RESUMEN
The effects of preharvest methyl jasmonate (MeJA) spray application on the physicochemical quality, metabolism of phenolics, and cell wall components in raspberries were investigated during a 10-day cold storage period. MeJA spray reduced firmness loss, decay incidence, and weight loss, while maintained higher levels of soluble solids content, ascorbic acid, anthocyanins and flavonoids in raspberries. Furthermore, MeJA application resulted in increased total pectin and protopectin levels, as well as lowered water-soluble pectin, and activities of pectin methyl esterase, polygalacturonase and cellulase enzymes. Additionally, MeJA treatment upregulated the phenylpropanoid pathway, leading to higher endogenous phenolics and activities of phenylalanine-ammonia lyase and shikimate dehydrogenase. In conclusion, preharvest MeJA spray application could be adopted to enhance the storage potential of cold-stored raspberries for 10 days by maintaining higher firmness, assuring better physicochemical quality, and increasing phenolic metabolism, while reducing cell wall hydrolysis.
Asunto(s)
Acetatos , Antioxidantes , Pared Celular , Ciclopentanos , Almacenamiento de Alimentos , Frutas , Oxilipinas , Fenoles , Rubus , Oxilipinas/farmacología , Oxilipinas/metabolismo , Pared Celular/metabolismo , Pared Celular/efectos de los fármacos , Pared Celular/química , Ciclopentanos/farmacología , Ciclopentanos/metabolismo , Fenoles/metabolismo , Antioxidantes/metabolismo , Acetatos/farmacología , Acetatos/metabolismo , Frutas/metabolismo , Frutas/química , Frutas/efectos de los fármacos , Rubus/metabolismo , Rubus/química , Conservación de Alimentos/métodos , Frío , Proteínas de Plantas/metabolismoRESUMEN
Plasmodesmata are conduits in plant cell walls that allow neighboring cells to communicate and exchange resources. Despite their central importance to plant development and physiology, our understanding of plasmodesmata is relatively limited compared to other subcellular structures. In recent years, technical advances in electron microscopy, mass spectrometry, and phylogenomics have illuminated the structure, composition, and evolution of plasmodesmata in diverse plant lineages. In parallel, forward genetic screens have revealed key signaling pathways that converge to regulate plasmodesmatal transport, including chloroplast-derived retrograde signaling, phytohormone signaling, and metabolic regulation by the conserved eukaryotic Target of Rapamycin kinase. This review summarizes our current knowledge of the structure, evolution, and regulation of plasmodesmatal transport in plants.
Asunto(s)
Pared Celular , Plantas , Plasmodesmos , Plasmodesmos/metabolismo , Pared Celular/metabolismo , Plantas/metabolismo , Transporte Biológico , Evolución Biológica , Transducción de Señal/fisiología , Comunicación Celular/fisiologíaRESUMEN
The Mycobacterium cell wall is a capsule-like structure comprising of various layers of biomolecules such as mycolic acid, peptidoglycans, and arabinogalactans, which provide the Mycobacteria a sort of cellular shield. Drugs like isoniazid, ethambutol, cycloserine, delamanid, and pretomanid inhibit cell wall synthesis by inhibiting one or the other enzymes involved in cell wall synthesis. Many enzymes present across these layers serve as potential targets for the design and development of newer anti-TB drugs. Some of these targets are currently being exploited as the most druggable targets like DprE1, InhA, and MmpL3. Many of the anti-TB agents present in clinical trials inhibit cell wall synthesis. The present article covers a systematic perspective of developing cell wall inhibitors targeting various enzymes involved in cell wall biosynthesis as potential drug candidates for treating Mtb infection.
