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BACKGROUND AIMS: As a global health threat, NASH has been confirmed to be a chronic progressive liver disease that is strongly associated with obesity. However, no approved drugs or efficient therapeutic strategies are valid, mainly because its complicated pathological processes is underestimated. APPROACH RESULTS: We identified the RING-type E3 ubiquitin transferase-tripartite motif-containing protein 31 (TRIM31), a member of the E3 ubiquitin ligases family, as an efficient endogenous inhibitor of transforming growth factor-beta-activated kinase 1 (mitogen-activated protein kinase kinase kinase 7; MAP3K7), and we further confirmed that TRIM31 is an MAP3K7-interacting protein and promotes MAP3K7 degradation by enhancing ubiquitination of K48 linkage in hepatocytes. Hepatocyte-specific Trim31 deletion blocks hepatic metabolism homeostasis, concomitant with glucose metabolic syndrome, lipid accumulation, up-regulated inflammation, and dramatically facilitates NASH progression. Inversely, transgenic overexpression, lentivirus, or adeno-associated virus-mediated Trim31 gene therapy restrain NASH in three dietary mice models. Mechanistically, in response to metabolic insults, TRIM31 interacts with MAP3K7 and conjugates K48-linked ubiquitination chains to promote MAP3K7 degradation, thus blocking MAP3K7 abundance and its downstream signaling cascade activation in hepatocytes. CONCLUSIONS: TRIM31 may serve as a promising therapeutic target for NASH treatment and associated metabolic disorders.
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Hepatopatia Gordurosa não Alcoólica , Proteínas com Motivo Tripartido , Ubiquitina-Proteína Ligases , Animais , Camundongos , MAP Quinase Quinase Quinases/metabolismo , Hepatopatia Gordurosa não Alcoólica/metabolismo , Hepatopatia Gordurosa não Alcoólica/prevenção & controle , Ubiquitina-Proteína Ligases/metabolismo , Ubiquitinação , Humanos , Proteínas com Motivo Tripartido/metabolismoRESUMO
Macrophorins H (4) and L (5), two rare HMG-conjugate macrophorins along with three known macrophorins (1-3), three DMOA-derived meroterpenoids (6-8) and two ergosterol derivates (9-10) were isolated from sterilized rice medium cultured Penicillium sp. NX-05-G-3. Their structures were elucidated by 1D and 2D NMR. The cytotoxicities of all compounds were evaluated, and compounds 1 and 2 showed extensive cytotoxicity against human cancer cell lines Hela, SCC15, MDA-MB-453 and A549, with IC50 values ranging from 17.6 to 32.8 µM.
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Ensaios de Seleção de Medicamentos Antitumorais , Penicillium , Penicillium/química , Humanos , Estrutura Molecular , Células HeLa , Antineoplásicos/farmacologia , Antineoplásicos/química , Linhagem Celular Tumoral , Terpenos/farmacologia , Terpenos/químicaRESUMO
A facile and efficient visible-light-mediated method for directly converting 1,4-naphthoquinones into dihydrocyclo-buta[b]naphthalene-3,8-diones (DHCBNDOs) under mild and clean conditions without using any photocatalysts is reported. This approach exhibited favorable compatibility with functional groups and afforded a series of DHCBNDOs with excellent regioselectivity and high yields. Moreover, detailed mechanism studies were carried out both experimentally and theoretically. The readily accessible, low-cost and ecofriendly nature of the developed strategy will endow it with attractive applications in organic and medicinal chemistry.
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Sesquiterpenes are one of the most diverse groups of secondary metabolites that have mainly been observed in terpenoids. It is a natural terpene containing 15 carbon atoms in the molecule and three isoprene units with chain, ring, and other skeleton structures. Sesquiterpenes have been shown to display multiple biological activities such as anti-inflammatory, anti-feedant, anti-microbial, anti-tumor, anti-malarial, and immunomodulatory properties; therefore, their therapeutic effects are essential. In order to overcome the problem of low-yielding sesquiterpene content in natural plants, regulating their biosynthetic pathways has become the focus of many researchers. In plant and microbial systems, many genetic engineering strategies have been used to elucidate biosynthetic pathways and high-level production of sesquiterpenes. Here, we will introduce the research progress and prospects of the biosynthesis of artemisinin, costunolide, parthenolide, and dendrobine. Furthermore, we explore the biosynthesis of dendrobine by evaluating whether the biosynthetic strategies of these sesquiterpene compounds can be applied to the formation of dendrobine and its intermediate compounds. KEY POINTS: ⢠The development of synthetic biology has promoted the study of terpenoid metabolism and provided an engineering platform for the production of high-value terpenoid products. ⢠Some possible intermediate compounds of dendrobine were screened out and the possible pathway of dendrobine biosynthesis was speculated. ⢠The possible methods of dendrobine biosynthesis were explored and speculated.
