Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 42
Filtrar
Más filtros










Base de datos
Intervalo de año de publicación
1.
Int J Biol Macromol ; 256(Pt 2): 128233, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-38040166

RESUMEN

In this work, we report an environmentally friendly renewable nanocomposite magnetic lignin-based palladium nanoparticles (Fe3O4-lignin@Pd-NPs) for efficient wastewater treatment by decorating palladium nanoparticles without using any toxic reducing agents on the magnetic lignin abstracted from Poplar. The structure of composite Fe3O4-lignin@Pd-NPs was unambiguously confirmed by XRD, SEM, TEM, EDS, FTIR, and Zeta potential. After systematic evaluation of the use and efficiency of the composite to remove toxic organic dyes in wastewater, some promising results were observed as follows: Fe3O4-lignin@Pd-NPs exhibits highly active and efficient performance in the removal of toxic methylene blue (MB) (up to 99.8 %) wastewater in 2 min at different concentrations of MB and different pH values. Moreover, except for toxic MB, the other organic dyes including Rhodamine B (RhB), Rhodamine 6G (Rh6G), and Methyl Orange (MO) can also be removed efficiently by the composite. Finally, the easily recovered composite Fe3O4-lignin@Pd-NPs exhibits well stability and reusability, and catalytic efficiency is maintained well after ten cycles. In conclusion, the lignin-based magnetism Pd composite exhibits powerful potential practical application in industrial wastewater treatment.


Asunto(s)
Nanopartículas del Metal , Nanocompuestos , Purificación del Agua , Lignina , Nanopartículas del Metal/química , Paladio/química , Aguas Residuales , Colorantes
2.
J Hazard Mater ; 456: 131689, 2023 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-37245372

RESUMEN

In this study, Fe2O3 nanoparticles (Fe2O3 NPs) and CaO NPs were loaded on the zeolite sphere carrier to create nano Fe-Ca bimetallic oxide (Fe-Ca-NBMO) modified substrate, which was introduced into constructed wetland (CW) to remove Cu(II) and Ni(II) via constructing "substrate-microorganism" system. Adsorption experiments showed that the equilibrium adsorption capacities of Fe-Ca-NBMO modified substrate for Cu(II) and Ni(II) were respectively 706.48 and 410.59 mg/kg at an initial concentration of 20 mg/L, 2.45 and 2.39 times of gravel. The Cu(II) and Ni(II) removal efficiencies in CW with Fe-Ca-NBMO modified substrate respectively reached 99.7% and 99.9% at an influent concentration of 100 mg/L, significantly higher than those in gravel-based CW (47.0% and 34.3%). Fe-Ca-NBMO modified substrate could promote Cu(II) and Ni(II) removal by increasing electrostatic adsorption, chemical precipitation, as well as the abundances of resistant microorganisms (Geobacter, Desulfuromonas, Zoogloea, Dechloromonas, and Desulfobacter) and functional genes (copA, cusABC, ABC.CD.P, gshB, and exbB). This study provided an effective method to enhance Cu(II) and Ni(II) removal of electroplating wastewater by CW with Fe-Ca-NBMO modified substrate.

3.
J Int Med Res ; 51(1): 3000605221148410, 2023 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-36624979

RESUMEN

POEMS syndrome is a rare, serious, multisystem disorder and its diagnosis is frequently missed due to its varied clinical presentation. We report here, a 69-year-old woman with initial complaints of distended abdomen, who was misdiagnosed with tuberculosis but failed anti-tuberculosis treatment. Further examinations showed peripheral neuropathy, monoclonal plasma cell disease, sclerotic bone lesions, an elevated serum vascular endothelial growth factor (VEGF) concentration, lymph node hyperplasia, endocrine abnormalities, and skin hyperpigmentation. A diagnosis of POEMS syndrome was made and the patient responded to lenalidomide-based chemotherapy.


