Efficient Production of Flavonoid Glucuronides in Escherichia coli Using Flavonoid O-Glucuronosyltransferases Characterized from Marchantia polymorpha.

As a model liverwort, Marchantia polymorpha contains various flavone glucuronides with cardiovascular-promoting effects and anti-inflammatory properties. However, the related glucuronosyltransferases have not yet been reported. In this study, two bifunctional UDP-glucuronic acid/UDP-glucose:flavonoid glucuronosyltransferases/glucosyltransferases, MpUGT742A1 and MpUGT736B1, were identified from M. polymorpha. Extensive enzymatic assays found that MpUGT742A1 and MpUGT736B1 exhibited efficient glucuronidation activity for flavones, flavonols, and flavanones and showed promiscuous regioselectivity at positions 3, 6, 7, 3', and 4'. These enzymes catalyzed the production of a variety of flavonoid glucuronides with medicinal value, including apigenin-7-O-glucuronide and scutellarein-7-O-glucuronide. With the use of MpUGT736B1, apigenin-4'-O-glucuronide and apigenin-7,4'-di-O-glucuronide were prepared by scaled-up enzymatic catalysis and structurally identified by NMR spectroscopy. MpUGT742A1 also displayed glucosyltransferase activity on the 7-OH position of the flavanones using UDP-glucose as the sugar donor. Furthermore, we constructed four recombinant strains by combining the pathway for increasing the UDP-glucuronic acid supply with the two novel UGTs MpUGT742A1 and MpUGT736B1. When apigenin was used as a substrate, the extracellular apigenin-4'-O-glucuronide and apigenin-7,4'-di-O-glucuronide production obtained from the Escherichia coli strain BB2 reached 598 and 81 mg/L, respectively. Our study provides new candidate genes and strategies for the biosynthesis of flavonoid glucuronides.

Atorvastatin-induced intracerebral hemorrhage is inhibited by berberine in zebrafish.

Intracerebral hemorrhage (ICH), for which there are currently no effective preventive or treatment methods, has a very high fatality rate. Statins, such as atorvastatin (ATV), are the first-line drugs for regulating blood lipids and treating hyperlipidemia-related cardiovascular diseases. However, ATV-associated ICH has been reported, although its incidence is rare. In this study, we aimed to investigate the protective action and mechanisms of berberine (BBR) against ATV-induced brain hemorrhage. We established an ICH model in zebrafish induced by ATV (2 µM) and demonstrated the effects of BBR (10, 50, and 100 µM) on ICH via protecting the vascular network using hemocyte staining and three transgenic zebrafish. BBR was found to reduce brain inflammation and locomotion injury in ICH-zebrafish. Mechanism research showed that ATV increased the levels of VE-cadherin and occludin proteins but disturbed their localization at the cell membrane by abnormal phosphorylation, which decreased the number of intercellular junctions between vascular endothelial cells (VECs), disrupting the integrity of vascular walls. BBR reversed the effects of ATV by promoting autophagic degradation of phosphorylated VE-cadherin and occludin in ATV-induced VECs examined by co-immunoprecipitation (co-IP). These findings provide crucial insights into understanding the BBR mechanisms involved in the maintenance of vascular integrity and in mitigating adverse reactions to ATV.

Interaction of PKR with STCS1: an indispensable step in the biosynthesis of lunularic acid in Marchantia polymorpha.

Unlike bibenzyls derived from the vascular plants, lunularic acid (LA), a key precursor for macrocyclic bisbibenzyl synthesis in nonvascular liverworts, exhibits the absence of one hydroxy group within the A ring. It was hypothesized that both polyketide reductase (PKR) and stilbenecarboxylate synthase 1 (STCS1) were involved in the LA biosynthesis, but the underlined mechanisms have not been clarified. This study used bioinformatics analysis with molecular, biochemical and physiological approaches to characterize STCS1s and PKRs involved in the biosynthesis of LA. The results indicated that MpSTCS1s from Marchantia polymorpha catalyzed both C2→C7 aldol-type and C6→C1 Claisen-type cyclization using dihydro-p-coumaroyl-coenzyme A (CoA) and malonyl-CoA as substrates to yield a C6-C2-C6 skeleton of dihydro-resveratrol following decarboxylation and the C6-C3-C6 type of phloretin in vitro. The protein-protein interaction of PKRs with STCS1 (PPI-PS) was revealed and proved essential for LA accumulation when transiently co-expressed in Nicotiana benthamiana. Moreover, replacement of the active domain of STCS1 with an 18-amino-acid fragment from the chalcone synthase led to the PPI-PS greatly decreasing and diminishing the formation of LA. The replacement also increased the chalcone formation in STCS1s. Our results highlight a previously unrecognized PPI in planta that is indispensable for the formation of LA.