Assuntos
Alcaloides , Sesquiterpenos , Vias Biossintéticas , TerpenosRESUMO
Red deer (Cervus elaphus) blood is widely used as a health product. Mixed culture fermentation improves the flavor and bioavailability of deer blood (DB), and both DB and its enzymatic hydrolysates exhibit anti-fatigue activities in vivo. To elucidate the bioactive ingredients, enzymatic hydrolysates were fractioned into different peptide groups using reversed phase resin chromatography, and then evaluated using an exhaustive swimming mice model to assess swimming time and biochemical parameters. The structures of the bioactive peptides were elucidated by high performance liquid chromatography with tandem mass detection. Thirty-one compounds were identified as glutamine or branched-chain amino acids containing short peptides, of which Val-Ala-Asn, Val-Val-Ser-Ala, Leu(Ile)-Leu(Ile)-Val-Thr, Pro-His-Pro-Thr-Thr, Glu-Val-Ala-Phe and Val-Leu(Ile)-Asp-Ala-Phe are new peptides. The fractions containing glutamine or valine short peptides, Ala-Gln, Val-Gln, Val-Val-Ser-Ala, Val-Leu(Ile)-Ser improved exercise endurance by increasing hepatic glycogen (HG) storage. The peptides group containing Leu(Ile)-Leu(Ile), Asp-Gln, Phe- Leu(Ile), Val-Val-Tyr-Pro contributed to decreased muscle lactic acid (MLA)accumulation and to an increase in HG. The anti-fatigue activities of DB hydrolysates were attributed to the synergistic effects of different types of peptides.
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Proteínas Sanguíneas/química , Sangue , Cervos/sangue , Fadiga/metabolismo , Oligopeptídeos , Hidrolisados de Proteína/química , Animais , Camundongos , Oligopeptídeos/química , Oligopeptídeos/farmacologiaRESUMO
Nonalcoholic fatty liver disease (NAFLD) is featured by hepatic steatosis, insulin resistance, lipid deposition and inflammation. However, the pathogenic mechanism of NAFLD is still poorly understood. Dual-specificity phosphatase 16 (DUSP16), a c-Jun N-terminal kinase-specific phosphatase, has been reported to negatively modulate the mitogen-activated protein kinases (MAPKs) signaling, and it has never been investigated in NAFLD progression. In the study, we identified that DUSP16 could directly interact with TAK1 in human hepatocytes. DUSP16 knockdown in the isolated primary hepatocytes stimulated by palmitate (PA) showed accelerated lipid deposition and inflammatory response, along with the exacerbated activation of c-Jun NH2-terminal kinase (JNK), Transforming growth factor ß (TGF-ß)-activated kinase (TAK1) and nuclear factor-κB (NF-κB) signaling pathways; however, the opposite results were detected in PA-treated hepatocytes with DUSP16 over-expression. The in vivo experiments confirmed that DUSP16 knockout significantly aggravated the metabolic disorder and insulin resistance in high fat diet (HFD)-challenged mice. In addition, HFD-provoked hepatic lipid accumulation and inflammation were further promoted in mice with DUSP16 knockout through the same molecular mechanism as detected in vitro. Herein, these findings demonstrated that DUSP16 could directly interact with TAK1 and negatively regulate JNK signaling to alleviate metabolic stress-induced hepatic steatosis, and thus could be considered as a promising new molecular target for NAFLD treatment.
