RESUMEN
Arabidopsis MORE AXILLARY GROWTH2 (MAX2) is a key component in the strigolactone (SL) and karrikin (KAR) signaling pathways and regulates the degradation of SUPPRESSOR OF MAX2 1/SMAX1-like (SMAX1/SMXL) proteins, which are transcriptional co-repressors that regulate plant architecture, as well as abiotic and biotic stress responses. The max2 mutation reduces resistance against Pseudomonas syringae pv. tomato (Pst). To uncover the mechanism of MAX2-mediated resistance, we evaluated the resistance of various SL and KAR signaling pathway mutants. The resistance of SL-deficient mutants and of dwarf 14 (d14) was similar to that of the wild-type, whereas the resistance of the karrikin insensitive 2 (kai2) mutant was compromised, demonstrating that the KAR signaling pathway, not the SL signaling pathway, positively regulates the immune response. We measured the resistance of smax1 and smxl mutants, as well as the double, triple, and quadruple mutants with max2, which revealed that both the smax1 mutant and smxl6/7/8 triple mutant rescue the low resistance phenotype of max2 and that SMAX1 accumulation diminishes resistance. The susceptibility of smax1D, containing a degradation-insensitive form of SMAX1, further confirmed the SMAX1 function in the resistance. The relationship between the accumulation of SMAX1/SMXLs and disease resistance suggested that the inhibitory activity of SMAX1 to resistance requires SMXL6/7/8. Moreover, the exogenous application of KAR2 enhanced resistance against Pst, but KAR-induced resistance depended on salicylic acid (SA) signaling. Inhibition of karrikin signaling delayed SA-mediated defense responses and inhibited pathogen-induced protein biosynthesis. Together, we propose that the MAX2-KAI2-SMAX1 complex regulates resistance with the assistance of SMXL6/7/8 and SA signaling and that SMAX1/SMXLs possibly form a multimeric complex with their target transcription factors to fine tune immune responses.
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Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/genética , Arabidopsis/metabolismo , Proteínas de Arabidopsis/metabolismo , Lactonas/metabolismo , Lactonas/farmacología , Transducción de Señal , Regulación de la Expresión Génica de las Plantas , Péptidos y Proteínas de Señalización Intracelular/genética , Péptidos y Proteínas de Señalización Intracelular/metabolismoRESUMEN
WRKY transcription factors (TFs) play crucial roles in biotic and abiotic stress responses. However, their roles in thermal response are still largely elusive, especially in rice. In this study, we revealed the functions of WRKY10 TF and VQ8 protein containing VQ motif in rice thermotolerance. Overexpression of WRKY10 or loss of VQ8 function increases thermosensitivity, whereas conversely, overexpression of VQ8 or loss of WRKY10 function enhances thermotolerance. Overexpression of WRKY10 accelerates reactive oxygen species (ROS) accumulation in chloroplasts and apoplasts, and it also induces the expression of heat shock TF and protein genes. We also found that WRKY10 regulates nuclear DNA fragmentation and hypersensitive response by modulating NAC4 TF expression. The balance between destructive and protective responses in WRKY10-overexpression plant is more fragile and more easily broken by heat stress compared with wild type. In vitro and in vivo assays revealed that VQ8 interacts with WRKY10 and inhibits the transcription activity via repressing its DNA-binding activity. Our study demonstrates that WRKY10 negatively regulates thermotolerance by modulating the ROS balance and the hypersensitive response and that VQ8 functions antagonistically to positively regulate thermotolerance. The functional module of WRKY10-VQ8 provides safe and effective regulatory mechanisms in the heat stress response.
