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KEY MESSAGE: GWAS identified 347 QTLs associated with eight traits related to nitrogen use efficiency in a 389-count wheat panel. Four novel candidate transcription factor genes were verified using qRT-PCR. Nitrogen is an essential nutrient for plants that determines crop yield. Improving nitrogen use efficiency (NUE) should considerably increase wheat yield and reduce the use of nitrogen fertilisers. However, knowledge on the genetic basis of NUE during wheat maturity is limited. In this study, a diversity panel incorporating 389 wheat accessions was phenotyped for eight NUE-related agronomic traits across five different environments. A total of 347 quantitative trait loci (QTLs) for low nitrogen tolerance indices (ratio of agronomic characters under low and high nitrogen conditions) were identified through a genome-wide association study utilising 397,384 single nucleotide polymorphisms (SNPs) within the MLM (Q + K) model, including 11 stable QTLs. Furthermore, 69 candidate genes were predicted for low nitrogen tolerance indices of best linear unbiased predictions values of the eight studied agronomic traits, and four novel candidate transcription factors (TraesCS5A02G237500 for qFsnR5A.2, TraesCS5B02G384500 and TraesCS5B02G384600 for qSLR5B.1, and TraesCS3B02G068800 for qTKWR3B.1) showed differing expression patterns in contrasting low-nitrogen-tolerant wheat genotypes. Moreover, the number of favourable marker alleles calculated using NUE that were significantly related to SNP in accessions decreased over the decades, indicating a decline in the NUE of the 389 wheat varieties. These findings denote promising NUE markers that could be useful in breeding high-NUE wheat varieties, and the candidate genes could further detail the NUE-related regulation network in wheat.
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Estudio de Asociación del Genoma Completo , Triticum , Triticum/genética , Triticum/metabolismo , Nitrógeno/metabolismo , Fitomejoramiento , Sitios de Carácter Cuantitativo , Fenotipo , Polimorfismo de Nucleótido SimpleRESUMEN
The objective of this study was to investigate antibacterial activities and action mode of alkyl gallates against three food-related bacteria. Results show that the length of the alkyl chain plays a critical role in eliciting their antibacterial activities and octyl gallate (GAC8) exhibited an outstanding bactericidal effect against these strains. A possible bactericidal mechanism of GAC8 against E. coli was fully elucidated by analyzing associated changes in cellular functions of E. coli, including assessments of membrane modification and intracellular oxidation state. Our data strongly suggested that GAC8 functions outside and inside the bacterial membrane and causes increased intracellular reactive oxygen species (hydroxyl radicals) and subsequent oxidative damage. We demonstrated that the hydroxyl radical formation induced by GAC8 is the end product of an oxidative damage cellular death pathway involving a transient depletion of NADH, the tricarboxylic acid cycle, intrinsic redox cycling activities, and stimulation of the Fenton reaction. Also, chitosan-based edible films containing GAC8 have unique superiorities for icefish preservation at 4 °C. This research highlights the effectiveness of GAC8 as an attractive antibacterial, which possesses both antioxidant and antibacterial activities and can be used as a multifunctional food additive combined with the benefit of active packaging for food preservations.
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Antibacterianos/farmacología , Ésteres/farmacología , Conservación de Alimentos/métodos , Conservantes de Alimentos/farmacología , Ácido Gálico/análogos & derivados , Animales , China , Escherichia coli/efectos de los fármacos , Escherichia coli/crecimiento & desarrollo , Escherichia coli/metabolismo , Peces/microbiología , Conservación de Alimentos/instrumentación , Ácido Gálico/farmacología , Pruebas de Sensibilidad Microbiana , Estrés Oxidativo/efectos de los fármacosRESUMEN
BACKGROUND: Human demand for wheat will continue to increase together with the continuous global population growth. Agronomic traits in wheat are susceptible to environmental conditions. Therefore, in breeding practice, priority is given to QTLs of agronomic traits that can be stably detected across multiple environments and over many years. RESULTS: In this study, QTL analysis was conducted for eight agronomic traits using an introgression line population across eight environments (drought stressed and well-watered) for 5 years. In total, 44 additive QTLs for the above agronomic traits were detected on 15 chromosomes. Among these, qPH-6A, qHD-1A, qSL-2A, qHD-2D and qSL-6A were detected across seven, six, five, five and four environments, respectively. The means in the phenotypic variation explained by these five QTLs were 12.26, 9.51, 7.77, 7.23, and 8.49%, respectively. CONCLUSIONS: We identified five stable QTLs, which includes qPH-6A, qHD-1A, qSL-2A, qHD-2D and qSL-6A. They play a critical role in wheat agronomic traits. One of the dwarf genes Rht14, Rht16, Rht18 and Rht25 on chromosome 6A might be the candidate gene for qPH-6A. The qHD-1A and qHD-2D were novel stable QTLs for heading date and they differed from known vernalization genes, photoperiod genes and earliness per se genes.