Asunto(s)
Síndrome POEMS , Humanos , Anciano , Síndrome POEMS/complicaciones , Síndrome POEMS/diagnóstico , Síndrome POEMS/patología , Factor A de Crecimiento Endotelial Vascular , Diagnóstico Diferencial , Abdomen/diagnóstico por imagen , Abdomen/patología
4.
Nucleic Acids Res ; 51(2): 619-630, 2023 01 25.
Artículo en Inglés | MEDLINE | ID: mdl-36546827

RESUMEN

Jasmonic acid (JA) signaling plays a pivotal role in plant development and defense. MYC2 is a master transcription factor in JA signaling, and was found to be phosphorylated and negatively regulated by MAP kinase and receptor-like kinase. However, the kinases that positively regulate MYC2 through phosphorylation and promote MYC2-mediated activation of JA response have not been identified. Here, we identified CK2 as a kinase that phosphorylates MYC2 and thus regulates the JA signaling. CK2 holoenzyme can interact with MYC2 using its regulatory subunits and phosphorylate MYC2 at multiple sites with its catalytic subunits. Inhibition of CK2 activity in a dominant-negative plant line, CK2mut, repressed JA response. On the other hand, increasing CK2 activity by overexpression of CKB4, a regulatory subunit gene of CK2, enhanced JA response in a MYC2-dependent manner. Substitution of the Ser and Thr residues at phosphorylation sites of MYC2 by CK2 with Ala impaired MYC2 function in activating JA response. Further investigations evidenced that CK2 facilitated the JA-induced increase of MYC2 binding to the promoters of JA-responsive genes in vivo. Our study demonstrated that CK2 plays a positive role in JA signaling, and reveals a previously undiscovered mechanism that regulates MYC2 function.


Asunto(s)
Proteínas de Arabidopsis , Arabidopsis , Factores de Transcripción Básicos con Cremalleras de Leucinas y Motivos Hélice-Asa-Hélice , Quinasa de la Caseína II , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Factores de Transcripción Básicos con Cremalleras de Leucinas y Motivos Hélice-Asa-Hélice/genética , Factores de Transcripción Básicos con Cremalleras de Leucinas y Motivos Hélice-Asa-Hélice/metabolismo , Ciclopentanos/metabolismo , Regulación de la Expresión Génica de las Plantas , Fosfotransferasas/genética , Quinasa de la Caseína II/metabolismo
5.
Org Lett ; 24(45): 8283-8288, 2022 11 18.
Artículo en Inglés | MEDLINE | ID: mdl-36331137

RESUMEN

In this work, we successfully explored an unexpected dehydrogenation triggered by Pd/Cu-catalyzed C(sp3)-H arylation and intramolecular C-N coupling of amides to synthesize the bioactive 1,2-dihydroquinoline scaffold with good regioselectivity and good compatibility of functional groups. This strategy provides an alternative route to realize molecular complexity and diversity from simple and readily available molecules via multiple C-H bond activation. Preliminary mechanistic studies demonstrated that ß,γ-dehydrogenation is triggered by the arylation of the C(sp3)-H bond and the intramolecular C-N coupling.


Asunto(s)
Amidas , Paladio , Amidas/química , Paladio/química , Catálisis , Estructura Molecular
6.
Artículo en Inglés | MEDLINE | ID: mdl-36231283

RESUMEN

The entrepreneurship of college students is an important issue related to the harmony and sustainable development of society as a whole. At present, the existing research in the industry pays less attention to the influence mechanism of non-cognitive ability and social support perception on college students' entrepreneurial intention. Using 450 survey data, this paper examines the relationship between non-cognitive ability and college students' entrepreneurial intention in terms of five dimensions: openness, conscientiousness, extraversion, agreeableness, and emotional stability. At the same time, it focuses on the role of social environmental factors, namely, social support perception in the relationship between the non-cognitive ability and entrepreneurial intention, and explores the influence path. The results show that openness, conscientiousness, extroversion, and emotional stability have significant positive effects on entrepreneurial intention; agreeableness has no significant effect on entrepreneurial intention; openness, conscientiousness, extraversion, agreeableness, and emotional stability have significant positive effects on social support perception. The mediating effect of social support perception is as follows-it is part of the intermediary effect between openness, conscientiousness, extraversion, and emotional stability on entrepreneurial intention; within the influence of agreeableness on entrepreneurial intention, it plays a complete intermediary role. This paper enriches the research results on the impact of non-cognitive ability on entrepreneurial intention, reveals the intermediary effect of social support perception on the impact of non-cognitive ability on college students' entrepreneurial intention, and broadens the field of vision for the study of college students' entrepreneurial intention. The research results can provide a decision-making reference for the promotion of the entrepreneurial intention of college students, alleviating the employment pressure of college graduates in China and promoting sustainable economic development.


