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1.
Plant Physiol Biochem ; 212: 108784, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38823093

RESUMO

TGA-binding (TGA) transcription factors, characterized by the basic region/leucine zipper motif (bZIP), have been recognized as pivotal regulators in plant growth, development, and stress responses through their binding to the as-1 element. In this study, the TGA gene families in melon, watermelon, cucumber, pumpkin, and zucchini were comprehensively characterized, encompassing analyses of gene/protein structures, phylogenetic relationships, gene duplication events, and cis-acting elements in gene promoters. Upon transient expression in Nicotiana benthamiana, the melon CmTGAs, with typical bZIP and DOG1 domains, were observed to localize within the nucleus. Biochemical investigation revealed specific interactions between CmTGA2/3/5/8/9 and CmNPR3 or CmNPR4. The CmTGA genes exhibited differential expression patterns in melon plants in response to different hormones like salicylic acid, methyl jasmonate, and ethylene, as well as a fungal pathogen, Stagonosporopsis cucurbitacearum that causes gummy stem blight in melon. The overexpression of CmTGA3, CmTGA8, and CmTGA9 in Arabidopsis plants resulted in the upregulation of AtPR1 and AtPR5 expression, thereby imparting enhanced resistance to Pseudomonas syringae pv. Tomato DC3000. In contrast, the overexpression of CmTGA7 or CmTGA9 resulted in a compromised resistance to Botrytis cinerea, coinciding with a concomitant reduction in the expression levels of AtPDF1.2 and AtMYC2 following infection with B. cinerea. These findings shed light on the important roles of specific CmTGA genes in plant immunity, suggesting that genetic manipulation of these genes could be a promising avenue for enhancing plant immune responses.


Assuntos
Arabidopsis , Cucurbitaceae , Resistência à Doença , Regulação da Expressão Gênica de Plantas , Doenças das Plantas , Proteínas de Plantas , Arabidopsis/genética , Arabidopsis/microbiologia , Resistência à Doença/genética , Doenças das Plantas/microbiologia , Doenças das Plantas/genética , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Cucurbitaceae/genética , Cucurbitaceae/microbiologia , Plantas Geneticamente Modificadas , Família Multigênica , Filogenia , Expressão Ectópica do Gene , Genoma de Planta , Fatores de Transcrição de Zíper de Leucina Básica/genética , Fatores de Transcrição de Zíper de Leucina Básica/metabolismo
2.
Plants (Basel) ; 13(9)2024 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-38732457

RESUMO

Increasing the ultraviolet radiation (UV) level, particularly UV-B due to damage to the stratospheric ozone layer by human activities, has huge negative effects on plant and animal metabolism. As a widely grown cool-season forage grass and turfgrass in the world, perennial ryegrass (Lolium perenne) is UV-B-sensitive. To study the effects of miR164, a highly conserved microRNA in plants, on perennial ryegrass under UV stress, both OsmiR164a overexpression (OE164) and target mimicry (MIM164) transgenic perennial ryegrass plants were generated using agrobacterium-mediated transformation, and UV-B treatment (~600 µw cm-2) of 7 days was imposed. Morphological and physiological analysis showed that the miR164 gene affected perennial ryegrass UV tolerance negatively, demonstrated by the more scorching leaves, higher leaf electrolyte leakage, and lower relative water content in OE164 than the WT and MIM164 plants after UV stress. The increased UV sensitivity could be partially due to the reduction in antioxidative capacity and the accumulation of anthocyanins. This study indicated the potential of targeting miR164 and/or its targeted genes for the genetic manipulation of UV responses in forage grasses/turfgrasses; further research to reveal the molecular mechanism underlying how miR164 affects plant UV responses is needed.