Identification of a flavonoid C-glycosyltransferase from fern species Stenoloma chusanum and the application in synthesizing flavonoid C-glycosides in Escherichia coli.

BACKGROUND: Flavonoid C-glycosides have many beneficial effects and are widely used in food and medicine. However, plants contain a limited number of flavonoid C-glycosides, and it is challenging to create these substances chemically. RESULTS: To screen more robust C-glycosyltransferases (CGTs) for the biosynthesis of flavonoid C-glycosides, one CGT enzyme from Stenoloma chusanum (ScCGT1) was characterized. Biochemical analyses revealed that ScCGT1 showed the C-glycosylation activity for phloretin, 2-hydroxynaringenin, and 2-hydroxyeriodictyol. Structure modeling and mutagenesis experiments indicated that the glycosylation of ScCGT1 may be initiated by the synergistic action of conserved residue His26 and Asp14. The P164T mutation increased C-glycosylation activity by forming a hydrogen bond with the sugar donor. Furthermore, when using phloretin as a substrate, the extracellular nothofagin production obtained from the Escherichia coli strain ScCGT1-P164T reached 38 mg/L, which was 2.3-fold higher than that of the wild-type strain. Finally, it is proved that the coupling catalysis of CjFNS I/F2H and ScCGT1-P164T could convert naringenin into vitexin and isovitexin. CONCLUSION: This is the first time that C-glycosyltransferase has been characterized from fern species and provides a candidate gene and strategy for the efficient production of bioactive C-glycosides using enzyme catalysis and metabolic engineering.

Mirabegron Ameliorated Atherosclerosis of ApoE-/- Mice in Chronic Intermittent Hypoxia but Not in Normoxia.

PURPOSE: It has been established that obstructive sleep apnea (OSA) is an independent risk factor for atherosclerosis. Chronic intermittent hypoxia (CIH) activates sympathoadrenal system and upregulates ß3 adrenergic receptor (ß3 AR). However, the effect of selective ß3 AR agonist mirabegron in CIH-induced atherosclerosis remains unknown. METHODS: We generated a CIH-induced atherosclerosis model through exposing ApoE-/- mice to CIH (8 h per day, cyclic inspiratory oxygen fraction 5-21%, 60-s cycle) for 6 weeks after 4-week high-fat dieting and investigated the effects of mirabegron, a selective ß3 AR agonist, on CIH-induced atherosclerosis. The coronary endarterectomy (CE) specimens from coronary artery disease patients with OSA and without OSA were collected. RESULTS: The expression of ß3 AR was significantly elevated in CIH-induced atherosclerosis model. Furthermore, treatment with mirabegron (10mg/kg per day by oral administration for 6 weeks) ameliorated atherosclerosis in ApoE-/- mice in CIH but not in normoxia. Mechanistically, mirabegron activated ß3 AR and ameliorated intraplaque oxidative stress by suppressing p22phox expression and reactive oxygen species (ROS) level. In addition, in human CE specimens, ß3 AR was also upregulated associated with increased p22phox expression and ROS level both in the lumen and in the plaque of coronary artery in OSA subjects. CONCLUSION: This study first demonstrated that mirabegron impeded the progression of CIH-induced atherosclerosis, at least in part, via ß3 AR-mediated oxidative stress, suggesting a promising therapeutic strategy for protecting against atherosclerosis induced by CIH.

[Preparation of microemulsion gel loading enriched ingredients of Epimedii Folium and its pharmacodynamics evaluation].