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Antituberculosos , Proteínas Bacterianas , Pared Celular , Mycobacterium tuberculosis , Pared Celular/metabolismo , Pared Celular/efectos de los fármacos , Antituberculosos/farmacología , Antituberculosos/química , Mycobacterium tuberculosis/efectos de los fármacos , Mycobacterium tuberculosis/metabolismo , Humanos , Proteínas Bacterianas/metabolismo , Proteínas Bacterianas/antagonistas & inhibidores , Tuberculosis/tratamiento farmacológico , Oxidorreductasas/metabolismo , Oxidorreductasas/antagonistas & inhibidores , Ácidos Micólicos/metabolismo , Oxidorreductasas de Alcohol , Proteínas de Transporte de MembranaRESUMEN
Hyperspectral microscope imaging (HMI) technique was employed to assess the changes in physicochemical parameters and microstructure of 'Golden Delicious' apples flesh during storage. Four regions of interest (ROIs), including whole-cell ROI, intercellular space ROI, cytoplasm ROI, and cell wall ROI were investigated to assess their relationships with physicochemical parameters. Different ROIs presented similar vibrational profiles, but with slight differences in spectral intensity, especially in the range of 800-1000 nm. Spectral angle mapper (SAM) was applied to the HMI of apple tissues at different storage stages to clearly show the structural changes of parenchyma cells, while principal component analysis (PCA) could highlight the distribution of sugars, water and pigments in apple flesh at the cellular scale. Simultaneously with the degradation of acid-soluble pectin (ASP), middle lamella dissolution and increased intercellular space were observed using SEM and TEM. Single feature variables were used to construct linear models based on pearson correlation analysis, with R2 of 0.96 for moisture at 982 nm, 0.85 for water-soluble pectin (WSP) at 420 nm, 0.82 for L* at 946 nm, 0.77 for soluble solids content (SSC) at 484 nm, and 0.66 for firmness at 490 nm. This work demonstrated the great potential of HMI technology as a fast, accurate and efficient solution for assessing the quality of 'Golden Delicious' apples.
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Frutas , Imágenes Hiperespectrales , Malus , Pectinas , Malus/química , Frutas/química , Imágenes Hiperespectrales/métodos , Pectinas/química , Pectinas/análisis , Análisis de Componente Principal , Microscopía/métodos , Almacenamiento de Alimentos/métodos , Microscopía Electrónica de Rastreo , Pared Celular/químicaRESUMEN
BACKGROUNDS: Mycobacterium tuberculosis (Mtb), the pathogen responsible for tuberculosis, secretes a multitude of proteins that modulate the host's immune response to ensure its own persistence. The region of difference (RD) genes encoding proteins play key roles in TB immunity and pathogenesis. Nevertheless, the roles of the majority of RD-encoded proteins remain to be elucidated. OBJECTS: To elucidate the role of Rv2652c located in RD13 in Mtb on bacterial growth, bacterial survival, and host immune response. METHODS: We constructed the strain MS_Rv2652c which over-expresses Mtb RD-encoding protein Rv2652c in M. smegmatis (MS), and compared it with the wild strain in the bacterial growth, bacterial survival, virulence of Rv2652c, and determined the effect of MS_Rv2652c on host immune response in macrophages. RESULTS: Rv2652c protein is located at cell wall of MS_Rv2652c strain and also an integral component of the Mtb H37Rv cell wall. Rv2652c can enhance the resistance of recombinant MS to various stressors. Moreover, Rv2652c inhibits host proinflammatory responses via modulation of the NF-κB pathway, thereby promoting Mtb survival in vitro and in vivo. CONCLUSION: Our data suggest that cell wall protein Rv2652c plays an important role in creating a favorable environment for bacterial survival by modulating host signals and could be established as a potential TB drug target.
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Proteínas Bacterianas , Macrófagos , Mycobacterium tuberculosis , Mycobacterium tuberculosis/inmunología , Proteínas Bacterianas/metabolismo , Proteínas Bacterianas/genética , Proteínas Bacterianas/inmunología , Animales , Ratones , Macrófagos/inmunología , Macrófagos/microbiología , Macrófagos/metabolismo , Tuberculosis/inmunología , Tuberculosis/microbiología , Humanos , Interacciones Huésped-Patógeno/inmunología , Virulencia , Mycobacterium smegmatis/inmunología , Viabilidad Microbiana/inmunología , FN-kappa B/metabolismo , Ratones Endogámicos C57BL , Pared Celular/inmunología , Pared Celular/metabolismoRESUMEN
BACKGROUND: Brassica napus L. (B. napus) is susceptible to waterlogging stress during different cultivation periods. Therefore, it is crucial to enhance the resistance to waterlogging stress to achieve a high and stable yield of B. napus. RESULTS: Here we observed significant differences in the responses of two B. napus varieties in root under waterlogging stress. The sensitive variety (23651) exhibited a more pronounced and rapid reduction in cell wall thickness and root integrity compared with the tolerant variety (Santana) under waterlogging stress. By module clustering analysis based on transcriptome data, we identified that cell wall polysaccharide metabolism responded to waterlogging stress in root. It was found that pectin content was significantly reduced in the sensitive variety compared with the tolerant variety. Furthermore, transcriptome analysis revealed that the expression of two homologous genes encoding polygalacturonase-inhibiting protein 2 (PGIP2), involved in polysaccharide metabolic pathways, was highly upregulated in root of the tolerant variety under waterlogging stress. BnaPGIP2s probably confer waterlogging resistance by inhibiting the activity of polygalacturonases (PGs), which in turn reduces the degradation of the pectin backbone polygalacturonic acid. CONCLUSIONS: Our findings demonstrate that cell wall polysaccharides in root plays a vital role in response to the waterlogging stress and provide a theoretical foundation for breeding waterlogging resistance in B. napus varieties.