3.
Plants (Basel) ; 12(23)2023 Nov 26.
Artigo em Inglês | MEDLINE | ID: mdl-38068612

RESUMO

Whole-genome duplication is a significant evolutionary mechanism in plants, with polyploid plants often displaying larger organs and enhanced adaptability to unfavorable conditions compared to their diploid counterparts. The cell wall acts as a primary defense for plant cells against external stresses, playing an essential role in the plant's resistance to various stressors. In this study, we utilized both autotetraploid and its donor diploid rice (Oryza sativa L.) to analyze their phenotypic differences comparatively, the composition of key cell wall components, and the expression of related genes under normal conditions, as well as under stress from Magnaporthe oryzae (M. oryzae) and salt. Our findings indicated that autotetraploid rice exhibits significantly larger phenotypic characteristics under normal conditions than diploid rice. At the seedling stage, the lignin, cellulose, hemicellulose, and pectin levels in autotetraploid rice were markedly lower than in diploid rice. Additionally, 24 genes associated with major cell wall components showed differential expression between diploid and tetraploid rice. At the filling stage, the lignin and pectin content in autotetraploid rice were significantly higher than in diploid rice, while the levels of cellulose and hemicellulose were notably lower. Under M. oryzae stress or salt stress, autotetraploid rice showed smaller lesion areas and less wilting than diploid rice. The increased lignin content in autotetraploid rice under M. oryzae stress suggested a stronger adaptive capacity to adverse conditions. Compared to salt stress, M. oryzae stress induced more differential expression of genes related to major cell wall components. In this study, we explored the differences in the major cell wall components of diploid and homologous tetraploid rice under various treatment conditions. This study provides valuable insights into understanding the cell wall's adaptive mechanisms in autotetraploid rice when facing blast disease and salt stress, and it reveals the differential gene expression linked to these adaptive capabilities.

4.
Biosens Bioelectron ; 238: 115552, 2023 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-37542978

RESUMO

Exosomal surface proteins are potentially useful for breast cancer diagnosis and awareness of risk. However, some detection techniques involving complex operations and expensive instrumentation are limited to advance to clinical applications. To solve this problem, we develop a dual-modal sensor combining naked-eye detection and electrochemical assay of exosomal surface proteins from breast cancer. Most of existing sensors rely on aptamers recognizing exosomes and generating amplified signals at the same time, which require well-designed aptamer probes to avoid difficulties in identifying exosomes. In our work, aptamers not bound by the exosomes can serve as complete templates to induce formation of G quadruplexes. The peroxidase activity of the G-quadruplex/hemin DNAzyme catalyze substrates can generate both color and electrochemical signals. The developed dual-modal sensor offers a remarkable capability to differentiate nonmetastatic, metastatic breast cancer patients, and healthy individuals through the analysis of exosomal surface proteins. The sensor's distinctive features, including its universality, simplicity, and cost-effectiveness, position it as a promising diagnostic tool in breast cancer research and clinical practice.


Assuntos
Técnicas Biossensoriais , Neoplasias da Mama , Colorimetria , Técnicas Eletroquímicas , Humanos , Linhagem Celular , Neoplasias da Mama/diagnóstico por imagem , Técnicas Biossensoriais/instrumentação , Técnicas Biossensoriais/métodos , Colorimetria/instrumentação , Colorimetria/métodos , DNA Catalítico/química , DNA Catalítico/metabolismo , Técnicas Eletroquímicas/instrumentação , Técnicas Eletroquímicas/métodos , Exossomos/química , Exossomos/metabolismo , Quadruplex G
5.
Mol Plant Pathol ; 24(11): 1414-1429, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37452482