On the basis of previous studies, this study prepared and evaluated microemulsion gel loading enriched ingredients of Epimedii Folium and investigated its protective effect against peripheral nervous system damage caused by chemotherapeutics. The preparation method and the type and dosage of the matrix were investigated from rheology, preparation difficulty, and drug loading. Then the optimal prescription was determined and the microemulsion gel loading enriched ingredients of Epimedii Folium was prepared. The in vitro release and transdermal behaviors of the gel were investigated in the Franz diffusion cell with epimedin A1,A,B,C, and icariin as evaluation indicators. The oxaliplatin-induced peripheral neuropathy(OIPN) model was established in Wistar rats. The protective effect of the microemulsion gel loading enriched ingredients of Epimedii Folium against peripheral nervous system damage caused by chemotherapeutics was evaluated by behavioral measurement after drug administration and histopathological examination of dorsal root ganglia and sciatic nerve. The preparation process of the microemulsion gel loading enriched ingredients of Epimedii Folium was stable, and the release of the five components was consistent with the Hixson-Crowell cube root law. Behavioral indicators intuitively showed that the drug could effectively relieve mechanical allodynia caused by oxaliplatin. The histopathological examination showed that the drug can improve neuron damage in the dorsal root ganglia, axon degeneration, and demyelination caused by oxaliplatin. Therefore, the preparation process of the microemulsion gel loading enriched ingredients of Epimedii Folium is feasible, which can achieve stable drug release. It has a certain therapeutic effect on chemotherapy-induced peripheral neuropathy(CIPN).

Salicylic acid regulates adventitious root formation via competitive inhibition of the auxin conjugation enzyme CsGH3.5 in cucumber hypocotyls.

MAIN CONCLUSION: Exogenous SA treatment at appropriate concentrations promotes adventitious root formation in cucumber hypocotyls, via competitive inhibiting the IAA-Asp synthetase activity of CsGH3.5, and increasing the local free IAA level. Adventitious root formation is critical for the cutting propagation of horticultural plants. Indole-3-acetic acid (IAA) has been shown to play a central role in regulating this process, while for salicylic acid (SA), its exact effects and regulatory mechanism have not been elucidated. In this study, we showed that exogenous SA treatment at the concentrations of both 50 and 100 µM promoted adventitious root formation at the base of the hypocotyl of cucumber seedlings. At these concentrations, SA could induce the expression of CYCLIN and Cyclin-dependent Kinase (CDK) genes during adventitious rooting. IAA was shown to be involved in SA-induced adventitious root formation in cucumber hypocotyls. Exposure to exogenous SA led to a slight increase in the free IAA content, and pre-treatment with the auxin transport inhibitor 1-naphthylphthalamic acid (NPA) almost completely abolished the inducible effects of SA on adventitious root number. SA-induced IAA accumulation was also associated with the enhanced expression of Gretchen Hagen3.5 (CsGH3.5). The in vitro enzymatic assay indicated that CsGH3.5 has both IAA- and SA-amido synthetase activity and prefers aspartate (Asp) as the amino acid conjugate. The Asp concentration dictated the functional activity of CsGH3.5 on IAA. Both affinity and catalytic efficiency (Kcat/Km) increased when the Asp concentration increased from 0.3 to 1 mM. In contrast, CsGH3.5 showed equal catalytic efficiency for SA at low and high Asp concentrations. Furthermore, SA functioned as a competitive inhibitor of the IAA-Asp synthetase activity of CsGH3.5. During adventitious formation, SA application indeed repressed the IAA-Asp levels in the rooting zone. These data show that SA plays an inducible role in adventitious root formation in cucumber through competitive inhibition of the auxin conjugation enzyme CsGH3.5. SA reduces the IAA conjugate levels, thereby increasing the local free IAA level and ultimately enhancing adventitious root formation.

Down-regulation of lncRNA CASC9 aggravates sepsis-induced acute lung injury by regulating miR-195-5p/PDK4 axis.