Asunto(s)
Intención , Estudiantes , Emprendimiento , Humanos , Percepción Social , Apoyo Social , Estudiantes/psicología
7.
Int J Mol Sci ; 23(18)2022 Sep 14.
Artículo en Inglés | MEDLINE | ID: mdl-36142587

RESUMEN

Cynomorium songaricum is a perennial parasitic herb, and its stem is widely used as a traditional Chinese medicine, which largely relies on bioactive compounds (e.g., polysaccharides, flavonoids, and triterpenes). To date, although the optimum harvest time of stems has been demonstrated at the unearthed stage (namely the early flowering stage, EFS), the accumulation mechanism of polysaccharides and flavonoids during growth stages is still limited. In this study, the physiological characteristics (stem fresh weight, contents of soluble sugar and flavonoids, and antioxidant capacity) at four different growth stages (germination stage (GS), vegetative growth stage (VGS), EFS, and flowering stage (FS)) were determined, transcriptomics were analyzed by illumina sequencing, and expression levels of key genes were validated by qRT-PCR at the GS, VGS, and EFS. The results show that the stem biomass, soluble sugar and total flavonoids contents, and antioxidant capacity peaked at EFS compared with GS, VGS, and FS. A total of 6098 and 13,023 differentially expressed genes (DEGs) were observed at VGS and EFS vs. GS, respectively, with 367 genes co-expressed. Based on their biological functions, 109 genes were directly involved in polysaccharide and flavonoid biosynthesis as well as growth and development. The expression levels of key genes involved in polysaccharides (e.g., GLCs, XTHs and PMEs), flavonoids (e.g., 4CLLs, CYPs and UGTs), growth and development (e.g., AC58, TCPs and AP1), hormones biosynthesis and signaling (e.g., YUC8, AIPT and ACO1), and transcription factors (e.g., MYBs, bHLHs and WRKYs) were in accordance with changes of physiological characteristics. The combinational analysis of metabolites with transcriptomics provides insight into the mechanism of polysaccharide and flavonoid biosynthesis in C. songaricum during growth stages.


Asunto(s)
Cynomorium , Triterpenos , Antioxidantes/metabolismo , Cynomorium/genética , Cynomorium/metabolismo , Flavonoides , Hormonas , Polisacáridos , Azúcares , Factores de Transcripción , Transcriptoma
8.
Rice (N Y) ; 15(1): 1, 2022 Jan 04.
Artículo en Inglés | MEDLINE | ID: mdl-34982277