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Brassica napus , Pared Celular , Raíces de Plantas , Polisacáridos , Estrés Fisiológico , Brassica napus/fisiología , Brassica napus/genética , Pared Celular/metabolismo , Polisacáridos/metabolismo , Raíces de Plantas/fisiología , Regulación de la Expresión Génica de las Plantas , Proteínas de Plantas/metabolismo , Proteínas de Plantas/genética , Pectinas/metabolismo , Agua/metabolismoRESUMEN
Yeast cell wall (YCW) polysaccharides, including ß-glucans, mannans, chitins, and glycogens, can be extracted from the waste of beer industry. They are environmentally friendly, abundant, inexpensive raw materials, and have shown broad biological activities and application potentials. The exploitation of yeast polysaccharides is of great importance for environmental protection and resource utilization. This paper reviews the structural features and preparation of YCW polysaccharides. The solubility and emulsification of yeast polysaccharides and the properties of binding metal ions are presented. In addition, biological activities such as blood glucose and lipid lowering, immune regulation, antioxidant, promotion of intestinal health, and promotion of wound healing are proposed, highlighting the beneficial effects of yeast polysaccharides on human health. Through modification, the physical and chemical properties of yeast polysaccharides are changed, which emphasizes the promotion of their biological activities and properties. In addition, the food applications of yeast polysaccharides, including the food packaging film, emulsifier, thickening agent, and fat alternatives, are focused and discussed.
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Polisacáridos , Polisacáridos/química , Polisacáridos/farmacología , Saccharomyces cerevisiae/química , Levaduras/química , Humanos , Embalaje de Alimentos/métodos , Polisacáridos Fúngicos/química , Polisacáridos Fúngicos/farmacología , Emulsionantes/química , Pared Celular/químicaRESUMEN
To withstand their internal turgor pressure and external threats, most bacteria have a protective peptidoglycan (PG) cell wall. The growth of this PG polymer relies on autolysins, enzymes that create space within the structure. Despite extensive research, the regulatory mechanisms governing these PG-degrading enzymes remain poorly understood. Here, we unveil a novel and widespread control mechanism of lytic transglycosylases (LTs), a type of autolysin responsible for breaking down PG glycan chains. Specifically, we show that LD-crosslinks within the PG sacculus act as an inhibitor of LT activity. Moreover, we demonstrate that this regulation controls the release of immunogenic PG fragments and provides resistance against predatory LTs of both bacterial and viral origin. Our findings address a critical gap in understanding the physiological role of the LD-crosslinking mode in PG homeostasis, highlighting how bacteria can enhance their resilience against environmental threats, including phage attacks, through a single structural PG modification.
Asunto(s)
Pared Celular , N-Acetil Muramoil-L-Alanina Amidasa , Peptidoglicano , Peptidoglicano/metabolismo , Pared Celular/metabolismo , N-Acetil Muramoil-L-Alanina Amidasa/metabolismo , N-Acetil Muramoil-L-Alanina Amidasa/química , Proteínas Bacterianas/metabolismo , Proteínas Bacterianas/química , Escherichia coli/metabolismo , Glicosiltransferasas/metabolismo , Bacillus subtilis/metabolismoRESUMEN
Anthracnose, a fungal disease, commonly infects tea plants and severely impacts the yield and quality of tea. One method for controlling anthracnose is the application of citronellol, a plant extract that exhibits broad-spectrum antimicrobial activity. Herein, the physiological and biochemical mechanism by which citronellol controls anthracnose caused by Colletotrichum camelliae was investigated. Citronellol exhibited excellent antifungal activity based on direct and indirect mycelial growth inhibition assays, with EC50 values of 76.88 mg/L and 29.79 µL/L air, respectively. Citronellol also exhibited good control effects on C. camelliae in semi-isolated leaf experiments. Optical and scanning electron microscopy revealed that citronellol caused C. camelliae mycelia to thin, fracture, fold and deform. Transmission electron microscopy revealed that the mycelial cell walls collapsed inward and separated, and the organelles became blurred after treatment with citronellol. The sensitivity of C. camelliae to calcofluor white staining was significantly enhanced by citronellol, while PI staining showed minimal fluorescence, and the relative conductivity of mycelia were not significantly different. Under citronellol treatment, the expression levels of ß-1,3-glucanase, chitin synthase, and chitin deacetylase-related genes were significantly decreased, while the expression levels of chitinase genes were increased, leading to lower chitinase activity and increased ß-1,3-glucanase activity. Therefore, citronellol disrupted the cell wall integrity of C. camelliae and inhibited normal mycelial growth.