BACKGROUND: Long non-coding RNA (lncRNA) cancer susceptibility candidate 9 (CASC9) is reported to be linked to cancers. This research aims to explore the role and possible mechanism of CASC9 in lung injury induced by sepsis. METHODS: Lipopolysaccharide (LPS) induced human small airway epithelial cells (HSAECs) were established in vitro to mimic sepsis-induced lung injury. The effects of CASC9 and miR-195-5p on HSAECs viability were studied by CCK-8 assay. Interactions between CASC9 and miR-195-5p were determined by bioinformatics analysis, RT-PCR, dual luciferase reporter assay, and RNA immunoprecipitation assay. Pyruvate dehydrogenase kinase 4 (PDK4) and apoptosis-related molecules including Bcl2 and Bad were detected by western blot. Additionally, sepsis-induced lung injury model in rats was established by intraperitoneal injection of LPS in vivo to validate the demonstrations of in vitro studies. RESULTS: CASC9 was markedly down-regulated while miR-195-5p was significantly up-regulated in HSAECs treated by LPS and lung tissues of rats with sepsis. CASC9 interacted with miR-195-5p, and negatively regulated its expression level. Overexpression of CASC9 or transfection of miR-195-5p inhibitors significantly promoted the viability of HSAECs. The transfection of miR-195-5p mimics effected oppositely. For mechanism, miR-195-5p targeted the 3'UTR of pyruvate dehydrogenase kinase 4 (PDK4) gene and depressed the protein level, and PDK4 was regulated indirectly by CASC9. Restoration of CASC9 in the lung tissues of rats with sepsis ameliorated lung injury. CONCLUSION: CASC9 protects lung epithelial cells from sepsis-induced injury via regulating miR-195-5p/PDK4 axis.

[Effect and mechanism of essential oil from Zanthoxylum bungeanum in microemulsion gel preparation on percutaneous delivery of complex components].

This study aimed to investigate the transdermal enhancing effect of essential oil from Zanthoxylum bungeanum(Z. bungeanum oil) in microemulsion gel(ZO-ME-gel) on permeation of different components,and reveal the transdermal enhancing mechanism of ZO-ME-gel. A series of components with different log P values were selected as model drugs and encapsulated in ZO-ME-gel to simplify and characterize the complex components of traditional Chinese medicine. The transdermal behavior of the model drugs was further examined using the improved Franz diffusion cell method. Then attenuated total reflection Fourier transform infrared spectroscopy(ATR-FTIR),differential scanning calorimetry(DSC) studies and hematoxylin-eosin(HE) staining were used to investigate the effects of Z. bungeanum oil and ZO-ME-gel on keratin,intercellular lipids and microstructure of the stratum corneum(SC). The results showed that Z. bungeanum oil and ZO-ME-gel had a good transdermal enhancing effect on both hydrophilic and lipophilic drugs,and the best effect was achieved when log P value was-0. 5. The transdermal enhancing mechanism of Z. bungeanum oil and ZO-ME-gel was related to affecting the order of the SC lipids,changing lipid fluidity and protein conformation,and disrupting the integrity of the SC structure. 5% Z. bungeanum oil had greater transdermal enhancing effect and destruction of SC structure than ZO-ME-gel. These results suggested that Z. bungeanum oil loaded in microemulsion gel still had a good transdermal enhancing effect although the effect was not as great as Z. bungeanum oil itself,in addition,ZO-ME-gel was less irritating to the skin and safer to use,which had a guiding role in the development and clinical application of Z. bungeanum oil-containing traditional Chinese medicine topical preparations.

[Regularity of traditional Chinese medicine prescriptions for same treatment for cardiovascular and cerebrovascular diseases].

To explore the regularity of traditional Chinese medicine(TCM) prescriptions for cardio-cerebrovascular diseases,the core drug groups with common therapeutic effects on cerebrovascular diseases represented by stroke and cardiovascular diseases represented by coronary artery disease were extracted,and their consistency and difference in the treatment of different diseases were analyzed.A total of 388 Chinese patent medicines were collected for the treatment of cerebrovascular diseases,cardiovascular diseases and cardio-cerebrovascular diseases.The dominant and recessive patterns of Chinese patent medicines in clinical use were found by "frequency analysis","compatibility analysis" and "network analysis" respectively.According to the findings of the three parts,Salviae Miltiorrhizae Radix et Rhizoma,Chuanxiong Rhizoma,Carthami Flos and Astragali Radix have a high frequency of use in the treatment of brain disease,heart disease and both,with frequent combined medication.Data mining confirmed the core drug combinations for the treatment of cerebral and cardiac vascular diseases,so as to reveal the similarities and differences in the drug use of Chinese medicine for these diseases,and provide a basis for the rational use of traditional Chinese medicine in clinical practice.This analysis also defines a new direction for the future development of prescription combinations for different indications of cerebral and cardiac diseases.