RESUMEN

BACKGROUND: The rice Waxy (Wx) gene plays a major role in seed amylose synthesis and consequently controls grain amylose content. Wx gene expression is highly regulated at the post-transcriptional level. In particular, the GT/TT polymorphism at the 5'splicing site of its 1st intron greatly affects this intron's splicing efficiency and defines two predominant Wx alleles, Wxa and Wxb. Wxa rice often harbours intermediate to high amylose contents, whereas Wxb rice exhibits low to intermediate amylose contents. By deleting the Wx 1st intron using CRISPR/Cas9 technology, we generate a completely novel Wx allele and further investigate how intron removal affects Wx gene expression and rice grain amylose content. RESULTS: CRISPR/Cas9-mediated targeted deletion of the Wx 1st intron was performed on 4 rice inbred lines: KY131 (Wxb), X32 (Wxb), X35 (Wxa) and X55 (Wxlv). Deletion of the 1st intron occurred in 8.6-11.8% of the primary transformants of these 4 inbred lines. Compared to wild-type plants, amylose content was significantly increased from 13.0% to approximately 24.0% in KY131 and X32 mutant lines, which both carried the Wxb allele. However, no significant difference in amylose content was observed between wild-type plants and X35 and X55 mutant lines, which carried the Wxa and Wxlv alleles, respectively. Wx gene expression analysis of wild-type plants and mutants yielded results that were highly consistent with amylose content results. KY131 and X32 mutants accumulated increased levels of steady mRNA transcripts compared with wild-type plants, whereas steady mRNA levels were not altered in X35 and X55 mutants compared with wild-type plants. Grain quality, including appearance quality and eating and cooking quality, which are tightly associated with amylose content, was also assessed in wild-type and mutant plants, and data were presented and analysed. CONCLUSIONS: This study presents a novel and rapid strategy to increase amylose content in inbred rice carrying a Wxb allele. Our data strongly suggest that the 1st intron of the Wx gene regulates Wx gene expression mainly at the post-transcriptional level in rice. This finding is in contrast to a previous hypothesis suggesting that it influences Wx gene transcription. In addition, removal of the first intron generates a completely novel Wx allele. Further studies on this new Wx allele will provide invaluable insights into the regulation of Wx gene expression, which will help researchers engineer new Wx alleles to facilitate the breeding of rice cultivars with better eating and cooking quality.

9.
Plant Cell Rep ; 41(4): 833-852, 2022 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-34773487

RESUMEN

The 14-3-3 proteins widely exist in almost all plant species. They specifically recognize and interact with phosphorylated target proteins, including protein kinases, phosphatases, transcription factors and functional proteins, offering an array of opportunities for 14-3-3s to participate in the signal transduction processes. 14-3-3s are multigene families and can form homo- and heterodimers, which confer functional specificity of 14-3-3 proteins. They are widely involved in regulating biochemical and cellular processes and plant growth and development, including cell elongation and division, seed germination, vegetative and reproductive growth, and seed dormancy. They mediate plant response to environmental stresses such as salt, alkaline, osmotic, drought, cold and other abiotic stresses, partially via hormone-related signalling pathways. Although many studies have reviewed the function of 14-3-3 proteins, recent research on plant 14-3-3s has achieved significant advances. Here, we provide a comprehensive overview of the fundamental properties of 14-3-3 proteins and systematically summarize and dissect the emerging advances in understanding the roles of 14-3-3s in plant growth and development and abiotic stress responses. Some ambiguous questions about the roles of 14-3-3s under environmental stresses are reviewed. Interesting questions related to plant 14-3-3 functions that remain to be elucidated are also discussed.


Asunto(s)
Proteínas 14-3-3 , Estrés Fisiológico , Proteínas 14-3-3/genética , Proteínas 14-3-3/metabolismo , Sequías , Regulación de la Expresión Génica de las Plantas , Desarrollo de la Planta , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas/genética , Plantas/metabolismo
10.
Molecules ; 26(23)2021 Dec 03.
Artículo en Inglés | MEDLINE | ID: mdl-34885931