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Introgresión Genética , Rasgos de la Historia de Vida , Fenotipo , Fitomejoramiento , Sitios de Carácter Cuantitativo , Triticum/genética , Ambiente , Triticum/metabolismoRESUMEN
The use of baker's yeast to reduce ethyl 2-oxo-4-phenylbutyrate (EOPB) in conventional biphasic systems is hindered by low productivities due to mass transfer resistance between the biocatalyst and the substrate partitioned into two different phases. To overcome the limitation, a new reaction-separation coupling process (RSCP) was configured in this study, based on the novel thermosensitive ionic liquids (ILs) with polyoxyethylene-tail. The solubility of ILs in common solvents was investigated to configure the unique thermosensitive ionic liquids-solvent biphasic system (TIBS) in which the reduction was performed. [(CH3)2N(C2H5)(CH2CH2O)2H][PF6] (c2) in 1,2-dimethoxyethane possesses the thermosensitive function of homogeneous at lower temperatures and phase separating at higher temperatures. The phase transformation temperature (PTT) of the mixed system of c2/1,2-dimethoxyethane (v/v, 5:18) was about 33 °C. The bioreaction takes place in a "homogeneous" liquid phase at 30 °C. At the end of each reduction run, the system temperature is increased upon to the PTT, while c2 is separated from 1,2-dimethoxyethane with turning the system into two phases. The enantiomeric excesses (e.e.) of ethyl (R)-2-hydroxy-4-phenylbutyrate ((R)-EHPB) increased about 25~30% and the yield of ethyl-2-hydroxy-4-phenylbutyrate (EHPB) increased 35% in TIBS, compared with the reduction in 1,2-dimethoxyethane. It is expected that the TIBS established in this study could provide many future opportunities in the biocatalysis.
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Líquidos Iónicos , Fenilbutiratos/metabolismo , Polietilenglicoles/química , Saccharomyces cerevisiae/metabolismo , Biocatálisis , Catálisis , Cloruros/química , Tecnología Química Verde , Solubilidad , Solventes , Estereoisomerismo , Temperatura , AguaRESUMEN
BACKGROUND: Sturgeon is popular for its nutritious value and its taste. However, sturgeon fillets are traditionally heated in 100 °C boiling water, resulting in unfavorable taste and with a negative effect on the quality. This study considered the effect of combinations of vacuum and low-temperature treatments (LTVH groups) on sturgeon fillets compared with the traditional heat treatment (TC groups). RESULTS: The results show that the LTVH groups had lower cooking-loss rates. All LTVH fillets were changed to a white color, and appeared 'done', as did the TC fillets. The LTVH and TC methods gave rise to significant differences in texture: the springiness of the LTVH groups decreased with heating time, and decreased rapidly in the TC groups (P < 0.05); hardness and chewiness increased with time and temperature in the LTVH groups, but decreased in the TC groups. More compact and denser gaps were observed in LTVH70 groups and TC groups. Less protein and lipid oxidation was evident in LTVH groups, including more myofibril protein solubility; there was less protein aggregation, fewer thiobarbituric acid reactive substance, and Schiff base. CONCLUSION: Vacuum and low-temperature treated sturgeon fillets can be served as a good alternative. This treatment caused slight tissue damage and less proteolysis and lipid oxidation, which is beneficial for the quality of aquatic products.