Assuntos
Dieta Hiperlipídica , Fosfatases de Especificidade Dupla/metabolismo , Dislipidemias/complicações , Inflamação/complicações , Proteínas Quinases JNK Ativadas por Mitógeno/metabolismo , Fígado/enzimologia , Fígado/patologia , MAP Quinase Quinase Quinases/metabolismo , Fosfatases da Proteína Quinase Ativada por Mitógeno/metabolismo , Transdução de Sinais , Animais , Linhagem Celular , Comportamento Alimentar , Hepatócitos/enzimologia , Hepatócitos/patologia , Humanos , Masculino , Camundongos Endogâmicos C57BL , Camundongos Knockout , Ácido Palmítico , Ligação ProteicaRESUMO
Intracerebral hemorrhage (ICH) is one of the leading causes of death and long-term disability worldwide. Mesenchymal stem cell (MSC) therapies have demonstrated improved outcomes for treating ICH-induced neuronal defects, and the neural network reconstruction and neurological function recovery were enhanced in rodent ICH models through the mechanisms of neurogenesis, angiogenesis, anti-inflammation, and anti-apoptosis. However, many key issues associated with the survival, differentiation, and safety of grafted MSCs after ICH remain to be resolved, which hinder the clinical translation of MSC therapy. Herein, we reviewed an overview of the research status of MSC transplantation after ICH in different species including rodents, swine, monkey, and human, and the challenges for MSC-mediated ICH recovery from pathological microenvironment have been summarized. Furthermore, some efficient strategies for the outcome improvement of MSC transplantation were proposed.
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Mitochondria, as the powerhouse of most cells, are not only responsible for the generation of adenosine triphosphate (ATP) but also play a decisive role in the regulation of apoptotic cell death, especially of cancer cells. Safe potential delivery systems which can achieve organelle-targeted therapy are urgently required. In this study, for effective pancreatic cancer therapy, a novel mitochondria-targeted and ROS-triggered drug delivery nanoplatform was developed from the TPP-TK-CPI-613 (TTCI) prodrug, in which the ROS-cleave thioketal functions as a linker connecting mitochondrial targeting ligand TPP and anti-mitochondrial metabolism agent CPI-613. DSPE-PEG2000 was added as an assistant component to increase accumulation in the tumor via the EPR effect. This new nanoplatform showed effective mitochondrial targeting, ROS-cleaving capability, and robust therapeutic performances. With active mitochondrial targeting, the formulated nanoparticles (TTCI NPs) demonstrate much higher accumulation in mitochondria, facilitating the targeted delivery of CPI-613 to its acting site. The results of in vitro antitumor activity and cell apoptosis revealed that the IC50 values of TTCI NPs in three types of pancreatic cancer cells were around 20~30 µM, which was far lower than those of CPI-613 (200 µM); 50 µM TTCI NPs showed an increase in apoptosis of up to 97.3% in BxPC3 cells. Therefore, this mitochondria-targeted prodrug nanoparticle platform provides a potential strategy for developing safe, targeting and efficient drug delivery systems for pancreatic cancer therapy.
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Ambient particulate matter (PM2.5)-induced metabolic syndromes is a critical contributor to the pathological processes of neurological diseases, but the underlying molecular mechanisms remain poorly understood. The rhomboid 5 homolog 2 (Rhbdf2), an essential regulator in the production of TNF-α, has recently been confirmed to exhibit a key role in regulating inï¬ammation-associated diseases. Thus, we examined whether Rhbdf2 contributes to hypothalamic inflammation via NF-κB associated inflammation activation in long-term PM2.5-exposed mice. Specifically, proopiomelanocortin-specific Rhbdf2 deficiency (Rhbdf2Pomc) and corresponding littermates control mice were used for the current study. After 24 weeks of PM2.5 inhalation, systemic-metabolism disorder was confirmed in WT mice in terms of impaired glucose tolerance, increased insulin resistance, and high blood pressure. Markedly, PM2.5-treated Rhbdf2Pomc mice displayed a significantly opposite trend in these parameters compared with those of the controls group. We next confirmed hypothalamic injury accompanied by abnormal POMC neurons loss, as indicated by increased inflammatory cytokines, chemokines, and oxidative-stress levels and decreased antioxidant activity. These results were further supported by blood routine examination. In summary, our findings suggest that Rhbdf2 plays an important role in exacerbating PM2.5-stimulated POMC neurons loss associated hypothalamic injury, thus providing a possible target for blocking pathological development of air pollution-associated diseases.