A bHLH Transcription Factor Regulates Bisbibenzyl Biosynthesis in the Liverwort Plagiochasma appendiculatum.

Liverworts, a section of the bryophyte plants which pioneered the colonization of terrestrial habitats, produce cyclic bisbibenzyls as secondary metabolites. These compounds are generated via the phenylpropanoid pathway, similar to flavonoid biosynthesis, for which basic helix-loop-helix (bHLH) transcription factors have been identified as one of the important regulators in higher plants. Here, a bHLH gene homolog (PabHLH) was isolated from the liverwort species Plagiochasma appendiculatum and its contribution to bisbibenzyl biosynthesis was explored. Variation in the abundance of PabHLH transcript mirrored that of tissue bisbibenzyl content in three different liverwort tissues. A phylogenetic analysis based on the bHLH domain sequence suggested that the gene encodes a member of bHLH subgroup IIIf, which clusters proteins involved in flavonoid synthesis. The gene's transient expression in onion epidermal cells implied that its product localized to the nucleus, and a transactivation assays in yeast showed that it was able to activate transcription. In both callus and thallus, the overexpression of PabHLH boosted bisbibenzyl accumulation, while also up-regulating PaPAL, Pa4CL1, PaSTCS1 and two genes encoding P450 cytochromes, and its RNA interference (RNAi)-induced suppression down-regulated the same set of genes and reduced the accumulation of bisbibenzyls. The abundance of PaCHS and PaFNSI transcript was related to flavonoid accumulation in transgenic thallus. PabHLH represents a candidate for the metabolic engineering of bisbibenzyl content.

Molecular Diversity of Alkenal Double Bond Reductases in the Liverwort Marchantia paleacea.

Alkenal double bond reductases (DBRs), capable of catalyzing the NADPH-dependent reduction of the α,ß-unsaturated double bond, play key roles in the detoxication of alkenal carbonyls. Here, the isolation and characterization of two DBRs encoded by the liverwort species Marchantia paleacea are described. The two DBRs share a relatively low similarity, and phylogenetic analysis indicated that MpMDBRL is more closely related to microbial DBRs than to other plant DBRs, while MpDBR shares common ancestry with typical plant DBRs. Both DBR proteins exhibited hydrogenation ability towards hydroxycinnamyl aldehydes; however, their temperature optimums were strikingly different. MpMDBRL demonstrated slightly weaker catalytic efficiency compared to MpDBR, and the structural models of their active binding sites to the substrate may provide a parsimonious explanation. Furthermore, both DBRs significantly responded to phytohormone treatment. In conclusion, M. paleacea produces two distinct types of functional DBRs, both of which participate in the protection against environmental stress in liverwort. The presence of a microbial type of DBR in a plant is herein reported for the first time.

Cloning and Functional Characterization of Two 4-Coumarate: CoA Ligase Genes from Selaginella moellendorffii.

Selaginella is an extant lycopodiophyte genus, which is representative of an ancient lineage of tracheophytes. The important evolutionary status makes it a valuable resource for the study of metabolic evolution in vascular plants. 4-coumarate: CoA ligase (4CL) is the pivotal enzyme that controls the flow of carbon through the phenylpropanoid metabolic pathway into the specific lignin, flavonoid, and wall-bound phenolics biosynthesis pathways. Although 4CLs have been extensively characterized in other vascular plants, little is known of their functions in Selaginella. Here, we isolated two 4CL genes (Sm4CL1 and Sm4CL2) from Selaginella moellendorffii. Based on the enzymatic activities of the recombinant proteins, both of these genes encoded bona fide 4CLs. The 4CL isoforms in S. moellendorffii have different activities: Sm4CL2 was more active than Sm4CL1. The enzymatic properties and gene expression patterns indicated that the 4CL genes have been conserved in the evolution of vascular plants.