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Culinaria/métodos , Productos Pesqueros/análisis , Alimentos Marinos/análisis , Animales , Culinaria/instrumentación , Peces , Dureza , Humanos , Carne/análisis , Gusto , Temperatura , VacioRESUMEN
The aim of this work was to evaluate the antibacterial activities and mode of action of sucrose monolaurate (SML) with a desirable purity, synthesized by Lipozyme TL IM-mediated transesterification in the novel ionic liquid, against four pathogenic bacteria including L. monocytogenes, B. subtilis, S. aureus, and E. coli. The antibacterial activity was determined by minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and the timeâ»kill assay. SML showed varying antibacterial activity against tested bacteria with MICs and MBCs of 2.5 and 20 mM for L. monocytogenes, 2.5 and 20 mM for B. subtilis, 10 and 40 mM for S. aureus, respectively. No dramatic inhibition was observed for E. coli at 80 mM SML. Mechanism of bacterial inactivation caused by SML was revealed through comprehensive factors including cell morphology, cellular lysis, membrane permeability, K⺠leakage, zeta potential, intracellular enzyme, and DNA assay. Results demonstrated that bacterial inactivation against Gram-positive bacteria was primarily induced by the pronounced damage to the cell membrane integrity. SML may interact with cytoplasmic membrane to disturb the regulation system of peptidoglycan hydrolase activities to degrade the peptidoglycan layer and form a hole in the layer. Then, the inside cytoplasmic membrane was blown out due to turgor pressure and the cytoplasmic materials inside leaked out. Leakage of intracellular enzyme to the supernatants implied that the cell membrane permeability was compromised. Consequently, the release of K⺠from the cytosol lead to the alterations of the zeta potential of cells, which would disturb the subcellular localization of some proteins, and thereby causing bacterial inactivation. Moreover, remarkable interaction with DNA was also observed. SML at sub-MIC inhibited biofilm formation by these bacteria.
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Antibacterianos/química , Catálisis , Infecciones/tratamiento farmacológico , Sacarosa/análogos & derivados , Antibacterianos/síntesis química , Antibacterianos/farmacología , Bacillus subtilis/efectos de los fármacos , Bacillus subtilis/patogenicidad , Permeabilidad de la Membrana Celular/efectos de los fármacos , Escherichia coli/efectos de los fármacos , Escherichia coli/patogenicidad , Humanos , Infecciones/microbiología , Lipasa/química , Listeria monocytogenes/efectos de los fármacos , Pruebas de Sensibilidad Microbiana , Staphylococcus aureus/efectos de los fármacos , Staphylococcus aureus/patogenicidad , Sacarosa/química , Sacarosa/farmacologíaRESUMEN
Bioinspired photoactive composites, in terms of photodynamic inactivation, cost-effectiveness, and biosafety, are promising alternatives to antibiotics for combating bacterial infections while avoiding antibacterial resistance. However, the weak bacterial membrane affinity of the photoactive substrate and the lack of synergistic antibacterial effect remain crucial shortcomings for their antibacterial applications. Herein, we developed a hydrophobic film from food antioxidant lauryl gallate covalently functionalized chitosan (LG-g-CS conjugates) through a green radical-induced grafting reaction that utilizes synergistic bacteria capture, contact-killing, and photodynamic inactivation activities to achieve enhanced bactericidal and biofilm elimination capabilities. Besides, the grafting reaction mechanism between LG and CS in the ascorbic acid (AA)/H2O2 redox system was further proposed. The LG-g-CS films feature hydrophobic side chains and photoactive phenolic hydroxyl groups, facilitating dual bactericidal activities through bacteria capture and contact-killing via strong hydrophobic and electrostatic interactions with bacterial membranes as well as blue light (BL)-driven photodynamic bacterial eradication through the enhanced generation of reactive oxygen species. As a result, the LG-g-CS films efficiently capture and immobilize bacteria and exhibit excellent photodynamic antibacterial activity against model bacteria (Escherichia coli and Staphylococcus aureus) and their biofilms under BL irradiation. Moreover, LG-g-CS films could significantly promote the healing process of S. aureus-infected wounds. This research demonstrates a new strategy for designing and fabricating sustainable bactericidal and biofilm-removing materials with a high bacterial membrane affinity and photodynamic activity.
