RESUMO
Plant JASMONATE ZIM-DOMAIN (JAZ) genes play crucial roles in regulating the biosynthesis of specialized metabolites and stressful responses. However, understanding of JAZs controlling these biological processes lags due to numerous JAZ copies. Here, we found that two leaf-specific CwJAZ4/9 genes from Curcuma wenyujin are strongly induced by methyl-jasmonate (MeJA) and negatively correlated with terpenoid biosynthesis. Yeast two-hybrid, luciferase complementation imaging and in vitro pull-down assays confirmed that CwJAZ4/9 proteins interact with CwMYC2 to form the CwJAZ4/9-CwMYC2 regulatory cascade. Furthermore, transgenic hairy roots showed that CwJAZ4/9 acts as repressors of MeJA-induced terpenoid biosynthesis by inhibiting the terpenoid pathway and jasmonate response, thus reducing terpenoid accumulation. In addition, we revealed that CwJAZ4/9 decreases salt sensitivity and sustains the growth of hairy roots under salt stress by suppressing the salt-mediated jasmonate responses. Transcriptome analysis for MeJA-mediated transgenic hairy root lines further confirmed that CwJAZ4/9 negatively regulates the terpenoid pathway genes and massively alters the expression of genes related to salt stress signaling and responses, and crosstalks of multiple phytohormones. Altogether, our results establish a genetic framework to understand how CwJAZ4/9 inhibits terpenoid biosynthesis and confers salt tolerance, which provides a potential strategy for producing high-value pharmaceutical terpenoids and improving resistant C. wenyujin varieties by a genetic approach.
Assuntos
Acetatos , Curcuma , Ciclopentanos , Regulação da Expressão Gênica de Plantas , Oxilipinas , Proteínas de Plantas , Tolerância ao Sal , Terpenos , Oxilipinas/metabolismo , Ciclopentanos/metabolismo , Tolerância ao Sal/genética , Proteínas de Plantas/metabolismo , Proteínas de Plantas/genética , Terpenos/metabolismo , Acetatos/farmacologia , Acetatos/metabolismo , Curcuma/metabolismo , Curcuma/genética , Plantas Geneticamente Modificadas , Reguladores de Crescimento de Plantas/metabolismo , Raízes de Plantas/metabolismo , Raízes de Plantas/genética , Raízes de Plantas/efeitos dos fármacosRESUMO
In yam (Dioscorea spp) species, bulbils at leaf axils are the most striking species-specific axillary structure and exhibit important ecological niches. Genetic regulation underlying bulbil growth remains largely unclear so far. Here, we characterize yam (Dioscorea alata L.) bulbil development using histological analysis, and perform full transcriptional profiling on key developmental stages together with phytohormone analyses. Using the stage-specific scoring algorithm, we have identified 3451 stage-specifically expressed genes that exhibit a tight link between major transcriptional changes and stages. Co-expressed gene clusters revealed an obvious over-representation of genes associated with cell division and expansion at the initiation stage of bulbils (T1). Transcriptional changes of hormone-related genes highly coincided with hormone levels, indicating that bulbil initiation and growth are coordinately controlled by multiple phytohormones. In particular, localized auxin is transiently required to trigger bulbil initiation, and be further depleted or exported from bulbils to promote growth by up-regulation of genes involved in auxinconjugation and efflux. The sharp increase in supply of sucrose and an enhanced trehalose-6-phophate pathway at T1 were observed, suggesting that sucrose probably functions as a key signal and promotes bulbil initiation. Analysis of the expression of transcription factors (TFs) predicated 149 TFs as stage-specifically expressed; several T1-specific TFs (from Aux/IAA, E2F, MYB, and bHLH families) have been shown to play key roles in triggering bulbil formation. Together, our work provides a crucial angle for in-depth understanding of the molecular programs underlying yam's unique bulbil development processes. Stage-specific gene sets can be queried to obtain key candidates regulating bulbil growth, serving as valuable resources for further functional research.