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Oryza , Termotolerancia , Regulación de la Expresión Génica de las Plantas , Respuesta al Choque Térmico/genética , Oryza/genética , Oryza/metabolismo , Proteínas de Plantas/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Termotolerancia/genéticaRESUMEN
ARABIDOPSIS: SMAX1/SMXL (SUPPRESSOR OF MAX2 1/SMAX1-LIKE) proteins function as transcriptional repressors in karrikin and strigolactone (SL) signaling pathways and regulate plant architecture. MAX2 is a common factor in the two signaling pathways and a component of the SCF complex that modulates the proteasome-mediated degradation of SMAX1/SMXLs. SMXL6, 7, and 8 proteins promote shoot branching and inhibit petiole elongation. Our study found that the accumulation of SMAX1 suppresses rosette shoot branching and increases cauline branches on the primary inflorescence stem, plant height, petiole length, and leaf length/width ratio. The SMAX1 accumulation enhances the expression of BRC1, HB53, HB40, and HB21 that modulate shoot branching. SMAX1 also regulates the expression of the genes involved in auxin transport, cytokinin signaling pathway, and SL biosynthesis. The expression analyses of these genes suggest that excessive SMAX1 should accelerate the transport of auxin and the biosynthesis of SL in plants. High SL concentration suppresses the bud development in smax1D mutant that accumulates SMAX1 protein in plant. However, the effects of cytokinin and auxin on shoot branching remain elusive in the mutant with excessive SMAX1. SMAX1 regulates leaf shape and petiole length via modulating TCP1 expression. Our findings reveal a novel function of SMAX1 and new mechanism of shoot branching.
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Proteínas de Arabidopsis/metabolismo , Arabidopsis/crecimiento & desarrollo , Arabidopsis/metabolismo , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Hojas de la Planta/anatomía & histología , Hojas de la Planta/crecimiento & desarrollo , Brotes de la Planta/anatomía & histología , Brotes de la Planta/crecimiento & desarrollo , Arabidopsis/anatomía & histología , Arabidopsis/citología , Proteínas de Arabidopsis/genética , Proteínas Portadoras/metabolismo , Núcleo Celular , Citocininas/metabolismo , Ácidos Indolacéticos/metabolismo , Péptidos y Proteínas de Señalización Intracelular/genética , Espacio Intracelular/metabolismo , Hojas de la Planta/metabolismo , Brotes de la Planta/metabolismo , Transporte de Proteínas , Transducción de Señal , Factores de Transcripción/metabolismoRESUMEN
The common pathway for pancreatitis onset is pancreatic ischemia reperfusion injury (IRI), which plays an especially significant role in the evolution process from acute edematous pancreatitis (AP) towards severe acute pancreatitis (SAP). This study explored the effect of Kallikrein (PK) on pancreatic ischemia reperfusion injury (IRI). Male Wistar rats were taken as study objects, and a SAP -IRI combined model was established through retrograde infusion of 5% sodium taurocholate in biliopancreatic duct combining 30 min splenic artery clipping; drug intervention was carried out by pumping PK into rat caudal vein. Pancreatic microcirculation blood flow, pancreatic micro vascular permeability, hemorheological change and levels of adherence factors CD18 and CD54 were determined respectively. PK can obviously improve pancreatic microcirculation blood flow volume and velocity of IRI rats and expand arteriole; expand diameter of pancreatic blood capillary so that perfusion state tends to be stable; decrease pancreatic micro vascular permeability, reduce rat whole blood viscosity, erythrocyte deformation index and rigidity index; SAP-IRI combination reduces expression levels of white cell adhesion factor CD18 and vascular endothelial cell adhesion cell CD54 in rats. In conclusion, PK is an effective method of improving SAP pancreatic IRI microcirculation.