Assuntos
Poluentes Atmosféricos , Material Particulado , Poluentes Atmosféricos/toxicidade , Animais , Inflamação/induzido quimicamente , Inflamação/genética , Camundongos , Neurônios , Estresse Oxidativo , Material Particulado/toxicidade , Pró-OpiomelanocortinaRESUMO
Biomechanical methods may provide a novel way to understand blood accumulation in intracerebral hemorrhage (ICH). The current study presents the results of a biomechanical analysis of blood accumulation in ICH using a finite element analysis, with an emphasis on the pressure exerted by the mass effect of blood in early ICH. A two-dimensional finite model of the human brain parenchyma and the human ventricular system was developed and analyzed under two preloading conditions. The material properties of the human parenchyma were derived from previous reports. Ogden's theory was applied to describe the stress-strain association in soft tissue. The results of the present study indicated that maximal stress was located at the two ends of the hemorrhage cavity, with the majority of stresses distributed on the zone surrounding the bleed. The two load environments demonstrated similar stress distributions. The loads put on the detached edges were not less than the intracranial pressure (ICP) when the stress threshold was reached. The results of the present study suggest that the direction of blood accumulation can be determined by the shape of the initial blood mass. Mechanical factors (blood pressure and ICP) did not serve a definitive role in preventing blood from accumulating in the early stages of ICH. The present study may aid in understanding the effects of mechanical factors in blood accumulation and hemostasis in patients with early ICH.
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Endoplasmic reticulum stress (ERS) has been implicated in obesity-associated cardiac remodeling and dysfunction. Inactive rhomboid protein 2 (iRhom2), also known as Rhbdf2, is an inactive member of the rhomboid intramembrane proteinase family, playing an essential role in regulating inflammation. Nevertheless, the role of ERS-meditated iRhom2 pathway in metabolic stress-induced cardiomyopathy remains unknown. In the study, we showed that 4-PBA, as an essential ERS inhibitor, significantly alleviated high fat diet (HFD)-induced metabolic disorder and cardiac dysfunction in mice. Additionally, lipid deposition in heart tissues was prevented by 4-PBA in HFD-challenged mice. Moreover, 4-PBA blunted the expression of iRhom2, TACE, TNFR2 and phosphorylated NF-κB to prevent HFD-induced expression of inflammatory factors. Further, 4-PBA restrained HFD-triggered oxidative stress by promoting Nrf-2 signaling. Importantly, 4-PBA markedly suppressed cardiac ERS in HFD mice. The anti-inflammation, anti-ERS and anti-oxidant effects of 4-PBA were verified in palmitate (PAL)-incubated macrophages and cardiomyocytes. In addition, promoting ERS could obviously enhance iRhom2 signaling in vitro. Intriguingly, our data demonstrated that PAL-induced iRhom2 up-regulation apparently promoted macrophage to generate inflammatory factors that could promote cardiomyocyte inflammation and lipid accumulation. Finally, interventions by adding fisetin or metformin significantly abrogated metabolic stress-induced cardiomyopathy through the mechanisms mentioned above. In conclusion, this study provided a novel mechanism for metabolic stress-induced cardiomyopathy pathogenesis. Therapeutic strategy to restrain ROS/ERS/iRhom2 signaling pathway could be developed to prevent myocardial inflammation and lipid deposition, consequently alleviating obesity-induced cardiomyopathy.