Asunto(s)
Monoterpenos Acíclicos , Pared Celular , Colletotrichum , Colletotrichum/efectos de los fármacos , Pared Celular/efectos de los fármacos , Pared Celular/ultraestructura , Monoterpenos Acíclicos/farmacología , Antifúngicos/farmacología , Monoterpenos/farmacología , Enfermedades de las Plantas/microbiología , Enfermedades de las Plantas/prevención & control , Micelio/efectos de los fármacos , Micelio/crecimiento & desarrollo , Micelio/ultraestructura , Fungicidas Industriales/farmacologíaRESUMEN
MAIN CONCLUSION: Four cultivars of Paeonia lactiflora pollen have a different viability after cryopreservation, and that the difference of pollen viability is related to calcium ions and cell wall deposition. Cryopreservation is a vital technique for preserving germplasm resources, offering extensive application prospects. Understanding the factors influencing pollen viability after cryopreservation is crucial for the permanent preservation and exchange of pollen resources. This study investigated pollen from four Paeonia lactiflora cultivars with varying viability after cryopreservation, aiming to determine whether calcium ions (Ca2+) and cell wall deposition affect these viability changes. The results showed that Ca2+-ATPase activity and cytoplasmic Ca2+ of all four cultivars exhibited an increasing trend after cryopreservation; the calmodulin (CaM) content varied with cultivars. Correlation analysis showed that fresh pollen viability was significantly negatively correlated with cytoplasmic Ca2+ content and positively correlated with Ca2+-ATPase activity, while pollen viability after cryopreservation exhibited a significantly negative correlation with cytoplasmic Ca2+ content and a positive correlation with CaM content. The pollen cell wall of the cultivar 'Zi Feng Chao Yang' (ZFCY), which showed increased viability after cryopreservation, contained significantly higher levels of low-temperature tolerance-related phospholipids and proteins compared to other cultivars. Additionally, all cultivars maintained a clear Ca2+ gradient at the tips of pollen tubes after cryopreservation, without significant callose accumulation. These findings suggest that differences in Ca2+ signaling and cell wall components deposition influence changes in pollen viability after cryopreservation, and the Ca2+ gradient and callose at the tip of pollen tubes are not responsible for preventing pollen tube growth.
Asunto(s)
Calcio , Pared Celular , Criopreservación , Paeonia , Polen , Pared Celular/metabolismo , Criopreservación/métodos , Calcio/metabolismo , Polen/fisiología , Paeonia/fisiología , Paeonia/metabolismo , Calmodulina/metabolismo , Supervivencia CelularRESUMEN
Bicarbonate and CO2 are essential substrates for carboxylation reactions in bacterial central metabolism. In Staphylococcus aureus, the bicarbonate transporter, MpsABC (membrane potential-generating system) is the only carbon concentrating system. An mpsABC deletion mutant can hardly grow in ambient air. In this study, we investigated the changes that occur in S. aureus when it suffers from CO2/bicarbonate deficiency. Electron microscopy revealed that ΔmpsABC has a twofold thicker cell wall thickness compared to the parent strain. The mutant was also substantially inert to cell lysis induced by lysostaphin and the non-ionic surfactant Triton X-100. Mass spectrometry analysis of muropeptides revealed the incorporation of alanine into the pentaglycine interpeptide bridge, which explains the mutant's lysostaphin resistance. Flow cytometry analysis of wall teichoic acid (WTA) glycosylation patterns revealed a significantly lower α-glycosylated and higher ß-glycosylated WTA, explaining the mutant's increased resistance towards Triton X-100. Comparative transcriptome analysis showed altered gene expression profiles. Autolysin-encoding genes such as sceD, a lytic transglycosylase encoding gene, were upregulated, like in vancomycin-intermediate S. aureus mutants (VISA). Genes related to cell wall-anchored proteins, secreted proteins, transporters, and toxins were downregulated. Overall, we demonstrate that bicarbonate deficiency is a stress response that causes changes in cell wall composition and global gene expression resulting in increased resilience to cell wall lytic enzymes and detergents.