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Antiinfecciosos , Quitosano , Ácido Gálico/análogos & derivados , Infecciones Estafilocócicas , Humanos , Staphylococcus aureus , Quitosano/química , Peróxido de Hidrógeno/farmacología , Antiinfecciosos/química , Antibacterianos/química , Cicatrización de Heridas , Escherichia coli , BiopelículasRESUMEN
This study reported for the first time that Ascorbic acid (AA) could appreciably boost the efficiency of Octyl gallate (OG)-mediated photodynamic inactivation (PDI) on Escherichia coli and Staphylococcus aureus in planktonic and biofilm states. The combination of OG (0.075 mM) and AA (200 mM) with 420 nm blue light (212 mW/cm2) led to a >6 Log killing within only 5 min for E. coli and S. aureus and rapid eradication of biofilms. The mechanism of action appears to be the generation of highly toxic hydroxyl radicals (â¢OH) via photochemical pathways. OG was exposed to BL irradiation to generate various reactive oxygen radicals (ROS) and the addition of AA could transform singlet oxygen (1O2) into hydrogen peroxide (H2O2), which could further react with AA to generate enormous â¢OH. These ROS jeopardized bacteria and biofilms by nonspecifically attacking various biomacromolecules. Overall, this PDI strategy provides a powerful microbiological decontamination modality to guarantee safe food products.
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Ácido Ascórbico , Biopelículas , Escherichia coli , Ácido Gálico , Ácido Gálico/análogos & derivados , Luz , Staphylococcus aureus , Biopelículas/efectos de los fármacos , Ácido Ascórbico/farmacología , Ácido Ascórbico/química , Staphylococcus aureus/efectos de los fármacos , Staphylococcus aureus/fisiología , Ácido Gálico/farmacología , Ácido Gálico/química , Escherichia coli/efectos de los fármacos , Fármacos Fotosensibilizantes/farmacología , Fármacos Fotosensibilizantes/química , Antibacterianos/farmacología , Antibacterianos/química , Viabilidad Microbiana/efectos de los fármacos , Viabilidad Microbiana/efectos de la radiación , Especies Reactivas de Oxígeno/metabolismo , Plancton/efectos de los fármacos , Plancton/efectos de la radiación , Luz AzulRESUMEN
The high osmolarity glycerol (HOG) signaling pathway is crucial for yeast to cope with high osmolarity. Here, we showed that Saccharomyces cerevisiae rice wine isolates exhibited higher tolerance to osmotic stress, which was associated with the evolution of HOG pathway genes. Phylogenetic analysis of HOG genes revealed that Chinese rice wine strains were closely related to sake strains, indicating a common origin of rice wine strains. The DNA sequence diversity analysis showed that higher levels of polymorphism tended to accumulate on the osmosensor genes (MSB2 and SLN1), suggesting that most changes in a signaling transduction pathway were concentrated in the receptors. Moreover, the rapid evolution of osmosensors (Sln1/Msb2) and transcription factor (Msn4) might experience positive selection. Our results imply that the evolution of HOG pathway genes in S. cerevisiae rice wine strains is associated with their adaptation to high osmotic environments.