Healing High-Loading Sulfur Electrodes with Unprecedented Long Cycling Life: Spatial Heterogeneity Control.

Self-healing capability helps biological systems to maintain their survivability and extend their lifespan. Similarly, self-healing is also beneficial to next-generation secondary batteries because high-capacity electrode materials, especially the cathodes such as oxygen or sulfur, suffer from shortened cycle lives resulting from irreversible and unstable phase transfer. Herein, by mimicking a biological self-healing process, fibrinolysis, we introduced an extrinsic healing agent, polysulfide, to enable the stable operation of sulfur microparticle (SMiP) cathodes. An optimized capacity (∼3.7 mAh cm-2) with almost no decay after 2000 cycles at a high sulfur loading of 5.6 mg(S) cm-2 was attained. The inert SMiP is activated by the solubilization effect of polysulfides whereas the unstable phase transfer is mediated by mitigated spatial heterogeneity of polysulfides, which induces uniform nucleation and growth of solid compounds. The comprehensive understanding of the healing process, as well as of the spatial heterogeneity, could further guide the design of novel healing agents (e.g., lithium iodine) toward high-performance rechargeable batteries.

Cloning and functional characterization of a phenolic acid decarboxylase from the liverwort Conocephalum japonicum.

Some commercially important vinyl derivatives are produced by the decarboxylation of phenolic acids. Enzymatically, this process can be achieved by phenolic acid decarboxylases (PADs), which are able to act on phenolic acid substrates such as ferulic and p-coumaric acid. Although many microbial PADs have been characterized, little is known regarding their plant homologs. Transcriptome sequencing in the liverworts has identified seven putative PADs, which share a measure of sequence identity with microbial PADs, but are typically much longer proteins. Here, a PAD-encoding gene was isolated from the liverwort species Conocephalum japonicum. The 1197 nt CjPAD cDNA sequence was predicted to be translated into a 398 residue protein. When the gene was heterologously expressed in Escherichia coli, its product exhibited a high level of PAD activity when provided with either p-coumaric or ferulic acid as substrate, along with the conversion of caffeic acid and sinapic acid to their corresponding decarboxylated products. Both N- and C-terminal truncation derivatives were non-functional. The transient expression in tobacco of a GFP/CjPAD fusion gene demonstrated that the CjPAD protein is expressed in the cytoplasm. It is first time a PAD was characterized from plants and the present investigation provided a candidate gene for catalyzing the formation of volatile phenols.

Cognitive Training in Older Adults with Mild Cognitive Impairment.

OBJECTIVE: We investigated the feasibility and efficacy of cognitive training for older adults in rural settings and with low education levels, who have mild cognitive impairment (MCI). METHODS: Forty-five older adults (ages >65 years) with MCI were assigned to treatment or control groups, at a 2:1 ratio. Cognitive training occurred in the treatment group for 2 months. The cognitive abilities of the participants were assessed at pre-training, metaphase, and post-training time points, using the Mini-Mental State Examination (MMSE), Montreal Cognitive Assessment (MoCA), Loewenstein Occupational Therapy Cognitive Assessment (LOTCA), and Hamilton Depression Scale (HAM-D). RESULTS: Following training, cognitive abilities improved in the treatment group, based on the total scores of all 4 measures, as well as specifically on the MoCA and LOTCA. There were differences in the main effects of group and time point on some subscales, but these differences had little, if any, effect on the overall analyses. CONCLUSION: The present study demonstrated that cognitive training has beneficial effects on attention, language, orientation, visual perception, organization of visual movement, and logical questioning in patients with MCI. Furthermore, the observed effects are long-term changes.

Endogenous salicylic acid accumulation is required for chilling tolerance in cucumber (Cucumis sativus L.) seedlings.