RESUMO

Rice false smut, caused by the ascomycete fungus Ustilaginoidea virens, which infects rice florets before heading, severely threatens rice grain yield and quality worldwide. The U. virens genome encodes a number of glycoside hydrolase (GH) proteins. So far, the functions of these GHs in U. virens are largely unknown. In this study, we identified a GH42 protein secreted by U. virens, named UvGHF1, that exhibits ß-galactosidase activity. UvGHF1 not only functions as an essential virulence factor during U. virens infection, but also serves as a pathogen-associated molecular pattern (PAMP) in Nicotiana benthamiana and rice. The PAMP activity of UvGHF1 is independent of its ß-galactosidase activity. Moreover, UvGHF1 triggers cell death in N. benthamiana in a BAK1-dependent manner. Ectopic expression of UvGHF1 in rice induces pattern-triggered immunity and enhances rice resistance to fungal and bacterial diseases. RNA-seq analysis revealed that UvGHF1 expression in rice not only activates expression of many defence-related genes encoding leucine-rich repeat receptor-like kinases and WRKY and ERF transcription factors, but also induces diterpenoid biosynthesis and phenylpropanoid biosynthesis pathways. Therefore, UvGHF1 contributes to U. virens virulence, but is also recognized by the rice surveillance system to trigger plant immunity.


Assuntos
Oryza , Fatores de Virulência , Fatores de Virulência/genética , Glicosídeo Hidrolases/genética , Doenças das Plantas/microbiologia , Oryza/microbiologia , Imunidade Vegetal , beta-Galactosidase
6.
J Adv Res ; 2023 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-37385342

RESUMO

INTRODUCTION: Chemo- and bio-genic metallic nanoparticles (NPs), as a novel nano-enabled strategy, have demonstrated a great potential in crop health management. OBJECTIVE: The current study aimed to explore the efficacy of advanced nanocomposites (NCs), integrating biogenic (bio) metallic NPs and plant immunity-regulating hormones, in crop disease control. METHODS: Iron (Fe) NPs were biosynthesized using cell-free supernatant of a Fe-resistant strains, Bacillus marisflavi ZJ-4. Further, salicylic acid-coated bio-FeNPs (SI) NCs were prepared via co-precipitation method under alkaline conditions. Both bio-FeNPs and SINCs were characterized using basic analytical techniques, including Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction analysis, and scanning/transmission electron microscopy. RESULTS: Bio-FeNPs and SINCs had variable shapes with average sizes of 72.35 nm and 65.87 nm, respectively. Under greenhouse conditions, bio-FeNPs and SINCs improved the agronomic traits of the watermelon plants, and SINCs outperformed bio-FeNPs, providing the maximum growth promotion of 32.5%. Soil-drenching with bio-FeNPs and SINCs suppressed Fusarium oxysporum f. sp. niveum-caused Fusarium wilt in watermelon, and SINCs provided better protection than bio-FeNPs, through inhibiting the fungal invasive growth within host plants. SINCs improved the antioxidative capacity and primed a systemic acquired resistance (SAR) response via activating the salicylic acid signaling pathway genes. These findings indicate that SINCs can reduce the severity of Fusarium wilt in watermelon by modulating antioxidative capacity and potentiating SAR to restrict in planta fungal invasive growth. CONCLUSION: This study provides new insights into the potential of bio-FeNPs and SINCs as biostimulants and bioprotectants for growth promotion and Fusarium wilt suppression, ensuring sustainable watermelon production.

7.
Anal Chem ; 95(2): 1549-1555, 2023 01 17.
Artigo em Inglês | MEDLINE | ID: mdl-36598887

RESUMO

Long non-coding RNAs (lncRNAs) played vital roles in physiological and pathological conditions. Consistent results from cell experiments, animal experiments, and clinical studies suggested that lncRNA HULC was an oncogenic lncRNA serving as a potential diagnostic and prognostic marker of hepatocellular carcinoma. In this study, we developed a fluorescent biosensor for lncRNA HULC detection based on rolling circle amplification (RCA) induced by multi-primer probes. Multiple primer probes can not only combine with lncRNA to break its secondary structure, which was conducive to lncRNA captured by Y-shaped probes, but also trigger multiple RCA reactions to achieve signal amplification and the goal of sensitive detection of lncRNA. Compared to previous detection methods, in this scheme, we took advantage of the long sequence characteristics of lncRNA to make it a carrier that can bind multiple primers to initiate RCA. This newly designed biosensor provided a linear range from 1 pM to 100 nM with a detection limit of 0.06 pM. This method can provide a new idea for the application of isothermal amplification in detecting lncRNA. Furthermore, the application of the biosensor in liver cancer cell lines and whole blood samples from hepatocellular carcinomatosis patients also confirmed that the method had good selectivity and sensitivity to lncRNA HULC. This method offered a new way for transforming specific lncRNA into clinical application for diagnosis, prognosis, or predicting treatment response.