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Calicreínas/farmacología , Microcirculación/efectos de los fármacos , Páncreas/irrigación sanguínea , Pancreatitis/tratamiento farmacológico , Daño por Reperfusión/tratamiento farmacológico , Animales , Velocidad del Flujo Sanguíneo , Viscosidad Sanguínea , Permeabilidad Capilar , Modelos Animales de Enfermedad , Deformación Eritrocítica , Ligadura , Masculino , Pancreatitis/sangre , Pancreatitis/etiología , Pancreatitis/fisiopatología , Ratas Wistar , Daño por Reperfusión/sangre , Daño por Reperfusión/etiología , Daño por Reperfusión/fisiopatología , Índice de Severidad de la Enfermedad , Arteria Esplénica/fisiopatología , Arteria Esplénica/cirugía , Ácido TaurocólicoRESUMEN
Rhizosphere colonization by plant growth-promoting rhizobacteria (PGPR) along plant roots facilitates the ability of PGPR to promote plant growth and health. Thus, an understanding of the molecular mechanisms of the root colonization process by plant-beneficial Bacillus strains is essential for the use of these strains in agriculture. Here, we observed that an sfp gene mutant of the plant growth-promoting rhizobacterium Bacillus velezensis SQR9 was unable to form normal biofilm architecture, and differential protein expression was observed by proteomic analysis. A minor wall teichoic acid (WTA) biosynthetic protein, GgaA, was decreased over 4-fold in the Δsfp mutant, and impairment of the ggaA gene postponed biofilm formation and decreased cucumber root colonization capabilities. In addition, we provide evidence that the major WTA biosynthetic enzyme GtaB is involved in both biofilm formation and root colonization. The deficiency in biofilm formation of the ΔgtaB mutant may be due to an absence of UDP-glucose, which is necessary for the synthesis of biofilm matrix exopolysaccharides (EPS). These observations provide insights into the root colonization process by a plant-beneficial Bacillus strain, which will help improve its application as a biofertilizer.IMPORTANCEBacillus velezensis is a Gram-positive plant-beneficial bacterium which is widely used in agriculture. Additionally, Bacillus spp. are some of the model organisms used in the study of biofilms, and as such, the molecular networks and regulation systems of biofilm formation are well characterized. However, the molecular processes involved in root colonization by plant-beneficial Bacillus strains remain largely unknown. Here, we showed that WTAs play important roles in the plant root colonization process. The loss of the gtaB gene affects the ability of B. velezensis SQR9 to sense plant polysaccharides, which are important environmental cues that trigger biofilm formation and colonization in the rhizosphere. This knowledge provides new insights into the Bacillus root colonization process and can help improve our understanding of plant-rhizobacterium interactions.
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Bacillus/metabolismo , Biopelículas/efectos de los fármacos , Biopelículas/crecimiento & desarrollo , Raíces de Plantas/microbiología , Ácidos Teicoicos/metabolismo , Ácidos Teicoicos/farmacología , Bacillus/genética , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Cucumis sativus/microbiología , Medios de Cultivo/química , Mutación , Polisacáridos/metabolismo , Proteómica , Rizosfera , Ácidos Teicoicos/genéticaRESUMEN
This study aims to observe the intervention effects of Chinese herbal medicine of supplementing Qi and activating blood circulation on chronic intermittent hypoxia(CIH) composite insulin resistance(IR) mediated atherosclerosis(AS) mice model,and to observe the mechanism of SREBP-1 c signaling molecule.IR Apo E-/-mice model was induced by high-fat diet combined with STZ injection.Then the mice were treated with hypoxic animal incubator for 8 h per day and 8 weeks to establish a CIH+IR-ApoE-/-mouse model.Model mice were randomly and averagely divided into normoxic control group(NC),model group(CIH) and SREBPs inhibitor group(betulin),atorvastatin group(WM),TCM low-dose group(TCM-L),TCM middle-dose group(TCM-M) and TCM high-dose group(TCM-H) group.Chinese herbal medicine of supplementing Qi and activating blood circulation including ginsenosides combined with ligustrazine(TMP) were used as intervention drugs.The study observed the effect of drugs on IR,serum lipid,inflammation,stress,AS and SREBP-1 c related molecules.The results showed that fasting blood glucose in TCM-H group decreased compared with other experimental groups(P<0.05).HDL-C level in betulin group,WM group,TCM-H group was higher than that in CIH group(P<0.05).LDL-C level in TCM-M group,TCM-H group is lower than that in CIH group(P<0.05).The level of CRP in CIH group was higher than that in other groups(P<0.05).The level of SOD in TCM-H group was higher than that in CIH group(P<0.05).NC group and CIH group showed obvious AS aortic plaque,while betulin group,WM group,TCM-H group showed reduction in AS plaque(P<0.05).For descending aorta,AS plaque in CIH group was multiple and large,while less and smaller in WM group and TCM-H(P<0.05).The expression of SREBP-1 c and FAS in aorta and skeletal muscle in TCM-H group was lower than that in CIH group(P<0.05).In aorta,the expression of TNF-α and CD106(VCAM-1) was lower in TCM-H group than that in CIH group(P<0.05).In aorta,skeletal muscle and liver,the level of p-IRS-1 in TCM-H group was significantly higher than that in CIH group(P<0.05).In aorta and liver,the expression of HIF-1α in TCM-H group was lower than that in CIH group(P<0.05).The study demonstrated that combination ginsenosides with TMP could improve IR and serum lipid level and inhibit inflammation and oxidative stress as well as ultimately alleviate AS to some extent.And the mechanism of its interventional effects might be related to the inhibition of CIH-induced upregulation of SREBP-1 c related molecules.
