING pathway. The knockdown of STING inhibited HN-1-induced ICD. Of note, HN-1 exhibited inhibitory effects on patient-derived breast cancer cells under three-dimensional culture conditions. CONCLUSIONS: Collectively, our study demonstrated that HN-1 could be utilized as a potential compound that might augment immunotherapy effects in patients with TNBC.

Trends in cardiovascular health among US adults by glycemic status based on Life's Essential 8.

OBJECTIVE: We aimed to assess the secular trends in cardiovascular health (CVH) among U.S. adults with different glycemic statuses based on the Life's Essential 8 (LE8). METHODS: This cross-sectional study used nationally representative data from 6 cycles of the National Health and Nutrition Examination Surveys between 2007 and 2018. Survey-weighted linear models were used to assess time trends in LE8 scores. Stratified analyses and sensitivity analyses were conducted to validate the stability of the results. RESULTS: A total of 23,616 participants were included in this study. From 2007 to 2018, there was no significant improvement in overall CVH and the proportion of ideal CVH among participants with diabetes and prediabetes. We observed an opposite trend between health behavior and health factors in the diabetes group, mainly in increasing physical activity scores and sleep scores (P for trend<0.001), and declining BMI scores [difference, -6.81 (95% CI, -12.82 to -0.80)] and blood glucose scores [difference, -6.41 (95% CI, -9.86 to -2.96)]. Dietary health remained at a consistently low level among participants with different glycemic status. The blood lipid scores in the prediabetes group improved but were still at a lower level than other groups. Education/income differences persist in the CVH of participants with diabetes or prediabetes, especially in health behavior factors. Sensitivity analyses of the absolute difference and change in proportion showed a consistent trend. CONCLUSIONS: Trends in CVH among participants with diabetes or prediabetes were suboptimal from 2007 to 2018, with persistent education/income disparities.

The association between prenatal bisphenol F exposure and infant neurodevelopment: The mediating role of placental estradiol.

BACKGROUND: There are limited population studies on the neurodevelopmental effects of bisphenol F (BPF), a substitute for bisphenol A. Furthermore, the role of placental estradiol as a potential mediator linking these two factors remains unclear. OBJECTIVE: To examine the association between maternal prenatal BPF exposure and infant neurodevelopment in a prospective cohort study and to explore the mediating effects of placental estradiol between BPF exposure and neurodevelopment in a nested case-control study. METHODS: The prospective cohort study included 1077 mother-neonate pairs from the Wuhu city cohort study in China. Maternal BPF was determined using the liquid/liquid extraction and Ultra-performance liquid chromatography tandem mass spectrometry method. Children's neurodevelopment was assessed at ages 3, 6, and 12 months using Ages and Stages Questionnaires. The nested case-control study included 150 neurodevelopmental delay cases and 150 healthy controls. Placental estradiol levels were measured using enzyme-linked immunosorbent assay kits. Generalized estimating equation models and robust Poisson regression models were used to examine the associations between BPF exposure and children's neurodevelopment. In the nested case-control study, causal mediation analysis was conducted to assess the role of placental estradiol as a mediator in multivariate models. RESULTS: In the prospective cohort study, the pregnancy-average BPF concentration was positively associated with developmental delays in gross-motor, fine-motor, and problem-solving ( ORtotal ASQ: 1.14(1.05, 1.25), ORgross-motor: 1.22(1.10, 1.36), ORfine-motor: 1.19(1.07, 1.31), ORproblem-solving: 1.11(1.01, 1.23)). After sex-stratified analyses, pregnancy-average BPF concentration was associated with an increased risk of neurodevelopmental delays in the gross-motor (ORgross-motor:1.30(1.12, 1.51)) and fine-motor (ORfine-motor: 1.22(1.06, 1.40)) domains in boys. In the nested case-control study, placental estradiol mediated 16.6% (95%CI: 4.4%, 35.0%) of the effects of prenatal BPF exposure on developmental delay. CONCLUSIONS: Our study supports an inverse relationship between prenatal BPF exposure and child neurodevelopment in infancy, particularly in boys. Decreased placental estradiol may be an underlying biological pathway linking prenatal BPF exposure to neurodevelopmental delay in offspring.