Assuntos
Técnicas Biossensoriais , Carcinoma Hepatocelular , Neoplasias Hepáticas , RNA Longo não Codificante , Animais , Carcinoma Hepatocelular/diagnóstico , Carcinoma Hepatocelular/genética , RNA Longo não Codificante/genética , Neoplasias Hepáticas/diagnóstico , Neoplasias Hepáticas/genética , Detecção Precoce de Câncer , Primers do DNA/metabolismo , Técnicas Biossensoriais/métodos , Técnicas de Amplificação de Ácido Nucleico/métodos , Limite de Detecção
8.
Anal Chem ; 95(7): 3606-3612, 2023 02 21.
Artigo em Inglês | MEDLINE | ID: mdl-36565296

RESUMO

Exosome-based liquid biopsy technologies play an increasingly prominent role in tumor diagnosis. However, the simple and sensitive method for counting exosomes still faces considerable challenges. In this work, the CD63 aptamer-modified DNA tetrahedrons on the gold electrode were used as recognition elements for the specific capture of exosomes. Partially complementary DNA probes act as bridges linking trapped exosomes and three AuNP-DNA signal probes. This clover-like structure can tackle the recognition and sensitivity issues arising from the undesired AuNP aggregation event. When cancerous exosomes are present in the system, the high accumulation of methylene blue molecules from DNA-AuNP nanocomposites on the surface of the electrode leads to an intense current signal. According to the results, the aptasensor responds to MCF-7 cell-derived exosomes in the concentration range from 1.0 × 103 to 1.0 × 108 particles·µL-1, with the detection limit of 158 particles·µL-1. Furthermore, the aptasensor has been extended to serum samples from breast cancer patients and exhibited excellent specificity. To sum it up, the aptasensor is sensitive, straightforward, less expensive, and fully capable of receiving widespread application in clinics for tumor monitoring.


Assuntos
Aptâmeros de Nucleotídeos , Técnicas Biossensoriais , Neoplasias da Mama , Exossomos , Nanopartículas Metálicas , Humanos , Feminino , Exossomos/química , Ouro/química , Neoplasias da Mama/diagnóstico , DNA/análise , Células MCF-7 , Aptâmeros de Nucleotídeos/química , Técnicas Biossensoriais/métodos , Nanopartículas Metálicas/química
9.
Hortic Res ; 9: uhac140, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36072835

RESUMO

Isatis indigotica accumulates several active substances, including C-glycosylflavonoids, which have important pharmacological activities and health benefits. However, enzymes catalyzing the methylation step of C-glycosylflavonoids in I. indigotica remain unknown. In this study, three O-methyltransferases (OMTs) were identified from I. indigotica that have the capacity for O-methylation of the C-glycosylflavonoid isoorientin. The Type II OMTs IiOMT1 and IiOMT2 efficiently catalyze isoorientin to form isoscoparin, and decorate one of the aromatic vicinal hydroxyl groups on flavones and methylate the C6, C8, and 3'-hydroxyl positions to form oroxylin A, wogonin, and chrysoeriol, respectively. However, the Type I OMT IiOMT3 exhibited broader substrate promiscuity and methylated the C7 and 3'-hydroxyl positions of flavonoids. Further site-directed mutagenesis studies demonstrated that five amino acids of IiOMT1/IiOMT2 (D121/D100, D173/D149, A174/A150R, N200/N176, and D248/D233) were critical residues for their catalytic activity. Additionally, only transient overexpression of Type II OMTs IiOMT1 and IiOMT2 in Nicotiana benthamiana significantly increased isoscoparin accumulation, indicating that the Type II OMTs IiOMT1 and IiOMT2 could catalyze the methylation step of C-glycosylflavonoid, isoorientin at the 3'-hydroxyl position. This study provides insights into the biosynthesis of methylated C-glycosylflavonoids, and IiOMTs could be promising catalysts in the synthesis of bioactive compounds.