Assuntos
Proteínas de Transporte/metabolismo , Estresse do Retículo Endoplasmático , Flavonoides/farmacologia , Coração/fisiopatologia , Metabolismo dos Lipídeos , Metformina/farmacologia , Animais , Peso Corporal , Dieta Hiperlipídica , Ecocardiografia , Flavonóis , Regulação da Expressão Gênica , Coração/efeitos dos fármacos , Inflamação , Macrófagos/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Miocárdio/patologia , Estresse Oxidativo , Palmitatos/metabolismo , Transdução de Sinais , Regulação para CimaRESUMO
Intracerebral hemorrhage (ICH) may lead to physical and pathological damage and has been a focus of research for decades. Evaluating tensile damage caused by deformation in ICH is an important component of damage assessment for correct diagnosis and treatment. Traditional research on ICH paid little attention to quantified brain tissue damage resulting from mechanical factors, and only a few reported the mechanical properties of damaged brain tissue. The aim of the present study was to present an effective method that is able to evaluate the tissue damage degree in ICH, based on strain energy function. Two finite element analysis (FEA) models were analyzed: A three-dimensional (3D) model for tissue's tension experiment and a two-dimensional (2D) model for brain tissue's deformation in ICH. The polynomial fitting function of stress vs. stretch curve, which was derived from previous reports, was used in the FEA as the constitutive function of brain tissue. The present study demonstrated that white matter could be regarded as hyperelastic material when stretch was <1.343, and with stretch increasing, tissue injury exacerbated when stretch was >1.343. The strain energy loss was not linear in this process, and Neo-Hookean and Ogden model's results demonstrated a similar change in trend, but a difference in quantity. The results from 2D and 3D simulation, respectively, demonstrated the degree of damage according to the above dividing criteria and the possible distribution of tissue damage after ICH ictus. An analytical model from a biomechanical perspective for white matter injury in ICH may facilitate to improve clinical diagnosis and treatment.
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Gossypol, a secondary metabolite stored in the glands of cotton, protecting cottonseed from consumption of human and monogastric animal. This ability is unique to the tribe Gossypieae. Although the relationship between gossypol and pigment gland has been studied for a long time, the development mechanism of pigment gland has not been investigated at molecular level. Here we described a simple and efficient method for constructing a normalized cDNA library from a cotton mutant, Xiangmian-18, during its pigments gland forming stage. It combined switching mechanism at 5'-end of RNA transcript (SMART) technique and duplex-specific nuclease (DSN) normalization methods. In a model experiment, double-stranded cDNAs were synthesized from mRNAs, processed by normalization and Sfi I restriction endonuclease, and finally the cDNAs were ligated to pDNR-LIB vector. The ligation mixture was transformed into E. coli JM109 by electroporation. Counting the number of colonies, the titer of the original library was 5.86x10(5)cfu/ml in this library. Electrophoresis gel results indicated the fragments ranged from 800bp to 2kb, with the average size of 1400bp. Random picking clones showed that the recombination rate was 94%. The results showed that the cDNA library constructed successfully was a full-length library with high quality, and could be used to screen the genes related to development of pigments gland cottons.
Assuntos
DNA Complementar/genética , Biblioteca Gênica , Gossypium/genética , Sementes/genética , DNA Complementar/biossíntese , Regulação da Expressão Gênica no Desenvolvimento/genética , Gossypium/química , Mutação , Reação em Cadeia da Polimerase , RNA Mensageiro/genéticaRESUMO
AIM: Nineteen compounds related to salicylic acid were evaluated for their in vitro activity of inhibiting beta-lactamase isolated from a resistant strain of Pseudomonas aeruginosa, and their structure-activity relationships were examined. METHODS: Nitrocefin method was used. RESULTS: The 50% inhibitory concentration (IC50) of salicylic acid inhibiting beta-lactamase was 22 mmol x L(-1); four analogs had IC50 lower than that of salicylic acid; fifteen analogs had IC50 higher than that of salicylic acid. CONCLUSION: Examination of the structure-activity relationships of the compounds revealed that carboxyl group and adjoining hydroxyl group were active group, and replacement of adjoining hydroxyl by carboxyl increased activity nearly 4-fold. Moreover, addition of a sulfonic group at C-5 and nitro group at C-3, 5 of benzenoic ring of salicylic acid resulted in a 2-fold to 3-fold increase in activity, addition of a amino group at C-5 of benzenoic ring of salicylic acid decreased activity, add addition of -Cl or -F at C-2,4 position of benzenoic ring of benzoic acid did not show activity.