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Bicarbonatos , Pared Celular , Staphylococcus aureus , Staphylococcus aureus/metabolismo , Staphylococcus aureus/genética , Bicarbonatos/metabolismo , Pared Celular/metabolismo , Proteínas Bacterianas/metabolismo , Proteínas Bacterianas/genética , Estrés Fisiológico , Regulación Bacteriana de la Expresión Génica , Dióxido de Carbono/metabolismoRESUMEN
Leaf angle (LA) is an important trait of plant architecture, and individuals with narrow LA can better capture canopy light under high-density planting, which is beneficial for increasing the overall yield per unit area. To study the genetic basis and molecular regulation mechanism of leaf angle in rapeseed, we carried out a series of experiments. Quantitative trait loci (QTL) mapping was performed using the RIL population, and seven QTLs were identified. Transcriptome analysis showed that the cell wall formation/biogenesis processes and biosynthesis/metabolism of cell wall components were the most enrichment classes. Most differentially expressed genes (DEGs) involved in the synthesis of lignin, xylan, and cellulose showed down-regulated expression in narrow leaf material. Microscopic analysis suggested that the cell size affected by the cell wall in the junction area of the stem and petiole was the main factor in leaf petiole angle (LPA) differences. Combining QTL mapping and RNA sequencing, five promising candidate genes BnaA01G0125600ZS, BnaA01G0135700ZS, BnaA01G0154600ZS, BnaA10G0154200ZS, and BnaC03G0294200ZS were identified in rapeseed, and most of them were involved in cell wall biogenesis and the synthesis/metabolism of cell wall components. The results of QTL, transcriptome analysis, and cytological analysis were highly consistent, collectively revealing that genes related to cell wall function played a crucial role in regulating the LA trait in rapeseed. The study provides further insights into LA traits, and the discovery of new QTLs and candidate genes is highly beneficial for genetic improvement.
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Brassica napus , Mapeo Cromosómico , Hojas de la Planta , Sitios de Carácter Cuantitativo , Brassica napus/genética , Brassica napus/metabolismo , Hojas de la Planta/genética , Hojas de la Planta/metabolismo , Regulación de la Expresión Génica de las Plantas , Análisis de Secuencia de ARN/métodos , Pared Celular/metabolismo , Pared Celular/genética , Fenotipo , Perfilación de la Expresión Génica/métodos , Genes de Plantas , TranscriptomaRESUMEN
Sulfur dioxide (SO2) is the most effective preservative for table grapes as it reduces the respiratory intensity of berries and inhibits mold growth. However, excessive SO2 causes berry abscission during storage, resulting in an economic loss postharvest. In this study, grapes were exogenously treated with SO2, SO2 + 1.5% chitosan, SO2 + 1.5% eugenol, and SO2 + eugenol-loaded chitosan nanoparticles (SN). In comparison to SO2 treatment, SN treatment reduced the berries' abscission rate by 74% while maintaining the quality of the berries. Among the treatments, SN treatment most effectively inhibited berry abscission and maintained berry quality. RNA-sequencing (RNA-seq) revealed that SN treatment promoted the expression of genes related to cell wall metabolism. Among these genes, VlCOMT was detected as the central gene, playing a key role in mediating the effects of SN. Dual luciferase and yeast one-hybrid (Y1H) assays demonstrated that VlbZIP14 directly activated VlCOMT by binding to the G-box motif in the latter's promoter, which then participated in lignin synthesis. Our results provide key insights into the molecular mechanisms underlying the SN-mediated inhibition of berry abscission and could be used to improve the commercial value of SO2-treated postharvest table grapes.