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Evolución Molecular , Proteínas Quinasas Activadas por Mitógenos/genética , Oryza/genética , Polimorfismo Genético , Proteínas de Saccharomyces cerevisiae/genética , Transducción de Señal/genética , Vino , Variación Genética , Proteínas Quinasas Activadas por Mitógenos/fisiología , Oryza/química , Filogenia , Proteínas de Saccharomyces cerevisiae/fisiología , Equilibrio Hidroelectrolítico/genética , Equilibrio Hidroelectrolítico/fisiologíaRESUMEN
Trichome plays an important role in heat dissipation, cold resistance, water absorption, protection of leaves from mechanical damage, and direct exposure to ultraviolet rays. It also plays an important role in the photosynthesis, transpiration, and respiration of plants. However, the genetic basis of trichome traits is not fully understood in wheat. In this study, wheat DH population (Hanxuan 10 × Lumai 14) was used to map quantitative trait loci (QTL) for trichome traits in different parts of flag leaf at 10 days after anther with growing in Zhao County, Hebei Province, and Taigu County, Shanxi Province, respectively. The results showed that trichome density (TD) was leaf center > leaf tip > leaf base and near vein > middle > edge, respectively, in both environments. The trichome length (TL) was leaf tip > leaf center > leaf base and edge > middle > near vein. Significant phenotypic positive correlations were observed between the trichome-related traits of different parts. A total of 83 QTLs for trichome-related traits were mapped onto 18 chromosomes, and each one accounted for 2.41 to 27.99% of the phenotypic variations. Two QTL hotspots were detected in two marker intervals: AX-95232910~AX-95658735 on 3A and AX-94850949~AX-109507404 on 7D. Six possible candidate genes (TraesCS3A02G406000, TraesCS3A02G414900, TraesCS3A02G440900, TraesCS7D02G145200, TraesCS7D02G149200, and TraesCS7D02G152400) for trichome-related traits of wheat leaves were screened out according to their predicted expression levels in wheat leaves. The expression of these genes may be induced by a variety of abiotic stresses. The results provide the basis for further validation and functional characterization of the candidate genes.
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Sitios de Carácter Cuantitativo , Triticum , Sitios de Carácter Cuantitativo/genética , Triticum/genética , Tricomas/genética , Transporte Biológico , Hojas de la Planta/genéticaRESUMEN
Elongator complexes (ELPs) are the protein complexes that promote transcription through histone acetylation in eukaryotic cells and interact with elongating RNA polymerase II (RNAPII). ELPs' role in plant growth and development, signal transduction, and response to biotic and abiotic stresses have been confirmed in model plants. However, the functions of the wheat ELP genes are not well documented. The present study identified 18 members of the ELPs from the wheat genome with a homology search. Further, bioinformatics and transcription patterns in response to different stress conditions were analyzed to dissect their potential regulatory mechanisms in wheat. Gene duplication analysis showed that 18 pairs of ELP paralogous genes were derived from segmental duplication, which was divided into six clades by protein phylogenetic and cluster analysis. The orthologous analysis of wheat TaELP genes showed that TaELP genes may have evolved from orthologous genes of other plant species or closely related plants. Moreover, a variety of cis-acting regulatory elements (CAREs) related to growth and development, hormone response, and biotic and abiotic stresses were identified in the TaELPs' promoter regions. The qRT-PCR analysis showed that the transcription of TaELPs was induced under hormone, salt, and drought stress and during leaf senescence. The TaELP2 gene was silenced with BSMV-VIGS, and TaELP2 was preliminarily verified to be involved in the regulation of wheat leaf senescence. Overall, TaELP genes might be regulated by hormone signaling pathways and response to abiotic stress and leaf senescence, which could be investigated further as potential candidate genes for wheat abiotic stress tolerance and yield improvement.
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While photodynamic inactivation (PDI) has emerged as a novel sterilization strategy for drinking water treatment that recently attracted tremendous attention, its efficiency needs to be further improved. In this study, we aimed to clarify the ultraefficient mechanism by which potassium iodide (KI) potentiates octyl gallate (OG)-mediated PDI against bacteria and biofilms in water. When OG (0.15 mM) and bacteria were exposed to blue light (BL, 420 nm, 210 mW/cm2), complete sterilization (>7.5 Log cfu/mL of killing) was achieved by the addition of KI (250 mM) within only 5 min (63.9 J/cm2). In addition, at lower doses of OG (0.1 mM) with KI (100 mM), the biofilm was completely eradicated within 10 min (127.8 J/cm2). The KI-potentiated mechanism involves in situ rapid photogeneration of a multitude of reactive oxygen species, especially hydroxyl radicals (â¢OH), reactive iodine species, and new photocytocidal substances (quinone) by multiple photochemical pathways, which led to the destruction of cell membranes and membrane proteins, the cleavage of genomic DNA and extracellular DNA within biofilms, and the degradation of QS signaling molecules. This multitarget synergistic strategy provided new insights into the development of an environmentally friendly, safe, and ultraefficient photodynamic drinking water sterilization technology.