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Antibacterianos/síntese química , Salicilatos/síntese química , beta-Lactamases/metabolismo , Antibacterianos/química , Antibacterianos/farmacologia , Cefalosporinas/metabolismo , Concentração Inibidora 50 , Pseudomonas aeruginosa/enzimologia , Salicilatos/química , Salicilatos/farmacologia , Relação Estrutura-Atividade , beta-Lactamases/isolamento & purificaçãoRESUMO
Expression difference of heterologous recombinant protein in Pichia pastoris with different specific growth rate (mu) was observed. The expression conditions of recombinant human interferon omega (rhIFN(omega)) in logarithm phrase Pichia pastoris with higher mu were optimized by shake flask tests under various initial pH, methanol concentration, duration of the induction, cell density, and medium volume. The results showed that there were prominent influences of mu on expression of rhlFN(omega). The maximum yield of rhIFN(omega) in the Pichia pastoris with mu of 0.1612 h(-1) was 558 mg/L. However, these in the Pichia pastoris with mu of 0.1321, 0.0505 and 0.0052 h(-1) were reduced by 50%, 68% and 99%, respectively. In 250 mL shake flask, the optimal medium volume, cell density, initial pH, methanol concentration, frequency and duration of methanol induction were 30 mL, 200 - 300 g/L (WCW), natural, 15 g/L, 1 time in every 24h and 4d, respectively. Under the optimal expression condition, the maximum yield of rhIFN(omega) in logarithm phrase Pichia pastoris was 1070 mg/L which was increased by 149% more than that under the initial condition.
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Interferon Tipo I/genética , Pichia/crescimento & desenvolvimento , Pichia/genética , Proteínas Recombinantes/genética , Contagem de Células , Meios de Cultura/farmacologia , Relação Dose-Resposta a Droga , Expressão Gênica/efeitos dos fármacos , Humanos , Concentração de Íons de Hidrogênio , Interferon Tipo I/biossíntese , Metanol/farmacologia , Pichia/citologia , Proteínas Recombinantes/biossínteseRESUMO
OBJECTIVE: To detect the polysaccharides content of tissue culturing seedlings on Dendrobium candidium under special sound wave stimulation. METHODS: The content of polysaccharides was detected by phenol-vitriol colorimetry method. RESULTS: The polysaccharides content of the groups stimulated continuously for 24d was higher obviously than the content of the control groups. CONCLUSION: The stimulation of the special sound wave promoted markedly the synthesis of polysaccharides in D. candidium. It may affect obviously the metabolic pathway of polysaccharides in D. candidium.
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Dendrobium/crescimento & desenvolvimento , Plantas Medicinais/crescimento & desenvolvimento , Polissacarídeos/metabolismo , Colorimetria/métodos , Técnicas de Cultura/métodos , Dendrobium/química , Fotossíntese , Plantas Medicinais/química , Polissacarídeos/isolamento & purificação , Plântula/química , Plântula/crescimento & desenvolvimento , Som , Fatores de TempoRESUMO
In the current study, we found that the stress stimulus can act as a kind of elicitor, which can efficiently induce the resistance of cucumber against fungal pathogen. After the treatment of the stress stimulus on leaves, the activities of resistance-related enzymes were increased significantly. Such as phenylamine ammonia lyase (PAL), peroxidase (POD) and polyphenoloxidase (PPO), which are strongly associated with the plant disease resistance. Also the expression of pathogenesis-related protein (PR protein) were activated by stress stimulus, with the results that the activities of chitinase and beta-l,3-glucanase were increased obviously. The data showed that one of the mechanism of stress stimulus induction plant resistance may act via eliciting the metabolism related disease resistance within plant, which can produce many suppressing and antimicrobial compounds to against pathogens infection efficiently.
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Cladosporium/patogenicidade , Cucumis sativus/enzimologia , Doenças das Plantas/microbiologia , Catecol Oxidase/metabolismo , Quitinases/metabolismo , Glucana 1,3-beta-Glucosidase/metabolismo , Peroxidase/metabolismo , Fenilalanina Amônia-Liase/metabolismo , Folhas de Planta/enzimologia , Pressão/efeitos adversos , Plântula/enzimologia , Transdução de SinaisRESUMO
Up to date, the studies of plant induced resistance have become the focus in plant pathology and physiology. During the course of pathogens penetrating the plant cell, besides of chemical secretion, the pathogens may generate mechanical signal caused by the physical pressure on the plant cell. In the non-host resistance, both the chemical signal and the mechanical stress signal are considered to have contribution to the entire defense reaction acted by the plant. The penetration of pathogen Cladosporium cucumerinum to cucumber is thought to be one of the model in research of plant induced resistance. In the current study, as a mechanical signal elicitor, the appropriate stress stimulus was proved to effectually induce the resistance of cucumber seedling to C. cucumerinum. After the treatment of the stress stimulus on leaves, the activities of resistance-related enzymes were significantly increased, such as phenylanine ammonia lyase (PAL), peroxidase (POD). Also, we found that stress stimulation may cause synthesis of lignin, which acts as the physical barrier to defense the pathogens. The results suggest that stress stimulation may not only enhance ability of the plant cell resistance to pathogen penetration but also elicit the accumulation of pathogens suppression or antimicrobial chemical substance in the plant cell.