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Frutas , Regulación de la Expresión Génica de las Plantas , Lignina , Proteínas de Plantas , Factores de Transcripción , Vitis , Vitis/efectos de los fármacos , Vitis/genética , Vitis/crecimiento & desarrollo , Vitis/metabolismo , Lignina/biosíntesis , Frutas/efectos de los fármacos , Frutas/crecimiento & desarrollo , Frutas/metabolismo , Frutas/genética , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Regulación de la Expresión Génica de las Plantas/efectos de los fármacos , Factores de Transcripción/metabolismo , Factores de Transcripción/genética , Quitosano/farmacología , Dióxido de Azufre/farmacología , Pared Celular/metabolismo , Pared Celular/efectos de los fármacos , Regiones Promotoras GenéticasRESUMEN
Cotton fiber is the leading natural textile material, and fiber elongation plays an essential role in the formation of cotton yield and quality. Although a number of components in the molecular network controlling cotton fiber elongation have been reported, a lot of players still need to be functionally dissected to understand the regulatory mechanism of fiber elongation comprehensively. In the present study, an R2R3-MYB transcription factor gene, GhMYB201, was characterized and functionally verified via CRISPR/Cas9-mediated gene editing. GhMYB201 was homologous to Arabidopsis AtMYB60, and both coding genes (GhMYB201At and GhMYB201Dt) were preferentially expressed in elongating cotton fibers. Knocking-out of GhMYB201 significantly reduced the rate and duration of fiber elongation, resulting in shorter and coarser mature fibers. It was found that GhMYB201 could bind and activate the transcription of cell wall loosening genes (GhRDLs) and also ß-ketoacyl-CoA synthase genes (GhKCSs) to enhance very-long-chain fatty acid (VLCFA) levels in elongating fibers. Taken together, our data demonstrated that the transcription factor GhMYB201s plays an essential role in promoting fiber elongation via activating genes related to cell wall loosening and VLCFA biosynthesis.
Asunto(s)
Pared Celular , Fibra de Algodón , Ácidos Grasos , Regulación de la Expresión Génica de las Plantas , Gossypium , Proteínas de Plantas , Factores de Transcripción , Pared Celular/metabolismo , Pared Celular/genética , Factores de Transcripción/genética , Factores de Transcripción/metabolismo , Gossypium/genética , Gossypium/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Ácidos Grasos/metabolismo , Ácidos Grasos/biosíntesisRESUMEN
The lateral root (LR) is an essential component of the plant root system, performing important functions for nutrient and water uptake in plants and playing a pivotal role in cereal crop productivity. Nitrate (NO3-) is an essential nutrient for plants. In this study, wheat plants were grown in 1/2 strength Hoagland's solution containing 5 mM NO3- (check; CK), 0.1 mM NO3- (low NO3-; LN), or 0.1 mM NO3- plus 60 mg/L 2,3,5-triiodobenzoic acid (TIBA) (LNT). The results showed that LN increased the LR number significantly at 48 h after treatment compared with CK, while not increasing the root biomass, and LNT significantly decreased the LR number and root biomass. The transcriptomic analysis showed that LN induced the expression of genes related to root IAA synthesis and transport and cell wall remodeling, and it was suppressed in the LNT conditions. A physiological assay revealed that the LN conditions increased the activity of IAA biosynthesis-related enzymes, the concentrations of tryptophan and IAA, and the activity of cell wall remodeling enzymes in the roots, whereas the content of polysaccharides in the LRP cell wall was significantly decreased compared with the control. Fourier-transform infrared spectroscopy and atomic microscopy revealed that the content of cell wall polysaccharides decreased and the cell wall elasticity of LR primordia (LRP) increased under the LN conditions. The effects of LN on IAA synthesis and polar transport, cell wall remodeling, and LR development were abolished when TIBA was applied. Our findings indicate that NO3- starvation may improve auxin homeostasis and the biological properties of the LRP cell wall and thus promote LR initiation, while TIBA addition dampens the effects of LN on auxin signaling, gene expression, physiological processes, and the root architecture.