[Identification and expression analysis of whole gene family of Isatis indigotica 4-coumarate: CoA ligase].

The 4-coumarate: CoA ligase(4CL) is a key enzyme in the upstream pathway of phenylpropanoids such as flavonoids, soluble phenolic esters, lignans, and lignins in plants. In this study, 13 4CL family members of Arabidopsis thaliana were used as reference sequences to identify the 4CL gene family candidate members of Isatis indigotica from the reported I. indigotica genome. Further bioinformatics analysis and analysis of the expression pattern of 4CL genes and the accumulation pattern of flavonoids were carried out. Thirteen 4CL genes were obtained, named Ii4CL1-Ii4CL13, which were distributed on chromosomes 1, 2, 3, 4, and 6. The analysis of the gene structure and conserved structural domains revealed the intron number of I. indigotica 4CL genes was between 1 and 12 and the protein structural domains were highly conserved. Cis-acting element analysis showed that there were multiple response elements in the promoter sequence of I. indigotica 4CL gene family, and jasmonic acid had the largest number of reaction elements. The collinearity analysis showed that there was a close relationship between the 4CL gene family members of I. indigotica and A. thaliana. As revealed by qPCR results, the expression analysis of the 4CL gene family showed that 10 4CL genes had higher expression levels in the aboveground part of I. indigotica. The content assay of flavonoids in different parts of I. indigotica showed that flavonoids were mainly accumulated in the aboveground part of plants. This study provides a basis for further investigating the roles of the 4CL gene family involved in the biosynthesis of flavonoids in I. indigotica.

Gerhardtite as a Precursor to an Efficient CO-to-Acetate Electroreduction Catalyst.

Carbon-carbon coupling electrochemistry on a conventional copper (Cu) catalyst still undergoes low selectivity among many different multicarbon (C2+) chemicals, posing a grand challenge to achieve a single C2+ product. Here, we demonstrate a laser irradiation synthesis of a gerhardtite mineral, Cu2(OH)3NO3, as a catalyst precursor to make a Cu catalyst with abundant stacking faults under reducing conditions. Such structural perturbation modulates electronic microenvironments of Cu, leading to improved d-electron back-donation to the antibonding orbital of *CO intermediates and thus strengthening *CO adsorption. With increased *CO coverage on the defect-rich Cu, we report an acetate selectivity of 56 ± 2% (compared to 31 ± 1% for conventional Cu) and a partial current density of 222 ± 7 mA per square centimeter in CO electroreduction. When run at 400 mA per square centimeter for 40 h in a flow reactor, this catalyst produces 68.3 mmol of acetate throughout. This work highlights the value of a Cu-containing mineral phase in accessing suitable structures for improved selectivity to a single desired C2+ product.

Single-cell analysis of ploidy and the transcriptome reveals functional and spatial divergency in murine megakaryopoiesis.

Megakaryocytes (MKs), the platelet progenitor cells, play important roles in hematopoietic stem cell (HSC) maintenance and immunity. However, it is not known whether these diverse programs are executed by a single population or by distinct subsets of cells. Here, we manually isolated primary CD41+ MKs from the bone marrow (BM) of mice and human donors based on ploidy (2N-32N) and performed single-cell RNA sequencing analysis. We found that cellular heterogeneity existed within 3 distinct subpopulations that possess gene signatures related to platelet generation, HSC niche interaction, and inflammatory responses. In situ immunostaining of mouse BM demonstrated that platelet generation and the HSC niche-related MKs were in close physical proximity to blood vessels and HSCs, respectively. Proplatelets, which could give rise to platelets under blood shear forces, were predominantly formed on a platelet generation subset. Remarkably, the inflammatory responses subpopulation, consisting generally of low-ploidy LSP1+ and CD53+ MKs (≤8N), represented ∼5% of total MKs in the BM. These MKs could specifically respond to pathogenic infections in mice. Rapid expansion of this population was accompanied by strong upregulation of a preexisting PU.1- and IRF-8-associated monocytic-like transcriptional program involved in pathogen recognition and clearance as well as antigen presentation. Consistently, isolated primary CD53+ cells were capable of engulfing and digesting bacteria and stimulating T cells in vitro. Together, our findings uncover new molecular, spatial, and functional heterogeneity within MKs in vivo and demonstrate the existence of a specialized MK subpopulation that may act as a new type of immune cell.