RESUMEN

G-quadruplexes can bind with hemin to form peroxidase-like DNAzymes that are widely used in the design of biosensors. However, the catalytic activity of G-quadruplex/hemin DNAzyme is relatively low compared with natural peroxidase, which hampers its sensitivity and, thus, its application in the detection of nucleic acids. In this study, we developed a high-sensitivity biosensor targeting norovirus nucleic acids through rationally introducing a dimeric G-quadruplex structure into the DNAzyme. In this strategy, two separate molecular beacons each having a G-quadruplex-forming sequence embedded in the stem structure are brought together through hybridization with a target DNA strand, and thus forms a three-way junction architecture and allows a dimeric G-quadruplex to form, which, upon binding with hemin, has a synergistic enhancement of catalytic activities. This provides a high-sensitivity colorimetric readout by the catalyzing H2O2-mediated oxidation of 2,2'-azino-bis(3-ethylbenzothiazoline -6-sulfonic acid) diammonium salt (ABTS). Up to 10 nM of target DNA can be detected through colorimetric observation with the naked eye using our strategy. Hence, our approach provides a non-amplifying, non-labeling, simple-operating, cost-effective colorimetric biosensing method for target nucleic acids, such as norovirus-conserved sequence detection, and highlights the further implication of higher-order multimerized G-quadruplex structures in the design of high-sensitivity biosensors.


Asunto(s)
Técnicas Biosensibles/instrumentación , ADN Catalítico/química , G-Cuádruplex , Hemina/química , Norovirus/aislamiento & purificación , Infecciones por Caliciviridae/virología , Colorimetría/instrumentación , Diseño de Equipo , Humanos
11.
Molecules ; 27(1)2021 Dec 22.
Artículo en Inglés | MEDLINE | ID: mdl-35011276

RESUMEN

Cynomorium songaricum is a root holoparasitic herb that is mainly hosted in the roots of Nitraria roborowskii and Nitraria sibirica distributed in the arid desert and saline-alkaline regions. The stem of C. songaricum is widely used as a traditional Chinese medicine and applied in anti-viral, anti-obesity and anti-diabetes, which largely rely on the bioactive components including: polysaccharides, flavonoids and triterpenes. Although the differences in growth characteristics of C. songaricum between N. roborowskii and N. sibirica have been reported, the difference of the two hosts on growth and polysaccharides biosynthesis in C. songaricum as well as regulation mechanism are not limited. Here, the physiological characteristics and transcriptome of C. songaricum host in N. roborowskii (CR) and N. sibirica (CS) were conducted. The results showed that the fresh weight, soluble sugar content and antioxidant capacity on a per stem basis exhibited a 3.3-, 3.0- and 2.1-fold increase in CR compared to CS. A total of 16,921 differentially expressed genes (DEGs) were observed in CR versus CS, with 2573 characterized genes, 1725 up-regulated and 848 down-regulated. Based on biological functions, 50 DEGs were associated with polysaccharides and starch metabolism as well as their transport. The expression levels of the selected 37 genes were validated by qRT-PCR and almost consistent with their Reads Per kb per Million values. These findings would provide useful references for improving the yield and quality of C. songaricum.


Asunto(s)
Cynomorium/fisiología , Polisacáridos/biosíntesis , Transcriptoma , Antioxidantes/metabolismo , Transporte Biológico , Metabolismo de los Hidratos de Carbono , Perfilación de la Expresión Génica , Almidón/metabolismo , Azúcares/metabolismo
12.
Org Lett ; 21(6): 1668-1671, 2019 03 15.
Artículo en Inglés | MEDLINE | ID: mdl-30801191

RESUMEN

In this letter, we successfully explored a cascade Pd/Cu-catalyzed intermolecular C(sp3)-H arylation of amides and intramolecular C-N coupling reaction. This method provides a one-pot strategy to synthesize 3,4-2 H-quinolinone with good regioselectivity of C-H arylation and C-N coupling from C-I and C-X bonds from readily available starting materials.

13.
Nat Prod Res ; 33(10): 1442-1448, 2019 May.
Artículo en Inglés | MEDLINE | ID: mdl-29281920

RESUMEN

Two new eremophilenolides, ligushicins A (1) and B (2), and two known compounds including ß-sitosterol and ursolic acid were isolated from Ligulariopsis shichuana. The structures of new compounds were established on the basis of 1D and 2D NMR data and HRESIMS data interpretation. The absolute configuration of new compounds was assigned by ECD spectroscopy, and that of ligushicins A (1) was confirmed by X-ray diffraction analysis. The antifungal and antifeedant activities of new compounds were evaluated against four plant pathogenic fungi and third-instar larvae of Plutella xylostella, respectively. Ligushicins A (1) and B (2) exhibited potent antifungal activity against Botrytis cinerea and Fusarium oxysporum with minimum inhibitory concentration (MIC) values ranging from 50 to 100 mg/L, while they also exhibited weak antifeedant activities.