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Aterosclerosis/tratamiento farmacológico , Circulación Sanguínea/efectos de los fármacos , Medicamentos Herbarios Chinos/farmacología , Resistencia a la Insulina , Qi , Animales , Ginsenósidos/farmacología , Hipoxia/patología , Ratones , Ratones Noqueados para ApoE , Pirazinas/farmacología , Distribución AleatoriaRESUMEN
Ingestion of foreign bodies is very common in clinical practice. However, gastrointestinal perforation caused by a foreign body is rare, as most foreign bodies can pass the alimentary tract spontaneously or be removed endoscopically. Ingesting a foreign body causes gastrointestinal tract perforation in less than 1% of cases that require surgery. In the past, the literature about gastrointestinal tract perforation caused by foreign bodies had been widely reported worldwide. However, the case of foreign bodies causing gastrointestinal perforation without significant abdominal infection was rarely documented. A 47-year-old woman presented with intermittent left lower abdominal pain associated with a mass for 1 month and had no other symptoms. Laparotomy was performed after clinical assessment. During the operation, a local inflammatory mass that adhered to the abdominal wall, part of the small intestine, and sigmoid colon was found in the left lower quarter of the abdominal cavity. The surrounding intestinal wall was edematous. There were two bony foreign bodies in it. Postoperative pathology suggested an inflammatory mass. A foreign body rarely migrates into the abdominal cavity without symptoms that may be related to the omentum's slow perforation process and good function. The best treatment is surgery and using appropriate antibiotics.
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Rhizosphere microbes play critical roles for plant's growth and health. Among them, the beneficial rhizobacteria have the potential to be developed as the biofertilizer or bioinoculants for sustaining the agricultural development. The efficient rhizosphere colonization of these rhizobacteria is a prerequisite for exerting their plant beneficial functions, but the colonizing process and underlying mechanisms have not been thoroughly reviewed, especially for the nonsymbiotic beneficial rhizobacteria. This review systematically analyzed the root colonizing process of the nonsymbiotic rhizobacteria and compared it with that of the symbiotic and pathogenic bacteria. This review also highlighted the approaches to improve the root colonization efficiency and proposed to study the rhizobacterial colonization from a holistic perspective of the rhizosphere microbiome under more natural conditions.
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Alphaproteobacteria , Raíces de Plantas , Bacterias , Raíces de Plantas/microbiología , Rizosfera , Microbiología del Suelo , SimbiosisRESUMEN
The multispecies biofilm is a naturally occurring and dominant lifestyle of bacteria in nature, including in rhizosphere soil, although the current understanding of it is limited. Here, we provide an approach to rapidly establish synergistic multispecies biofilm communities. The first step is to extract cells from rhizosphere soil using the differential centrifugation method. Afterward, these soil cells are inoculated into the culture medium to form pellicle biofilm. After 36 h of incubation, the bacterial composition of the biofilm and the solution underneath are determined using the 16S rRNA gene amplicon sequencing method. Meanwhile, high-throughput bacterial isolation from pellicle biofilm is conducted using the limiting dilution method. Then, the top 5 bacterial taxa are selected with the highest abundance in the 16S rRNA gene amplicon sequencing data (pellicle biofilm samples) for further use in constructing multispecies biofilm communities. All combinations of the 5 bacterial taxa were quickly established using a 24-well plate, selected for the strongest biofilm formation ability by the crystal violet staining assay, and quantified by qPCR. Finally, the most robust synthetic bacterial multispecies biofilm communities were obtained through the methods above. This methodology provides informative guidance for conducting research on rhizosphere multispecies biofilm and identifying representative communities for studying the principles governing interactions among these species.