Assuntos
Dioscorea , Dioscorea/genética , Perfilação da Expressão Gênica , Regulação da Expressão Gênica , Ácidos Indolacéticos , Folhas de PlantaRESUMO
Plant-derived monoterpene indole alkaloids (MIAs) from Uncaria rhynchophylla (UR) have huge medicinal properties in treating Alzheimer's disease, Parkinson's disease, and depression. Although many bioactive UR-MIA products have been isolated as drugs, their biosynthetic pathway remains largely unexplored. In this study, untargeted metabolome identified 79 MIA features in UR tissues (leaf, branch stem, hook stem, and stem), of which 30 MIAs were differentially accumulated among different tissues. Short time series expression analysis captured 58 pathway genes and 12 hub regulators responsible for UR-MIA biosynthesis and regulation, which were strong links with main UR-MIA features. Coexpression networks further pointed to two strictosidine synthases (UrSTR1/5) that were coregulated with multiple MIA-related genes and highly correlated with UR-MIA features (r > 0.7, P < 0.005). Both UrSTR1/5 catalyzed the formation of strictosidine with tryptamine and secologanin as substrates, highlighting the importance of key residues (UrSTR1: Glu309, Tyr155; UrSTR5: Glu295, Tyr141). Further, overexpression of UrSTR1/5 in UR hairy roots constitutively increased the biosynthesis of bioactive UR-MIAs (rhynchophylline, isorhynchophylline, corynoxeine, etc), whereas RNAi of UrSTR1/5 significantly decreased UR-MIA biosynthesis. Collectively, our work not only provides candidates for reconstituting the biosynthesis of bioactive UR-MIAs in heterologous hosts but also highlights a powerful strategy for mining natural product biosynthesis in medicinal plants.
Assuntos
Alcaloides , Alcaloides de Vinca , Monoterpenos/metabolismo , Alcaloides Indólicos/metabolismo , Alcaloides de Vinca/química , Alcaloides de Vinca/metabolismoRESUMO
Abnormal blood pressure is common in critically ill stroke patients. However, the association between mean arterial pressure (MAP) and mortality of critically ill stroke patients remains unclear. We extracted eligible acute stroke patients from the MIMIC-III database. The patients were divided into three groups: a low MAP group (MAP ≤ 70 mmHg), a normal MAP group (70 mmHg < MAP ≤ 90 mmHg), and a high MAP group (MAP > 90 mmHg). The Cox proportional hazards model and restricted cubic splines were used to assess the association between MAP and mortality. Sensitivity analyses were conducted to investigate whether MAP had different effects on mortality in different subpopulations. A total of 2885 stroke patients were included in this study. The crude 7-day and 28-day mortality was significantly higher in the low MAP group than that in the normal MAP group. By contrast, patients in the high MAP group did not have higher crude 7-day and 28-day mortality than those in the normal MAP group. After multiple adjustments using the Cox regression model, patients with low MAP were consistently associated with higher 7-day and 28-day mortality than those with normal MAP in the following subgroups: age > 60 years, male, those with or without hypertension, those without diabetes, and those without CHD (p < 0.05), but patients with high MAP were not necessarily associated with higher 7-day and 28-day mortality after adjustments (most p > 0.05). Using the restricted cubic splines, an approximately L-shaped relationship was established between MAP and the 7-day and 28-day mortality in acute stroke patients. The findings were robust to multiple sensitivity analyses in stroke patients. In critically ill stroke patients, a low MAP significantly increased the 7-day and 28-day mortality, while a high MAP did not, suggesting that a low MAP is more harmful than a high MAP in critically ill stroke patients.
RESUMO
Active metal ions often show a strong cutting effect on the chemical bonds during high-temperature thermal processes. Herein, a one-pot metal ion cutting-assisted method was adopted to design defect-rich MoS2-x nanosheet (NS)/ZnS nanoparticle (NP) heterojunction composites on carbon nanofiber skeletons (CNF@MoS2-x/ZnS) via a simple Ar-ambience annealing. Results show that Zn2+ ions capture S2- ions from MoS2 and form into ZnS NPs, and the MoS2 NSs lose S2- ions and become MoS2-x ones. As sulfur hosts for lithium-sulfur batteries (LSBs), the CNF@MoS2-x/ZnS-S cathodes deliver a high reversible capacity of 1233 mA h g-1 at 0.1 C and keep 944 mA h g-1 at 3 C. Moreover, the cathodes also show an extremely low decay rate of 0.012% for 900 cycles at 2 C. Series of analysis indicate that the MoS2-x NSs significantly improve the chemisorption and catalyze the kinetic process of redox reactions of lithium polysulfides, and the heterojunctions between MoS2-x NSs and ZnS NPs further accelerate the transport of electrons and the diffusion of Li+ ions. Besides, the CNF@MoS2-x/ZnS-S LSBs also show an ultralow self-discharge rate of 1.1% in voltage. This research would give some new insights for the design of defect-rich electrode materials for high-performance energy storage devices.