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Cladosporium , Cucumis sativus/microbiologia , Peroxidases/metabolismo , Fenilalanina Amônia-Liase/metabolismo , Plântula/enzimologia , Plântula/microbiologia , Cucumis sativus/enzimologia , Lignina/biossíntese , Modelos Biológicos , Doenças das Plantas/microbiologia , Folhas de Planta/enzimologia , Folhas de Planta/microbiologia , Estresse MecânicoRESUMO
Drought is one of the major factors limiting crop production globally, with increasing global climate change making the situation more serious. Wheat is the staple food for more than 35% of world population, so wheat anti-drought physiology study is of importance to wheat production and biological breeding for the sake of coping with abiotic and biotic conditions. Much research is involved in this hot topic, but the pace of progress is not so large because of drought resistance being a multiple-gene-control quantitative character and wheat genome being larger (16,000 Mb). On the other hand, stress adaptive mechanisms are quite different, with stress degree, time course, materials, and experimental plots, thus increasing the complexity of the issue in question. Additionally, a little study is related to the whole life circle of wheat, which cannot provide a comprehensive understanding of its anti-drought machinery. We selected 10 kinds of wheat genotypes as materials, which have potential to be applied in practice, and measured relative change of anti-oxidative enzymes and membrane peroxidation through wheat whole growth-developmental circle (i.e. seedling, tillering and maturing). Here, we firstly reported the results of seedling stage as follows: (1) 10 wheat genotypes can be grouped into three kinds (A-C, respectively) according to their changing trend of the measured indices; (2) A performed better resistance drought under the condition of treatment level 1 (appropriate level), whose activities of anti-oxidative enzymes (POD, SOD, CAT) were higher and MDA lower and chlorophyll a+b higher; (3) B exhibited stronger anti-drought under treatment level 2 (light stress level), whose activities of anti-oxidative enzymes were higher, MDA lower and chlorophyll higher; (4) C expressed anti-drought to some extent under treatment level 3 (serious stress), whose activities of anti-oxidative enzymes were stronger, MDA lower and chlorophyll higher; (5) these results demonstrated that different wheat genotypes have different physiological mechanisms to adapt themselves to changing drought stress, whose molecular basis is discrete gene expression profiling (transcriptom); (6) our results also showed that the concept accepted by most researchers, 70-75% QF is a proper supply for plants, was doubted, because this level could not reflect the true suitable level of wheat. The study in this respect is the key to wheat anti-drought and biological saving-water; (7) our research can provide insights into physiological mechanisms of crop anti-drought and direct practical materials for wheat anti-drought breeding.
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Antioxidantes/farmacologia , Catalase/biossíntese , Membrana Celular/metabolismo , Genótipo , Peroxidase/biossíntese , Superóxido Dismutase/biossíntese , Triticum/genética , Triticum/metabolismo , Catalase/genética , Clorofila/metabolismo , Desastres , Genes de Plantas , Genoma de Planta , Peroxidase/genética , Plântula/metabolismo , Solo , Superóxido Dismutase/genética , ÁguaRESUMO
The ethanolic extracts of eight traditional Chinese medicines and four antibiotics were investigated for their combined effects on the resistance of Staphylococcus aureus (S. aureus) in vitro. Methicillin resistant S. aureus, which was isolated from patient and a standard strain, were used. Our results showed that there are differences in the effects of many combinations used on the standard strain and resistant strain of S. aureus. The ethanolic extracts of Isatis tinctoria, Scutellaria baicalensis and Rheum palmatum can improve the antimicrobial activity of four antibiotics we used.