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Biopelículas , ARN Ribosómico 16S , Rizosfera , Microbiología del Suelo , Biopelículas/crecimiento & desarrollo , ARN Ribosómico 16S/genética , Bacterias/genética , Bacterias/aislamiento & purificación , Bacterias/clasificación , Fenómenos Fisiológicos BacterianosRESUMEN
IMPORTANCE: Co-occurrence network analysis is an effective tool for predicting complex networks of microbial interactions in the natural environment. Using isolates from a rhizosphere, we constructed multi-species biofilm communities and investigated co-occurrence patterns between microbial species in genome-scale metabolic models and in vitro experiments. According to our results, metabolic exchanges and resource competition may partially explain the co-occurrence network analysis results found in synthetic bacterial biofilm communities.
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Bacterias , Biopelículas , Biomasa , Bacterias/genética , Interacciones Microbianas , AmbienteRESUMEN
Background: N6-methyladenosine (m6A) modification is a critical epigenetic modification in eukaryotes and involves several biological processes and occurrences of diseases. However, the roles and regulatory mechanisms of m6A regulators in osteoporosis (OP) remain unclear. Thus, the purpose of this study is to explore the roles and mechanisms of m6A regulators in OP. Methods: The mRNA and microRNA (miRNA) expression profiles were respectively obtained from GSE56815, GSE7158, and GSE93883 datasets in Gene Expression Omnibus (GEO). The differential expression of 21 m6A regulators between high-bone mineral density (BMD) and low-BMD women was identified. Then, a consensus clustering of low-BMD women was performed based on differentially expressed (DE)-m6A regulators. The m6A-related differentially expressed genes (DEGs), the differentially expressed miRNAs (DE-miRNAs), and biological functions were investigated. Moreover, a weighted gene co-expression network analysis (WGCNA) was constructed to identify the OP-related hub modules, hub genes, and the functional pathways. Then, an m6A regulator-target-pathway network and the competing endogenous RNA (ceRNA) network in key modules were constructed. A least absolute shrinkage and selection operation (LASSO) Cox regression model and a Support Vector Machine-Recursive Feature Elimination (SVM-RFE) model were constructed to identify the candidate genes for OP prediction. The receiver operator characteristic (ROC) curves were used to validate the performances of predictive models and candidate genes. Results: A total of 10,520 DEGs, 13 DE-m6A regulators, and 506 DE-miRNAs between high-BMD and low-BMD women were identified. Two m6A-related subclusters with 13 DE-m6A regulators were classified for OP. There were 5,260 m6A-related DEGs identified between two m6A-related subclusters, the PI3K-Akt, MAPK, and immune-related pathways, and bone metabolism was mainly enriched in cluster 2. Cell cycle-related pathways, RNA methylation, and cell death-related pathways were significantly involved in cluster 1. Five modules were identified as key modules based on WGCNA, and an m6A regulator-target gene-pathway network and the ceRNA network were constructed in module brown. Moreover, three m6A regulators (FTO, YTHDF2, and CBLL1) were selected as the candidate genes for OP. Conclusion: M6A regulators play an important role in the occurrences and diagnosis of OP.
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MicroARNs , Osteoporosis , Dioxigenasa FTO Dependiente de Alfa-Cetoglutarato , Biomarcadores , Femenino , Redes Reguladoras de Genes , Humanos , Fosfatidilinositol 3-Quinasas , Ubiquitina-Proteína LigasasRESUMEN
Arabidopsis Casparian strip membrane domain proteins (CASPs) form a transmembrane scaffold to recruit lignin biosynthetic enzymes for Casparian strip (CS) formation. Rice is a semi-aquatic plant with a more complex root structure than Arabidopsis to adapt its growing conditions, where the different deposition of lignin and suberin is crucial for adaptive responses. Here, we observed the structure of rice primary and small lateral roots (SLRs), particularly the deposition patterns of lignin and suberin in wild type and Oscasp1 mutants. We found that the appearance time and structure of CS in the roots of rice are different from those of Arabidopsis and observed suberin deposition in the sclerenchyma in wild type roots. Rice CASP1 is highly similar to AtCASPs, but its expression is concentrated in SLR tips and can be induced by salt stress especially in the steles. The loss of OsCASP1 function alters the expression of the genes involved in suberin biosynthesis and the deposition of suberin in the endodermis and sclerenchyma and leads to delayed CS formation and uneven lignin deposition in SLRs. These different depositions may alter nutrient uptake, resulting in ion imbalance in plant, withered leaves, fewer tillers, and reduced tolerance to salt stress. Our findings suggest that OsCASP1 could play an important role in nutrient homeostasis and adaptation to the growth environment.