Asunto(s)
Antifúngicos/farmacología , Asteraceae/química , Botrytis/efectos de los fármacos , Conducta Alimentaria/efectos de los fármacos , Fusarium/efectos de los fármacos , Raíces de Plantas/química , Triterpenos/aislamiento & purificación , Triterpenos/farmacología , Antifúngicos/química , Pruebas de Sensibilidad Microbiana , Análisis Espectral/métodos , Triterpenos/química
14.
Arch Pharm Res ; 41(12): 1162-1169, 2018 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-30378038

RESUMEN

Four new acylated triterpene glycosides with aliphatic chains (4-7) as well as five known triterpenoids were isolated from the flower buds of Staphylea bumalda with bioassay guidance. Their structures were determined on the basis of spectral techniques, including IR, 1D and 2D NMR, and HR-APCI-MS. Most compounds (except 8) were isolated from S. bumalda for the first time. Additionally, the neuroprotective effects of 1 and 4-9 on suckling rat primary cultured hippocampal neurons against H2O2-induced injury were evaluated in vitro. The four new triterpenoids (4-7) showed neuroprotective effects, which increased the cell viability to over 74% at different concentrations, which was higher than the negative control (59%), while compounds 1 and 8-9 exhibited cytotoxic activity.


Asunto(s)
Glicósidos/farmacología , Hipocampo/efectos de los fármacos , Peróxido de Hidrógeno/antagonistas & inhibidores , Neuronas/efectos de los fármacos , Fármacos Neuroprotectores/farmacología , Triterpenos/farmacología , Animales , Flores/química , Glicósidos/química , Glicósidos/aislamiento & purificación , Hipocampo/patología , Peróxido de Hidrógeno/farmacología , Magnoliopsida/química , Neuronas/patología , Fármacos Neuroprotectores/química , Fármacos Neuroprotectores/aislamiento & purificación , Ratas , Ratas Sprague-Dawley , Triterpenos/química , Triterpenos/aislamiento & purificación
15.
Nat Prod Res ; 32(13): 1518-1524, 2018 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-29022760

RESUMEN

A new germacrenolide (1) and fourteen known terpenoids (2-15) were isolated from the barks of Magnolia maudiae (Dunn) Figlar (Magnoliaceae). The structure of (7αH,11ßH)-2α,8α-dihydroxy-4α,5ß-epoxy-germacr-1(10)-en-6α,12-olide (1) was elucidated by physical and spectroscopic data analysis, including 1D, 2D NMR and HR-ESI-MS. Lyratol F (9) was isolated from Magnolia for the first time. The structures of known compounds were established by comparing their spectroscopic data with those in literatures.


Asunto(s)
Magnolia/química , Terpenos/química , Espectroscopía de Resonancia Magnética , Estructura Molecular , Corteza de la Planta/química , Espectrometría de Masa por Ionización de Electrospray
16.
Molecules ; 22(11)2017 Nov 17.
Artículo en Inglés | MEDLINE | ID: mdl-29149016

RESUMEN

Five new oleanane-type saponins, named ligushicosides A-E, and three known oleanane-type saponins were isolated from the roots of Ligulariopsis shichuana. Their structures were established by a combination of spectroscopic techniques, including 1D and 2D NMR and high resolution electrospray ionization mass spectroscopy (HR-ESI-MS). Furthermore, all isolates were evaluated for their yeast α-glucosidase inhibitory effects and exhibited potent inhibition against α-glucosidase, while compounds 1 and 2 showed excellent inhibitory activities. The 3-O-glycoside moiety in oleanane-type saponin is important for the α-glucosidase inhibitory effects.