RESUMO
Carbon nanotubes (CNTs) are often used to settle down the sluggish reaction kinetics in lithium-sulfur batteries (LSBs). However, the self-aggregation of CNTs often makes them fail to effectively inhibit the shuttling effect of soluble lithium polysulfide (LiPS) intermediates. Herein, a type of ultra-stable carbon micro/nano-scale interconnected "carbon cages" has been designed by incorporating polar acid-treated carbon fibers (ACF) into three-dimensional (3D) CNT frameworks during vacuum filtration processes. Results show that the ACF-CNT composite frameworks possess a reinforced-concrete-like structure, in which the ACFs can well work as the main mechanical supporting frames for the composite electrodes, and the oxygen-containing functional groups (OFGs) formed on them as cross linker between ACFs and CNTs. Benefitted from this design, the ACF-CNT/S cathodes deliver an excellent rate capability (retain 72.6% at 4C). More impressively, the ACF-CNT/S cathodes also show an ultrahigh cycling stability (capacity decay rate of 0.001% per cycle over 350 cycles at 2C). And further optimization suggests that the suitable treatment on CFs could balance the chemical adsorption (OFGs) and physical confinement (carbon cages), leading to fast and durable electrochemical reaction dynamics. In addition, the assembled soft-pack LSBs further show a high dynamic bending stability.
RESUMO
Nanowire solar cells: Pt nanoparticle (PtNP) decorated C/Si core/shell nanowire photoelectrochemical solar cells show high conversion efficiency of 10.86 % and excellent stability in aggressive electrolytes under 1-sun AM 1.5 G illumination. Superior device performance is achieved by improved surface passivation of the nanowires by carbon coating and enhanced interfacial charge transfer by PtNPs.
Assuntos
Fontes de Energia Elétrica , Nanofios/química , Silício/química , Energia Solar , Carbono/química , Nanopartículas Metálicas/química , Tamanho da Partícula , Processos Fotoquímicos , Platina/química , Propriedades de SuperfícieRESUMO
SnO2/TiO2 type II heterojunctions are often introduced to enhance the separation efficiency of photogenerated carriers in photoelectrochemical electrodes, while most of these heterojunctions are of core-shell structure, which often limits the synergistic effect from the two components. In this work, dissymmetric SnO2/TiO2 side-by-side bi-component nanofibers (SBNFs) with tunable composition ratios have been prepared by a novel needleless electrospinning technique with two V-shape connected conductive channels (V-channel electrospinning). Results show that this V-channel electrospinning technique is more stable, controllable and tunable for the large-scale preparation of SBNF materials compared to the traditional electrospinning using two side-by-side metal needles. And these SnO2/TiO2 SBNFs are dissymmetric and comprised of a tiny SnO2 NF (tunable diameter within 20-80 nm) and a Sn-doped TiO2 NF (diameter of ~ 250 nm) with a side-by-side structure. Moreover, the dye-sensitized solar cells (DSSCs) based these dissymmetric SnO2/TiO2 SBNFs show the maximum power conversion efficiency (PCE) of 8.3%, which is 2.59 times that of the ones based on the TiO2 NFs. Series of analyses indicate that the enhancements in PCE could mainly be due to the improved electron transport via SnO2 NFs and the enhanced carrier separation via dissymmetric SnO2/TiO2 heterojunction interface. This research will give some new insight in the preparation of SBNFs for high-performance photoelectrochemical devices.
RESUMO
OBJECTIVE: To develop a method for determination of clozapine, olanzapine and mirtazapine in human plasma by liquid chromatography-tandem mass spectrometry(LC-MS/MS). METHODS: Clozapine, olanzapine and mirtazapine were extracted from plasma samples by using diethyl ether and separated by Agilent Zorbax SB-C18 column(2.1 mm x 150 mm, 5 microm). Electrospray ionization source was applied, positive ion mode was used to detect and multiple reaction monitoring mode was used to quantify clozapine, olanzapine and mirtazapine. Carbamazepine was the internal standard. RESULTS: The detection limits of clozapine, olanzapine and mirtazapine were within 0.41-0.92 ng/mL. The calibration curve in the concentration range of 10.0-2000.0 ng/mL showed a good linear distribution (r > or = 0.992 4). The average extraction recoveries were within 65.7%-94.2%. Intra-day RSD and inter-day RSD were less than 6% (n = 5). CONCLUSION: This method seems to be quite specific, sensitive and accurate, and can be used to detect clozapine, olanzapine and mirtazapine in forensic and clinical analytic toxicology.
Assuntos
Benzodiazepinas/sangue , Cromatografia Líquida , Clozapina/sangue , Mianserina/análogos & derivados , Espectrometria de Massas em Tandem , Cromatografia Líquida/métodos , Toxicologia Forense , Humanos , Mianserina/sangue , Mirtazapina , Olanzapina , Espectrometria de Massas em Tandem/métodosRESUMO
Laboratory animals and animal experiments are foundations and important support conditions for life sciences, especially for medical research. The animal experiments have drawn extensive attention from the society because of the ethical issue. This paper takes Wenzhou Medical University as an example to give a brief introduction to the ethical review about laboratory animals in the university so as to further draw attention and concerns from the public about the ethical issue of laboratory animals. We successively introduce its scientific projects, nurturing environment and ethical review of laboratory animals.