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Trophic interactions play a central role in driving microbial community assembly and function. In gut or soil ecosystems, successful inoculants are always facilitated by efficient colonization; however, the metabolite exchanges between inoculants and resident bacteria are rarely studied, particularly in the rhizosphere. Here, we used bioinformatic, genetic, transcriptomic, and metabonomic analyses to uncover syntrophic cooperation between inoculant (Bacillus velezensis SQR9) and plant-beneficial indigenous Pseudomonas stutzeri in the cucumber rhizosphere. We found that the synergistic interaction of these two species is highly environmental dependent, the emergence of syntrophic cooperation was only evident in a static nutrient-rich niche, such as pellicle biofilm in addition to the rhizosphere. Our results identified branched-chain amino acids (BCAAs) biosynthesis pathways are involved in syntrophic cooperation. Genome-scale metabolic modeling and metabolic profiling also demonstrated metabolic facilitation among the bacterial strains. In addition, biofilm matrix components from Bacillus were essential for the interaction. Importantly, the two-species consortium promoted plant growth and helped plants alleviate salt stress. In summary, we propose a mechanism in which synergic interactions between a biocontrol bacterium and a partner species promote plant health.
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Bacillus , Microbiota , Pseudomonas stutzeri , Bacillus/genética , Bacillus/metabolismo , Raíces de Plantas/microbiología , Pseudomonas stutzeri/genética , Rizosfera , Microbiología del SueloRESUMEN
Understanding the driving forces and intrinsic mechanisms of microbial competition is a fundamental question in microbial ecology. Despite the well-established negative correlation between exploitation competition and phylogenetic distance, the process of interference competition that is exemplified by antagonism remains controversial. Here, we studied the genus Bacillus, a commonly recognized producer of multifarious antibiotics, to explore the role of phylogenetic patterns of biosynthetic gene clusters (BGCs) in mediating the relationship between antagonism and phylogeny. Comparative genomic analysis revealed a positive association between BGC distance and phylogenetic distance. Antagonistic tests demonstrated that the inhibition phenotype positively correlated with both phylogenetic and predicted BGC distance, especially for antagonistic strains possessing abundant BGCs. Mutant-based verification showed that the antagonism was dependent on the BGCs that specifically harbored by the antagonistic strain. These findings highlight that BGC-phylogeny coherence regulates the positive correlation between congeneric antagonism and phylogenetic distance, which deepens our understanding of the driving force and intrinsic mechanism of microbial interactions.
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Bacillus , Antibacterianos/farmacología , Bacillus/genética , Vías Biosintéticas/genética , Familia de Multigenes , FilogeniaRESUMEN
Multidrug and toxic compound extrusion (MATE) proteins comprise the most recently identified family of multidrug transporters. In plants, the numbers of MATE proteins has undergone a remarkable expansion, underscoring the importance of these transporters within this kingdom. Here, we describe the identification and characterization of Activated Disease Susceptibility 1 (ADS1) which encodes a putative MATE transport protein. An activation tagging screen uncovered the ads1-Dominant (ads1-D) mutant, which was subsequently characterized by molecular, genetic and biochemical approaches. The ads1-D mutant was compromised in both basal and nonhost resistance against microbial pathogens. Further, plant defence responses conferred by RPS4 were also disabled in ads1-D plants. By contrast, depletion of ADS1 transcripts by RNA-interference (RNAi) promoted basal disease resistance. Unexpectedly, ads1-D plants were found to constitutively accumulate reactive oxygen intermediates (ROIs). However, analysis of ads1-D Arabidopsis thaliana respiratory burst oxidase (atrboh) double and triple mutants indicated that an increase in ROIs did not impact ads1-D-mediated disease susceptibility. Our findings imply that ADS1 negatively regulates the accumulation of the plant immune activator salicylic acid (SA) and cognate Pathogenesis-Related 1 (PR1) gene expression. Collectively, these data highlight an important role for MATE proteins in the establishment of plant disease resistance.