Salicylic acid (SA) is an important plant hormone, and its exogenous application can induce tolerance to multiple environmental stresses in plants. In this study, we examine the potential involvement of endogenous SA in response to chilling in cucumber (Cucumis sativus L.) seedlings. A low temperature of 8 °C induces a moderate increase in endogenous SA levels. Chilling stimulates the enzymatic activities and the expression of genes for phenylalanine ammonia-lyase (PAL) and benzoic acid-2-hydroxylase rather than isochorismate synthase. This indicates that the PAL enzymatic pathway contributes to chilling-induced SA production. Cucumber seedlings pretreated with SA biosynthesis inhibitors accumulate less endogenous SA and suffer more from chilling damage. The expression of cold-responsive genes is also repressed by SA inhibitors. The reduction in stress tolerance and in gene expression can be restored by the exogenous application of SA, confirming the critical roles of SA in chilling responses in cucumber seedlings. Furthermore, the inhibition of SA biosynthesis under chilling stress results in a prolonged and enhanced hydrogen peroxide (H2O2) accumulation. The application of exogenous SA and the chemical scavenger of H2O2 reduces the excess H2O2 and alleviates chilling injury. In contrast, the protective effects of SA are negated by foliar spraying with high concentrations of H2O2 and an inhibitor of the antioxidant enzyme. These results suggest that endogenous SA is required in response to chilling stress in cucumber seedlings, by modulating the expression of cold-responsive genes and the precise induction of cellular H2O2 levels.

Improved photoelectrical properties of n-ZnO/p-Si heterojunction by inserting an optimized thin Al2O3 buffer layer.

The n-ZnO/p-Si heterojunction with an ultrathin Al2O3 buffer layer was prepared by atomic layer deposition. X-ray diffraction revealed that the crystalline quality of (100)-oriented ZnO films was improved with an Al2O3 buffer layer. The n-ZnO/p-Si heterojunction with 5 nm inserted Al2O3 layer shows the best electrical characteristics, with a dark current of 0.5 µA at a reverse bias of -2 V and increasing the photo-to-dark current ratio effectively by 8 times. These results demonstrated that Al2O3 buffer layer with optimized thickness exhibits significant advantages in enhancing the crystal quality of ZnO film and improving the photoelectrical properties of n-ZnO/p-Si photodetectors.

[Management options of caesarean scar pregnancy].

Cesarean scar pregnancy is an uncommon ectopic gestation. Without timely and proper management, it may cause major bleeding, uterine rupture, and other life-threatening complications. The causes of this condition remain unclear, and no standardized management has been available, although some medical and surgical treatment modalities have been suggested. The main treatment objectives include preventing massive blood loss, preserving the uterus function, and maintain the women's health and quality of life. Current data do not support expectant management. After early diagnosis, single or combined medical and surgical treatment options should be provided to avoid uterine rupture and haemorrhage, so as to preserve the uterus and thus the fertility.

Molecular cloning and functional analysis of 4-coumarate: CoA ligases from Marchantia paleacea and their roles in lignin and flavanone biosynthesis.

Phenylpropanoids play important roles in plant physiology and the enzyme 4-coumarate: coenzyme A ligase (4CL) catalyzes the formation of thioesters. Despite extensive characterization in various plants, the functions of 4CLs in the liverwort Marchantia paleacea remain unknown. Here, four 4CLs from M. paleacea were isolated and functionally analyzed. Heterologous expression in Escherichia coli indicated the presence of different enzymatic activities in the four enzymes. Mp4CL1 and Mp4CL2 were able to convert caffeic, p-coumaric, cinnamic, ferulic, dihydro-p-coumaric, and 5-hydroxyferulic acids to their corresponding CoA esters, while Mp4CL3 and Mp4CL4 catalyzed none. Mp4CL1 transcription was induced when M. paleacea thalli were treated with methyl jasmonate (MeJA). The overexpression of Mp4CL1 increased the levels of lignin in transgenic Arabidopsis. In addition, we reconstructed the flavanone biosynthetic pathway in E. coli. The pathway comprised Mp4CL1, co-expressed with chalcone synthase (CHS) from different plant species, and the efficiency of biosynthesis was optimal when both the 4CL and CHS were obtained from the same species M. paleacea.