Asunto(s)
Inhibidores de Glicósido Hidrolasas/química , Inhibidores de Glicósido Hidrolasas/farmacología , Extractos Vegetales/química , Extractos Vegetales/farmacología , Raíces de Plantas/química , Saponinas/química , Saponinas/farmacología , Activación Enzimática/efectos de los fármacos , Hidrólisis , Espectroscopía de Resonancia Magnética , Estructura Molecular , Relación Estructura-Actividad , alfa-Glucosidasas/química
17.
Plant Physiol Biochem ; 109: 240-247, 2016 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-27750098

RESUMEN

Protein kinase CK2, which consists of two α and two ß subunits, plays an essential role in plant development and is implicated in plant responses to abiotic stresses, including salt and heat. However, the function of CK2 in response to heavy metals such as cadmium (Cd) has not yet been established. In this study, the transgenic line CKB4ox, which overexpresses CKB4 encoding the CK2ß subunit and has elevated CK2 activity, was used to investigate the potential role of CK2 in response to Cd stress in Arabidopsis thaliana. Under Cd stress, CKB4ox showed reduced root growth and biomass accumulation as well as decreased chlorophyll and proline contents compared with wild type. Furthermore, increased Cd accumulation and a higher H2O2 content were found in CKB4ox, possibly contributing to the inhibition of CKB4ox growth under Cd stress. Additionally, altered levels of Cd and H2O2 were found to be associated with decreased expression of genes involved in Cd efflux, Cd sequestration and H2O2 scavenging. Taken together, these results suggest that elevated expression of CKB4 and increased CK2 activity enhance the sensitivity of plants to Cd stress by affecting Cd and H2O2 accumulation, including the modulation of genes involved in Cd transport and H2O2 scavenging. This study provides direct evidence for the involvement of plant CK2 in the response to Cd stress.


Asunto(s)
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Cadmio/farmacocinética , Cadmio/toxicidad , Quinasa de la Caseína II/metabolismo , Peróxido de Hidrógeno/metabolismo , Arabidopsis/genética , Arabidopsis/crecimiento & desarrollo , Proteínas de Arabidopsis/genética , Transporte Biológico Activo/genética , Quinasa de la Caseína II/genética , Clorofila/metabolismo , Regulación del Desarrollo de la Expresión Génica , Regulación Enzimológica de la Expresión Génica , Regulación de la Expresión Génica de las Plantas , Genes de Plantas , Plantas Modificadas Genéticamente , Prolina/metabolismo , Subunidades de Proteína , Estrés Fisiológico
18.
Guang Pu Xue Yu Guang Pu Fen Xi ; 36(3): 896-902, 2016 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-27400545

RESUMEN

Human telomeric G-quadruplex is a four-stranded structure folded by guanines (G) via Hoogsteen hydrogen bonding. The ligands which stabilize the G-quadruplex are often telomerase inhibitors and may become antitumor agents. Here, the interaction between a lignan derivative liliflorin A and human telomeric sequence dGGG (TTAGGG)3G-quadruplex HTG21 were examined by CD, FRET, and NMR spectroscopic methods. In addition, Molecular Docking was used to study the binding of liliflorin A to dTAGGG (TTAGGG)3 G-quadruplex HTG23. The CD data showed that liliflorin A enhanced HTG21 T(m). The T(m) value of G-quadruplex was enhanced 3.2 degrees C by 4.0 µmol x L(-1) liliflorin A in FRET. The NMR spectra of HTG21 showed vivid alteration after reacting with liliflorin A in 3 hours. Molecular Docking suggested liliflorin A bound to the wide groove of HTG23 at G9, G10, G16 and G17. Liliflorin A was the first lignan derivative that could stabilize HTG21 selectively and provided a new candidate for antitumor drug design targeting on human telomeric G-quadruplex.