10.
New Phytol ; 236(4): 1422-1440, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36068953

RESUMO

Rice false smut caused by Ustilaginoidea virens is becoming one of the most recalcitrant rice diseases worldwide. However, the molecular mechanisms underlying rice immunity against U. virens remain unknown. Using genetic, biochemical and disease resistance assays, we demonstrated that the xb24 knockout lines generated in non-Xa21 rice background exhibit an enhanced susceptibility to the fungal pathogens U. virens and Magnaporthe oryzae. Consistently, flg22- and chitin-induced oxidative burst and expression of pathogenesis-related genes in the xb24 knockout lines were greatly attenuated. As a central mediator of energy signaling, SnRK1A interacts with and phosphorylates XB24 at Thr83 residue to promote ATPase activity. SnRK1A is activated by pathogen-associated molecular patterns and positively regulates plant immune responses and disease resistance. Furthermore, the virulence effector SCRE1 in U. virens targets host ATPase XB24. The interaction inhibits ATPase activity of XB24 by blocking ATP binding to XB24. Meanwhile, SCRE1 outcompetes SnRK1A for XB24 binding, and thereby suppresses SnRK1A-mediated phosphorylation and ATPase activity of XB24. Our results indicate that the conserved SnRK1A-XB24 module in multiple crop plants positively contributes to plant immunity and uncover an unidentified molecular strategy to promote infection in U. virens and a novel host target in fungal pathogenesis.


Assuntos
Oryza , Oryza/metabolismo , Adenosina Trifosfatases/metabolismo , Fosforilação , Doenças das Plantas/microbiologia , Resistência à Doença , Moléculas com Motivos Associados a Patógenos/metabolismo , Quitina/metabolismo , Trifosfato de Adenosina/metabolismo
11.
Anal Chem ; 94(34): 11767-11772, 2022 08 30.
Artigo em Inglês | MEDLINE | ID: mdl-35972912

RESUMO

Programmed-death ligand 1 (PD-L1), as one of major immune checkpoints, is highly expressed on cancer cells and participates in the immune escape process of tumor cells. The level of PD-L1 in patients is closely related to the efficacy of anti-PD-L1 immunotherapy, and patients with a high level have better response to immunotherapy. Therefore, PD-L1 can be an indicator of patient classification and medication guidance. In this work, we have developed a novel strategy for detecting PD-L1-positive circulating tumor cells based on steric hindrance generated after cell capture, using the primer exchange reaction (PER) amplification method. The principle is to modify a single strand containing the PD-L1 aptamer and the PER primer on the electrode surface. When PD-L1-positive circulating tumor cells exist, the aptamer will capture them. The steric hindrance generated by the captured cells due to their large volume hinders the subsequent approach of PER materials, thus hindering the occurrence of PER signal amplification. The number of HRP bound to the electrode surface is reduced, and the current signal output is inversely proportional to the number of captured cells. This method realizes convenient and sensitive detection of PD-L1-positive tumor cells and provides a new means for clinical judgment of whether patients should adopt immunotherapy.