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Agua Potable , Yoduro de Potasio , Yoduro de Potasio/farmacología , Bacterias/genética , BiopelículasRESUMEN
Drought is one of the most severe abiotic stresses that influence wheat production across the globe. Understanding the molecular regulatory network of wheat in response to drought is of great importance in molecular breeding. Noncoding RNAs influence plant development and resistance to abiotic stresses by regulating gene expression. In this study, whole-transcriptome sequencing was performed on the seedlings of two wheat varieties with contrasting levels of drought tolerance under drought and control conditions to identify long noncoding RNAs (lncRNAs), micro RNAs (miRNAs), and mRNAs related to drought stress and explore the potential lncRNA-miRNA-mRNA regulatory modules in controlling wheat drought stress response. A total of 1515 differentially expressed lncRNAs (DELs), 209 differentially expressed miRNAs (DEMs), and 20462 differentially expressed genes (DEGs) were identified. Of the 20462 DEGs, 1025 were identified as potential wheat drought resistance-related DEGs. Based on the regulatory relationship and expression patterns of DELs, DEMs, and DEGs, 10 DEL-DEM-DEG regulatory modules related to wheat drought stress response were screened, and preliminary expression verification of two important candidate modules was performed. Our results revealed the possible roles of lncRNA-miRNA-mRNA modules in regulatory networks related to drought tolerance and provided useful information as valuable genomic resources in molecular breeding of wheat.
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The photosynthesis of wheat glumes makes important contributions to the yield. Stomata play a crucial role in regulating photosynthesis and transpiration in plants. However, the genetic base of wheat glume stomata is not fully understood. In this study, stomatal length (SL), stomatal width (SW), stomatal density (SD), potential conductance index (PCI) of stomata, stomatal area (SA), and stomatal relative area (SRA) were measured in different parts of wheat glumes from a doubled haploid (DH) population and their parents. Quantitative trait loci (QTLs) of these traits were anchored on a high-density genetic linkage map of the DH population. A total of 61 QTLs for stoma-related traits were mapped onto 16 chromosomes, and each one accounted for 3.63 to 19.02% of the phenotypic variations. Two QTL hotspots were detected in two marker intervals, AX-109400932â¼AX-110985652 and AX-108972184â¼AX-108752564, on chromosome 6A. Five possibly candidate genes (TraesCS6A02G105400, TraesCS6A02G106400, TraesCS6A02G115100, TraesCS6A02G115400, and TraesCS6A02G116200) for stoma-related traits of wheat glumes were screened out , according to their predicted expression levels in wheat glumes or spikes. The expression of these genes may be induced by a variety of abiotic stresses. These findings provide insights for cloning and functional characterization of stoma-related candidate genes in wheat glumes.