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Enfermedades de las Plantas/genética , Enfermedades de las Plantas/microbiología , Proteínas de Plantas/genética , Botrytis/metabolismo , Resistencia a la Enfermedad , Susceptibilidad a Enfermedades , Regulación de la Expresión Génica de las Plantas , Genes de Plantas , Proteínas de Plantas/metabolismo , Pseudomonas syringae/metabolismo , Ácido Salicílico/metabolismoRESUMEN
The study of the reaction between plutonium and nitrogen is helpful in further understanding the interaction between plutonium and air molecules. Currently, there is no research on the microscopic reaction mechanism of plutonium nitridation reactions. Therefore, the microscopic mechanism of the Pu with N2 gas phase reaction is explored in this study, based on density functional theory (DFT) using different basis functions. In this paper, the geometry of stationary points on the potential energy surface is optimized. In addition, the transition states are verified by frequency analysis and intrinsic reaction coordination (IRC). Finally, we obtained the reaction potential energy curve and micro reaction pathways. Analysis of the reaction mechanism shows that the reaction of Pu with N2 has two pathways. Pathway 1 (Pu + N2 â R1 â TS1 â PuN2) has a T-shaped transition state and pathway 2 (Pu + N2 â R2 â TS2 â PuN + N) has an L-shaped transition state. Both transition states have only one imaginary frequency. According to the comparison of the energy at each stagnation point along the two pathways, and the heat energy emitted by the two reaction paths, we found that pathway 1 is the main reaction pathway. The nature of Pu-N bonding evolution along the pathways was studied by atoms in molecules (AIM) and electron localization function (ELF) topological approaches. In order to analyze the role of the plutonium atom 5f orbital in the reaction, the variation in density state along the pathways was measured. Results show that the 5f orbital mainly contributes to the formation of Pu-N bonds, and the influence of temperature on the reaction rate is revealed by calculating the rate constants of the two reaction pathways.
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In this study, novel orally disintegrating tablets (ODTs) with multi-channel structure were designed to provide a rapid disintegration and subsequently drug dissolution. The ODTs were prepared using conventional wet compression through perforating channels with a special multi-channel mold. A modified sieve method was used in disintegration test as a quick screening tool during formulation evaluation. Moreover, physical properties, in vitro and in vivo disintegration time, dissolution rate and mouthfeel were also evaluated. The results demonstrated that developed multi-channel ODTs had good physical parameters, in vitro/in vivo correlation (IVIVC) of disintegration time and acceptable mouthfeel and dissolution. It also revealed that the presence of channels could accelerate the disintegration of ODTs because the channels could shorten the distance of water penetration and increased the specific surface area, resulting in a significant reduction in disintegration time. Above all, the introduction of novel multi-channel ODTs provided an alternative preparation method for ODTs and achieved good disintegration characteristics.
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Comprimidos/química , Administración Oral , Composición de Medicamentos/métodos , Liberación de Fármacos/efectos de los fármacos , Excipientes/química , Solubilidad/efectos de los fármacosRESUMEN
OBJECTIVE: The aim of this study was to establish a 3T3-L1 adipocyte model and ApoE-/- mouse model of intermittent hypoxia (IH) composite abnormal glucose metabolism (AGM) in vitro and in vivo and explore their synergistic damage effect leading to atherosclerosis (AS) and the influence of SREBP-1 signaling molecule-related mechanisms. METHODS: Mature 3T3-L1 adipocytes were cultured with complete culture medium containing DEX 1 × 106 mol/L for 96 h to establish an AGM-3T3-L1 adipocyte model. Then, AGM-3T3-L1 adipocytes were treated with IH for 0 cycles, 2 cycles, 4 cycles, 8 cycles, 16 cycles, and 32 cycles and sustained hypoxia (SH). ApoE-/- mice were treated with high-fat diet and injection of STZ solution to establish an AGM-ApoE-/- mouse model. A total of 16 AGM-ApoE-/- mice were randomly and averagely divided into the normoxic control group (NC) and model group (CIH). AGM-ApoE-/- mice of the CIH group were treated with IH, which meant that the oxygen concentration fell to 10 ± 