Asunto(s)
G-Cuádruplex , Lignanos/química , Análisis Espectral , Telómero/química , Antineoplásicos , Inhibidores Enzimáticos , Guanina , Humanos , Enlace de Hidrógeno , Ligandos , Simulación del Acoplamiento Molecular
19.
Nat Prod Res ; 30(21): 2396-401, 2016 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-27210247

RESUMEN

A new sesquiterpene manghookerins A (1) was isolated from the barks of Manglietia hookeri (Magnoliaceae) together with five known eudesmane-type sesquiterpenes. The structure of manghookerins A (1) was elucidated by physical and spectroscopic data analysis, including 1D and 2D NMR, HR-ESI-MS and X-ray diffraction. The structures of known sesquiterpenes were established by comparing their spectroscopic data with those in literatures.


Asunto(s)
Magnoliaceae/química , Sesquiterpenos/aislamiento & purificación , Espectroscopía de Resonancia Magnética , Corteza de la Planta/química , Sesquiterpenos/química , Difracción de Rayos X
20.
Plant Cell Rep ; 35(5): 1071-80, 2016 May.
Artículo en Inglés | MEDLINE | ID: mdl-26883224

RESUMEN

KEY MESSAGE: Arabidopsis CK2 α4 subunit regulates the primary root and hypocotyl elongation, lateral root formation, cotyledon expansion, rosette leaf initiation and growth, flowering, and anthocyanin biosynthesis. Casein kinase 2 (CK2) is a conserved tetrameric kinase composed of two α and two ß subunits. The inhibition of CK2 activity usually results in severe developmental deficiency. Four genes (CKA1-CKA4) encode CK2 α subunit in Arabidopsis. Single mutations of CKA1, CKA2, and CKA3 do not affect the normal growth of Arabidopsis, while the cka1 cka2 cka3 triple mutants are defective in cotyledon and hypocotyl growth, lateral root development, and flowering. The inhibition of CKA4 expression in cka1 cka2 cka3 background further reduces the number of lateral roots and delays the flowering time. Here, we report the characterization of a novel knockout mutant of CKA4, which exhibits various developmental defects including reduced primary root and hypocotyl elongation, increased lateral root density, delayed cotyledon expansion, retarded rosette leaf initiation and growth, and late flowering. The examination of the cellular basis for abnormal root development of this mutant revealed reduced root meristem cells with enhanced RETINOBLASTOMA-RELATED (RBR) expression that promotes cell differentiation in root meristem. Moreover, this cka4-2 mutant accumulates higher anthocyanin in the aerial part and shows an increased expression of anthocyanin biosynthetic genes, suggesting a novel role of CK2 in modulating anthocyanin biosynthesis. In addition, the complementation test using primary root elongation assay as a sample confirms that the changed phenotypes of this cka4-2 mutant are due to the lack of CKA4. Taken together, this study reveals an essential role of CK2 α4 subunit in multiple developmental processes in Arabidopsis.


Asunto(s)
Antocianinas/metabolismo , Arabidopsis/enzimología , Quinasa de la Caseína II/metabolismo , Regulación de la Expresión Génica de las Plantas , Arabidopsis/citología , Arabidopsis/genética , Arabidopsis/crecimiento & desarrollo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Quinasa de la Caseína II/genética , Cotiledón/citología , Cotiledón/enzimología , Cotiledón/genética , Cotiledón/crecimiento & desarrollo , Flores/citología , Flores/enzimología , Flores/genética , Flores/crecimiento & desarrollo , Genes Reporteros , Hipocótilo/citología , Hipocótilo/enzimología , Hipocótilo/genética , Hipocótilo/crecimiento & desarrollo , Mutación , Fenotipo , Hojas de la Planta/citología , Hojas de la Planta/enzimología , Hojas de la Planta/genética , Hojas de la Planta/crecimiento & desarrollo , Raíces de Plantas/citología , Raíces de Plantas/enzimología , Raíces de Plantas/genética , Raíces de Plantas/crecimiento & desarrollo , Plantones/citología , Plantones/enzimología , Plantones/genética , Plantones/crecimiento & desarrollo , Alineación de Secuencia
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...