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Sitios de Carácter Cuantitativo , Triticum , Sitios de Carácter Cuantitativo/genética , Triticum/genética , Mapeo Cromosómico , Fenotipo , Estudios de Asociación GenéticaRESUMEN
A series of alkyl gallates were evaluated for the antibacterial activity against two common Gram-negative foodborne bacteria (Pseudomonas fluorescens and Vibrio parahaemolyticus) associated with seafood. The length of the alkyl chain plays a pivotal role in eliciting their antibacterial activities and octyl gallate (OG) exerted an excellent inhibitory efficacy. To extend the aqueous solubility, stability, and bactericidal properties of octyl gallate (OG), an inclusion complex between OG and ß-cyclodextrin (ßCD), OG/ßCD, was prepared and identified with various methods including X-ray diffraction (XRD), differential scanning calorimeter (DSC) and Fourier transform infrared spectroscopy (FTIR). Furthermore, the enhanced inhibitory effect and potential antibacterial mechanism of OG/ßCD against two Gram-negative and Gram-positive foodborne bacteria were comprehensively investigated. The results show that OG/ßCD could function against bacteria through effectively damaging the membrane, permeating into cells, and then disturbing the activity of the respiratory electron transport chain to cause the production of high-level intracellular hydroxyl radicals. Moreover, the reinforced OG/ßCD-incorporated polylactic acid (PLA) nanofibers were fabricated using the electrospinning technique as food packaging to extend the Chinese giant salamander fillet's shelf life at 4 °C. This research highlights the antibacterial effectiveness of OG/ßCD in aqueous media, which can be used as a safe multi-functionalized food additive combined with the benefits of electrospun nanofibers to extend the Chinese giant salamander fillets shelf life by 15 d at 4 °C.
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Nanofibras , Pseudomonas fluorescens , Vibrio parahaemolyticus , beta-Ciclodextrinas , Animales , Antibacterianos/farmacología , China , Ácido Gálico/análogos & derivados , Espectroscopía Infrarroja por Transformada de Fourier , Urodelos , beta-Ciclodextrinas/farmacologíaRESUMEN
Pseudomonas fluorescens is a Gram-negative spoilage bacterium and dense biofilm producer, causing food spoilage and persistent contamination. Here, we report an ultra-efficient photodynamic inactivation (PDI) system based on blue light (BL) and octyl gallate (OG) to eradicate bacteria and biofilms of P. fluorescens. OG-mediated PDI could lead to a > 5-Log reduction of viable cell counts within 15 min for P. fluorescens. The activity is exerted through rapid penetration of OG towards the cells with the generation of a high-level toxic reactive oxygen species triggered by BL irradiation. Moreover, OG plus BL irradiation can efficiently not only prevent the formation of biofilms but also scavenge the existing biofilms. Additionally, it was shown that the combination of OG/poly(lactic acid) electrospun nanofibers and BL have great potential as antimicrobial packagings for maintaining the freshness of the salamander storge. These prove that OG-mediated PDI can provide a superior platform for eradicating bacteria and biofilm.
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Pseudomonas fluorescens , Antibacterianos , Biopelículas , Ácido Gálico/análogos & derivados , PlanctonRESUMEN
This study aimed to investigate the synergistic bactericidal activity and mechanism of dual-stage light-guided membrane and DNA-targeted photodynamic inactivation (PDI) by the combination of blue light (BL, 420 nm) and the food additive octyl gallate (OG) against Vibrio parahaemolyticus in planktonic and biofilm growth modes. While OG serves as an outstanding exogenous photosensitizer, the planktonic cells were not visibly detectable after the OG-mediated PDI treatment with 0.2 mM OG within 15 min (191.7 J/cm2), and its biofilm was nearly eradicated within 60 min (383.4 J/cm2). Gram-positive Staphylococcus aureus was more susceptible to the PDI than Gram-negative V. parahaemolyticus. The cellular wall and proteins, as well as DNA, were the vulnerable targets for PDI. The membrane integrity could be initially disrupted by OG bearing a hydrophilic head and a hydrophobic tail via transmembrane insertion. The enhancement of OG uptake due to the first-stage light-assisted photochemical internalization (PCI) promoted the accumulation of OG in cells. It further boosted the second-stage light irradiation of the photosensitizer-inducing massive cell death. Upon the second-stage BL irradiation, reactive oxygen species (ROS) generated through the OG-mediated PDI in situ could extensively deconstruct membranes, proteins, and DNA, as well as biofilms, while OG could be activated by BL to carry out photochemical reactions involving the formation of OG-bacterial membrane protein (BMP) covalent conjugates and the interactions with DNA. This dual-stage light-guided subcellular dual-targeted PDI strategy exhibits encouraging effects on the eradication of planktonic bacteria and sessile biofilms, which provides a new insight into the development of an ultraeffective antimicrobial and biofilm removing/reducing technique to improve microbiological safety in the food industry.