Asunto(s)
Regulación de la Expresión Génica de las Plantas , Ácidos Indolacéticos , Nitratos , Raíces de Plantas , Transducción de Señal , Triticum , Triticum/metabolismo , Triticum/genética , Triticum/crecimiento & desarrollo , Ácidos Indolacéticos/metabolismo , Raíces de Plantas/crecimiento & desarrollo , Raíces de Plantas/metabolismo , Raíces de Plantas/genética , Raíces de Plantas/efectos de los fármacos , Nitratos/metabolismo , Regulación de la Expresión Génica de las Plantas/efectos de los fármacos , Pared Celular/metabolismo , Proteínas de Plantas/metabolismo , Proteínas de Plantas/genética , Organogénesis de las Plantas/genética , Perfilación de la Expresión GénicaRESUMEN
Flax (Linum usitatissimum L.) is an important crop plant with pharmaceutical significance. It is described in pharmacopoeias (the United States Pharmacopeia and the European Pharmacopoeia), which confirms that it (especially the seeds) is a valuable medicinal product. Similar to flax seeds, which accumulate bioactive compounds, flax in vitro cultures are also a rich source of flavonoids, phenolics, lignans and neolignans. In the present study, flax suspension cultures after treatment of the non-pathogenic Fusarium oxysporum strain Fo47 were established and analyzed. The study examined the suitability of Fo47 as an elicitor in flax suspension cultures and provided interesting data on the impact of these endophytic fungi on plant metabolism and physiology. Two flax cultivars (Bukoz and Nike) and two compositions of media for flax callus liquid cultures were tested. Biochemical analysis revealed enhanced levels of secondary metabolites (total flavonoid and total phenolic content) and photosynthetically active pigments in the flax callus cultures after treatment with the non-pathogenic fungal strain F. oxysporum Fo47 when compared to control, untreated cultures. In cultures with the selected, optimized conditions, FTIR analysis was performed and revealed changes in the structural properties of cell wall polymers after elicitation of cultures with F. oxysporum Fo47. The plant cell wall polymers were more strongly bound, and the crystallinity index (Icr) of cellulose was higher than in control, untreated samples. However, lignin and pectin levels were lower in the flax callus liquid cultures treated with the non-pathogenic strain of Fusarium when compared to the untreated control. The potential application of the non-pathogenic strain of F. oxysporum for enhancing the synthesis of desired secondary metabolites in plant tissue cultures is discussed.
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Lino , Fusarium , Fusarium/metabolismo , Lino/microbiología , Lino/metabolismo , Flavonoides/metabolismo , Fenoles/metabolismo , Pared Celular/metabolismo , Pared Celular/química , Semillas/microbiología , Semillas/metabolismoRESUMEN
The cell wall is an indispensable element of bacterial cells and a long-known target of many antibiotics. Penicillin, the first discovered beta-lactam antibiotic inhibiting the synthesis of cell walls, was successfully used to cure many bacterial infections. Unfortunately, pathogens eventually developed resistance to it. This started an arms race, and while novel beta-lactams, either natural or (semi)synthetic, were discovered, soon upon their application, bacteria were developing resistance. Currently, we are facing the threat of losing the race since more and more multidrug-resistant (MDR) pathogens are emerging. Therefore, there is an urgent need for developing novel approaches to combat MDR bacteria. The cell wall is a reasonable candidate for a target as it differentiates not only bacterial and human cells but also has a specific composition unique to various groups of bacteria. This ensures the safety and specificity of novel antibacterial agents that target this structure. Due to the shortage of low-molecular-weight candidates for novel antibiotics, attention was focused on peptides and proteins that possess antibacterial activity. Here, we describe proteinaceous agents of various origins that target bacterial cell wall, including bacteriocins and phage and bacterial lysins, as alternatives to classic antibiotic candidates for antimicrobial drugs. Moreover, advancements in protein chemistry and engineering currently allow for the production of stable, specific, and effective drugs. Finally, we introduce the concept of selective targeting of dangerous pathogens, exemplified by staphylococci, by agents specifically disrupting their cell walls.