Role of ROS-mediated PERK/ATF4 signaling activation in extracorporeal tube formation injury of human umbilical vein endothelial cells induced by cooking oil fume PM2.5 exposure.

Cooking oil fume-derived PM2.5 (COF-PM2.5) is a major source of indoor air contamination in China, which has been demonstrated to be a hazard factor of cardiovascular and cerebrovascular diseases. This study aimed to investigate the role of ROS-mediated PERK/ATF4 signaling activation in COF-PM2.5-inhibited extracorporeal tube formation in human umbilical vein endothelial cells (HUVECs). HUVECs were treated with 100 µg/mL COF-PM2.5 at different times, with or without 100 nM PERK activity inhibitor GSK2606414 (GSK) or 200 µM antioxidant N-acetylcysteine (NAC) pretreatment. Our results showed that COF-PM2.5 exposure can inhibit extracorporeal tube formation and down-regulate VEGFR2 expression in HUVECs. Furthermore, our data indicated that COF-PM2.5 exposure can activate the PERK/ATF4 signaling in HUVECs. Mechanistically, pretreatment with GSK interdicted PERK/ATF4 signaling, thereby reversing COF-PM2.5-downregulated VEGFR2 protein expression in HUVECs. Furthermore, NAC reversed VEGFR2 expression downregulated induced by COF-PM2.5 by inhibiting the upregulation of intracellular ROS levels and PERK/ATF4 signaling in HUVECs. As above, COF-PM2.5 exposure could induce ROS release from HUVECs, which in turn activate the endoplasmic reticulum PERK/ATF4 signaling and inhibit tube formation of HUVECs.

Association of dietary total antioxidant capacity with all-cause and cardiovascular mortality in patients with chronic kidney disease: based on two retrospective cohort studies of NHANES.

BACKGROUND: The relationship between dietary total antioxidant capacity (DTAC) and death risk among CKD populations remains unclear. METHODS: Based on vitamin C equivalent antioxidant capacity (VCEAC) and the component dietary antioxidant index (CDAI) indices, we analyzed two cohorts to investigate the association of DTAC with all-cause and CVD mortality in CKD patients using data from National Health and Nutrition Examination Survey (2007-2018). VCEAC (n = 6330) and CDAI (n = 6300) cohorts with mortality follow-up data available through 2018 were included. Cox models with restricted cubic splines was used to model the nonlinear association between VCEAC/CDAI and outcomes in CKD patients. RESULTS: Our results showed L-shaped associations of DTAC with all-cause mortality among individuals with CKD stages 1-2 in both cohorts. Compared to the lowest quartile, higher dietary total antioxidant intake was associated with lower all-cause mortality risks among CKD stages 1-2 after adjustment for covariates, with HRs (95%CI) of 1.00, 0.91 (0.71,1.17), 0.69 (0.53,0.90), and 0.70 (0.54,0.91) in VCEAC, and similar respective estimate trends in CDAI. After sensitivity and subgroup analyses, there were no benefits for patients with stage 3-5 CKD or albuminuria. Mediation analysis revealed that the proportions mediated in both cohorts were less consistent. CONCLUSIONS: Moderate dietary total antioxidants intake has potential benefits for early-stage CKD patients. However, further evidence is needed to confirm whether patients with worsening CKD can benefit in the long term.

Association of carbohydrate intake from different sources with all-cause and cardiovascular mortality among chronic kidney disease populations: assessment of 1999-2018 National Health and Nutrition Examination Survey participation.