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Fármacos Fotosensibilizantes , Plancton , Bacterias , Biopelículas , ADN , Ácido Gálico/análogos & derivados , Fármacos Fotosensibilizantes/farmacologíaRESUMEN
Premature leaf senescence has a profound influence on crop yield and quality. Here, a stable premature senescence mutant (GSm) was obtained from the common wheat (Triticum aestivum L.) cultivar Chang 6878 by mutagenesis with ethyl methanesulfonate. The differences between the GSm mutant and its wild-type (WT) were analyzed in terms of yield characteristics, photosynthetic fluorescence indices, and senescence-related physiological parameters. RNA sequencing was used to reveal gene expression differences between GSm and WT. The results showed that the yield of GSm was considerably lower than that of WT. The net photosynthetic rate, transpiration rate, maximum quantum yield, non-photochemical quenching coefficient, photosynthetic electron transport rate, soluble protein, peroxidase activity, and catalase activity all remarkably decreased in flag leaves of GSm, whereas malondialdehyde content distinctively increased compared with those of WT. The analysis of differentially expressed genes indicated blockade of chlorophyll and carotenoid biosynthesis, accelerated degradation of chlorophyll, and diminished photosynthetic capacity in mutant leaves; brassinolide might facilitate chlorophyll breakdown and consequently accelerate leaf senescence. NAC genes positively regulated the senescence process. Compared with NAC genes, expression of WRKY and MYB genes was induced earlier in the mutant possibly due to increased levels of reactive oxygen species and plant hormones (e.g., brassinolide, salicylic acid, and jasmonic acid), thereby accelerating leaf senescence. Furthermore, the antioxidant system played a role in minimizing oxidative damage in the mutant. These results provides novel insight into the molecular mechanisms of premature leaf senescence in crops.
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Improving solubility and administration route of isoflavone formononetin (FMN) are critical factors to improve its bioavailability in the oral cavity. This study fabricated fast-dissolving nanofibers containing FMN/methyl-ß-cyclodextrin (FMN/Me-ß-CD) inclusion complex. The solubility of FMN could be increased by approximately 50 times at 20 mM aqueous Me-ß-CD. Interactions and thermodynamic parameters of the host-guest inclusion complex were studied by a fluorescence quenching method. The structure and mechanisms of the complex were further studied by molecular docking and molecular dynamics. Finally, polyvinyl-alcohol (PVA) nanofibrous webs containing the FMN/Me-ß-CD inclusion complex were fabricated by electrospinning. The dissolution test demonstrated that the FMN/Me-ß-CD/PVA nanofibers can be dissolved in artificial saliva within approximately 2 s. This study shows the potential of Me-ß-CD inclusion and electrospinning to improve solubility and administration route of isoflavones.
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Isoflavonas , Nanofibras , Portadores de Fármacos , Simulación del Acoplamiento Molecular , Alcohol Polivinílico , Polivinilos , Solubilidad , Agua , beta-CiclodextrinasRESUMEN
The digestion properties of sturgeon myofibrillar protein (MF) treated by low temperature vacuum heating (LTVH) at different processing temperatures (50, 60 and 70 °C) and times (15 and 30 min) were studied and compared with those of sturgeon MF treated by traditional cooking (TC). The results showed that as the temperature and time increased, the protein digestibility decreased, whereas the particle size and protein aggregation increased. It was observed that the band intensity of myosin heavy chain and myosin heavy chain 7 weakened; however, the band intensity of actin showed little change. MALDI-TOF-MS analysis revealed that the digested products of the samples treated by LTVH had a larger proportion of 750-1000 Da peptides than those treated by TC, which was consistent with the trend of the number of unique peptides identified in each group. Fourier transmission infrared (FT-IR) spectroscopy showed that the contents of α-helices and ß-sheets exhibited negative and positive correlations with the temperature, respectively. Overall, compared to TC, LTVH can relieve the heat stress of protein conformation, reduce protein aggregation to improve the accessibility of the protein to digestive protease, and increase digestibility.