Asunto(s)
Antibacterianos , Pared Celular , Bacterias Grampositivas , Pared Celular/efectos de los fármacos , Antibacterianos/farmacología , Antibacterianos/química , Bacterias Grampositivas/efectos de los fármacos , Humanos , Bacteriocinas/farmacología , Bacteriocinas/química , Infecciones por Bacterias Grampositivas/tratamiento farmacológico , Infecciones por Bacterias Grampositivas/microbiología , BacteriófagosRESUMEN
Dental caries (DC) is one of the most common oral diseases and is mainly caused by Streptococcus mutans (S. mutans). The use of antibiotics against S. mutans usually has side effects, including developing resistance. N-2-Hydroxypropyl trimethyl ammonium chloride chitosan (N-2-HACC), a natural product, has great potential utility in antibacterial agents owing to its low toxicity and good biocompatibility. Thus, the purpose of the present study was to explore the antimicrobial activity of N-2-HACC against S. mutans through the permeability of the cell wall, integrity of cell membrane, protein and nucleic acid synthesis, respiratory metabolism, and biofilm formation. Our results confirmed that the MIC of N-2-HACC against S. mutans was 0.625 mg/mL with a 90.01 ± 1.54% inhibition rate. SEM observed the formation of cavities on the surface of S. mutans after 12 h N-2-HACC treatment. The level of alkaline phosphatase (AKP) activity was higher in the N-2-HACC treatment group than in the control group, indicating that N-2-HACC can improve the permeability of the cell wall. Also, N-2-HACC treatment can destroy the cell membrane of S. mutans by increasing conductivity and absorbance at 260 nm, decreasing cell metabolic activity, and enhancing the fluorescence at 488 nm. Respiratory metabolism revealed that the activities of the Na+-K+-ATP enzyme, pyruvate kinase (PK), succinate dehydrogenase (SDH), and malate dehydrogenase (MDH) were decreased after N-2-HACC treatment, revealing that N-2-HACC can inhibit glycolysis and the tricarboxylic acid cycle (TCA cycle) of S. mutans. Moreover, N-2-HACC can also decrease the contents of the nucleic acid and solution protein of S. mutans, interfere with biofilm formation, and decrease the mRNA expression level of biofilm formation-related genes. Therefore, these results verify that N-2-HACC has strong antibacterial activity against S. mutans, acting via cell membrane integrity damage, increasing the permeability of cell walls, interfering with bacterial protein and nucleic acid synthesis, perturbing glycolysis and the TCA cycle, and inhibiting biofilm formation. It is suggested that N-2-HACC may represent a new potential synthetically modified antibacterial material against S. mutans.
Asunto(s)
Antibacterianos , Biopelículas , Quitosano , Pruebas de Sensibilidad Microbiana , Streptococcus mutans , Streptococcus mutans/efectos de los fármacos , Quitosano/química , Quitosano/farmacología , Quitosano/análogos & derivados , Antibacterianos/farmacología , Antibacterianos/química , Antibacterianos/síntesis química , Biopelículas/efectos de los fármacos , Proteínas Bacterianas/metabolismo , Proteínas Bacterianas/antagonistas & inhibidores , Caries Dental/microbiología , Caries Dental/tratamiento farmacológico , Pared Celular/efectos de los fármacos , Compuestos de Amonio Cuaternario/farmacología , Compuestos de Amonio Cuaternario/química , Compuestos de Amonio Cuaternario/síntesis químicaRESUMEN
Malassezia is a lipophilic commensal yeast that resides mainly on the mammalian skin and is also found to associate with the internal organs. Dysbiosis of Malassezia is related to several diseases and often escapes detection as it is difficult to culture and maintain. Malassezia cell wall differs from other budding yeasts like S. cerevisiae due to the difference in the lipid content and is difficult to transform. In this study, we present a methodology to stain Malassezia's nucleus and perform cell cycle studies. However, staining presents a challenge due to its exceptionally thick cell wall with high lipid content, hindering conventional methods. Our novel methodology addresses this challenge and enables the staining of the Malassezia nucleus with a low background. This would allow researchers to visualize the overall nuclear health specifically nuclear morphology and analyze DNA content, crucial for cell cycle progression. By employing DNA-specific dyes like DAPI or Hoechst, we can observe the nuclear structure, and using PI we can differentiate cells in distinct cell cycle phases using techniques like flow cytometry. This novel staining methodology unlocks the door for in-depth cell cycle analysis in Malassezia which has challenged us through ages being refractory to genetic manipulations, paving the way for a deeper understanding of this commensal fungus and its potential role in human health.
Asunto(s)
Ciclo Celular , Núcleo Celular , Malassezia , Coloración y Etiquetado , Núcleo Celular/metabolismo , Humanos , Coloración y Etiquetado/métodos , Citometría de Flujo/métodos , Pared Celular/metabolismoRESUMEN
Silica cell-wall formation in diatoms is a showcase for the ability of organisms to control inorganic mineralization. The process of silicification by these unicellular algae is tightly regulated within a membrane-bound organelle, the silica deposition vesicle (SDV). Two opposing scenarios were proposed to explain the tight regulation of this intracellular process: a template-mediated process that relies on preformed scaffolds, or a template-independent self-assembly process. The present work points to a third scenario, where the SDV membrane is a dynamic mold that shapes the forming silica. We use in-cell cryo-electron tomography to visualize the silicification process in situ, in its native-state, and with a nanometer-scale resolution. This reveals that the plasma membrane interacts with the SDV membrane via physical tethering at membrane contact sites, where the curvature of the tethered side of the SDV membrane mirrors the intricate silica topography. We propose that silica growth and morphogenesis result from the biophysical properties of the SDV and plasma membranes.