This study analysed the data from the NHANES (1999-2018) to examine how different sources of carbohydrate intake affected the all-cause and cardiovascular mortality of 11,302 chronic kidney disease (CKD) patients. The data were adjusted for other factors using various methods. The results showed that CKD patients (stages 1-2 and 3-5) who consumed more carbohydrates from whole grains, fruits, vegetables and less carbohydrates from fruit juice or sauces had lower mortality rates. Replacing fat intake with carbohydrates from whole grains (HR = 0.86[0.78-0.95]), fruits (raw) (HR = 0.79[0.70-0.88]) and non-starchy vegetables (HR = 0.82[0.70-0.96]), but not protein intake, was linked to lower all-cause mortality. The fibre content in carbohydrates might partly account for the benefits of selected carbohydrate intake. This study provided practical recommendations for optimising the carbohydrate sources in CKD patients.

[Application of microneedle-assisted percutaneous drug delivery system in treatment of rheumatoid arthritis:a review].

Rheumatoid arthritis(RA) is a chronic degenerative joint disease characterized by inflammation. Due to the complex causes, no specific therapy is available. Non-steroidal anti-inflammatory agents and corticosteroids are often used(long-term, oral/injection) to interfere with related pathways for reducing inflammatory response and delaying the progression of RA, which, however, induce many side effects. Microneedle, an emerging transdermal drug delivery system, is painless and less invasive and improves drug permeability. Thus, it is widely used in the treatment of RA and is expected to be a new strategy in clinical treatment. This paper summarized the application of microneedles in the treatment of RA, providing a reference for the development of new microneedles and the expansion of its clinical application.

[Cloning and catalytic analysis of Isatis indigotica chalcone isomerase in vitro].

Chalcone isomerase is a key rate-limiting enzyme in the biosynthesis of flavonoids in higher plants, which determines the production of flavonoids in plants. In this study, RNA was extracted from different parts of Isatis indigotica and reverse-transcribed into cDNA. Specific primers with enzyme restriction sites were designed, and a chalcone isomerase gene was cloned from I. indigotica, named IiCHI. IiCHI was 756 bp in length, containing a complete open reading frame and encoding 251 amino acids. Homology analysis showed that IiCHI was closely related to CHI protein of Arabidopsis thaliana and had typical active sites of chalcone isomerase. Phylogenetic tree analysis showed that IiCHI was classified into type Ⅰ CHI clade. Recombinant prokaryotic expression vector pET28a-IiCHI was constructed and purified to obtain IiCHI recombinant protein. In vitro enzymatic analysis showed that the IiCHI protein could convert naringenin chalcone into naringenin, but could not catalyze the production of liquiritigenin by isoliquiritigenin. The results of real-time quantitative polymerase chain reaction(qPCR) showed that the expression level of IiCHI in the aboveground parts was higher than that in the underground parts and the expression level was the highest in the flowers of the aboveground parts, followed by leaves and stems, and no expression was observed in the roots and rhizomes of the underground parts. This study has confirmed the function of chalcone isomerase in I. indigotica and provided references for the biosynthesis of flavonoid components.

[Medicinal plant resources in Inner Mongolia autonomous region of China and Mongolia: a comparative study].

Inner Mongolia autonomous region of China and Mongolia are the primary regions where Chinese and Mongolian medicine and its medicinal plant resources are distributed. In this study, 133 families, 586 genera, and 1 497 species of medicinal plants in Inner Mongolia as well as 62 families, 261 genera, and 467 species of medicinal plants in Mongolia were collected through field investigation, specimen collection and identification, and literature research. And the species, geographic distribution, and influencing factors of the above medicinal plants were analyzed. The results revealed that there were more plant species utilized for medicinal reasons in Inner Mongolia than in Mongolia. Hotspots emerged in Hulunbuir, Chifeng, and Tongliao of Inner Mongolia, while there were several hotspots in Eastern province, Sukhbaatar province, Gobi Altai province, Bayankhongor province, Middle Gobi province, Kobdo province, South Gobi province, and Central province of Mongolia. The interplay of elevation and climate made a non-significant overall contribution to the diversity of plant types in Inner Mongolia and Mongolia. The contribution of each factor increased significantly when the vegetation types of Inner Mongolia and Mongolia were broadly divided into forest, grassland and desert. Thus, the distribution of medicinal plant resources and vegetation cover were jointly influenced by a variety of natural factors such as topography, climate and interactions between species, and these factors contributed to and constrained each other. This study provided reference for sustainable development and rational exploitation of medicinal plant resources in future.