0.5% in the first 90 seconds of one cycle and then increased to 21 ± 0.5% in the later 90 seconds, continuous for eight hours per day (09 : 00-17 : 00) with a total of eight weeks. Eight C57BL/6J mice were used as the blank control group (Con) which was fed with conventional diet. qPCR and Western blotting were used to detect the expression level of SREBP-1c, FAS, and IRS-1. Oil Red O staining was used to compare the plaque of the aorta among each mouse group. RESULTS: As a result, within 32 cycles of IH, mRNA and protein expression levels of SREBP-1c and FAS in AGM-3T3-L1 adipocytes were elevated with the increase in IH cycles; the mRNA expression of IRS-1 was decreased after IH 32 cycles and lower than that of the SH group. For the study in vivo, Oil Red O staining showed a more obvious AS aortic plaque in the CIH group. After CIH treatment of 4 w and 8 w, fasting blood glucose (FBG) of the NC group and CIH group was higher than that of the Con group, and the insulin level of the CIH group was higher than that of the Con group after IH treatment of 8 w. The expressions of the IRS-1 mRNA level in the aorta, skeletal muscle, and liver of the CIH group were lower than those in the Con group. The mRNA and protein expression of SREBP-1c and its downstream molecule FAS in the aorta, skeletal muscle, and liver significantly enhanced in the CIH group in contrast with those in the Con group. CONCLUSION: The CIH composite AGM could promote the progress of AS, which might be related to the modulation of the expression of SREBP-1-related molecular pathways.
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Aterosclerosis/metabolismo , Hipoxia de la Célula/fisiología , Glucosa/metabolismo , Apnea Obstructiva del Sueño/complicaciones , Proteína 1 de Unión a los Elementos Reguladores de Esteroles/metabolismo , Animales , Modelos Animales de Enfermedad , Masculino , Ratones , Apnea Obstructiva del Sueño/patologíaRESUMEN
Bacillus spp. produce a wide range of secondary metabolites, including antibiotics, which have been well studied for their antibacterial properties but less so as signaling molecules. Previous results indicated that the lipopeptide bacillomycin D is a signal that promotes biofilm development of Bacillus velezensis SQR9. However, the mechanism behind this signaling is still unknown. Here, we show that bacillomycin D promotes biofilm development by promoting the acquisition of iron. Bacillomycin D promotes the transcription of the iron ABC transporter FeuABC by binding to its transcription factor, Btr. These actions increase intracellular iron concentration and activate the KinB-Spo0A-SinI-SinR-dependent synthesis of biofilm matrix components. We demonstrate that this strategy is beneficial for biofilm development and competition with the Pseudomonas fluorescens PF-5. Our results unravel an antibiotic-dependent signaling mechanism that links iron acquisition to biofilm development and ecological competition.
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Antibacterianos/farmacología , Péptidos Catiónicos Antimicrobianos/farmacología , Bacillus/fisiología , Proteínas Bacterianas/metabolismo , Biopelículas/crecimiento & desarrollo , Hierro/metabolismo , Bacillus/efectos de los fármacos , Proteínas Bacterianas/genética , Biopelículas/efectos de los fármacos , Transporte Biológico/efectos de los fármacos , Modelos Biológicos , Mutación/genética , Operón/genética , Oxidación-Reducción , Unión Proteica/efectos de los fármacos , Pseudomonas fluorescens/efectos de los fármacos , Especificidad de la Especie , Factores de Transcripción/metabolismo , Regulación hacia Arriba/efectos de los fármacosRESUMEN
Efficient removal of radioactive 90Sr from nuclear waste solutions and natural water systems is of vital importance due to its radioactive nature and high mobility. We present here an anionic layered compound (NC4H12)(NC2H8)2[In3(pydc)6]·13.1H2O (SZ-6; pydc = 2,5-pyridinedicarboxylic acid) with the potential remediation ability towards radioactive Sr2+ from seawater. This material exhibits excellent ß and γ radiation resistance both in air and in aqueous solutions. Besides, this material could maintain its structural integrity in real seawater for 77 days. The adsorption experiment results show that SZ-6 exhibits superior Sr2+ removal capability over a wide pH range from 4 to 12 with fast adsorption kinetics and high selectivity. The effective removal of 90Sr from real seawater was demonstrated as well. Our results strongly suggest the potential application of SZ-6 for selectively capturing radionuclides in natural water systems.