Assuntos
Células Neoplásicas Circulantes , Receptor de Morte Celular Programada 1 , Antígeno B7-H1/metabolismo , Humanos , Fatores Imunológicos , Imunoterapia/métodos , Microambiente Tumoral
12.
Clin Exp Nephrol ; 26(6): 512-521, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35195816

RESUMO

OBJECTIVE: To explore the effect of RORA on LPS-induced renal epithelial cell apoptosis and the underlying mechanism. METHODS: LPS-treated HK-2 cells were established as a cellular model of acute kidney injury. The expression of RORA or/and PGC-1α in LPS-induced HK-2 cells was altered by transfection. qRT-PCR and Western blotting were used to detect the expression changes of RORA and PGC-1α. ELISA was performed to detect the expression of IL-1ß and IL-6 and the activity of caspase-3. Western blotting was applied for visualization of cleaved caspase-3. CCK-8 and flow cytometry were used to assess cell proliferation and apoptosis. Dual-luciferase reporter and ChIP-qPCR were utilized to verify the binding of RORA to PGC-1α promoter. RESULTS: LPS treatment decreased the expression of RORA and PGC-1α and increased that of cleaved caspase-3 in HK-2 cells. Also, LPS treatment inhibited HK-2 cell proliferation and promoted HK-2 cell apoptosis and secretion of IL-1ß and IL-6. Overexpression of RORA or PGC-1α eliminated the adverse effects of LPS treatment in HK-2 cells. RORA drove the transcription of PGC-1α by binding PGC-1α promoter. Knockdown of PGC-1α offset the reduction in HK-2 cell injury caused by overexpression of RORA. CONCLUSION: RORA reduces LPS-induced apoptosis of renal epithelial cells by promoting PGC-1α transcription.


Assuntos
Interleucina-6 , Lipopolissacarídeos , Apoptose , Caspase 3/metabolismo , Células Epiteliais/metabolismo , Humanos , Interleucina-6/genética , Lipopolissacarídeos/farmacologia , Membro 1 do Grupo F da Subfamília 1 de Receptores Nucleares/metabolismo , Membro 1 do Grupo F da Subfamília 1 de Receptores Nucleares/farmacologia
13.
Int J Mol Sci ; 23(2)2022 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-35054806

RESUMO

We previously showed that overexpression of the rice ERF transcription factor gene OsBIERF3 in tobacco increased resistance against different pathogens. Here, we report the function of OsBIERF3 in rice immunity and abiotic stress tolerance. Expression of OsBIERF3 was induced by Xanthomonas oryzae pv. oryzae, hormones (e.g., salicylic acid, methyl jasmonate, 1-aminocyclopropane-1-carboxylic acid, and abscisic acid), and abiotic stress (e.g., drought, salt and cold stress). OsBIERF3 has transcriptional activation activity that depends on its C-terminal region. The OsBIERF3-overexpressing (OsBIERF3-OE) plants exhibited increased resistance while OsBIERF3-suppressed (OsBIERF3-Ri) plants displayed decreased resistance to Magnaporthe oryzae and X. oryzae pv. oryzae. A set of genes including those for PRs and MAPK kinases were up-regulated in OsBIERF3-OE plants. Cell wall biosynthetic enzyme genes were up-regulated in OsBIERF3-OE plants but down-regulated in OsBIERF3-Ri plants; accordingly, cell walls became thicker in OsBIERF3-OE plants but thinner in OsBIERF3-Ri plants than WT plants. The OsBIERF3-OE plants attenuated while OsBIERF3-Ri plants enhanced cold tolerance, accompanied by altered expression of cold-responsive genes and proline accumulation. Exogenous abscisic acid and 1-aminocyclopropane-1-carboxylic acid, a precursor of ethylene biosynthesis, restored the attenuated cold tolerance in OsBIERF3-OE plants while exogenous AgNO3, an inhibitor of ethylene action, significantly suppressed the enhanced cold tolerance in OsBIERF3-Ri plants. These data demonstrate that OsBIERF3 positively contributes to immunity against M. oryzae and X. oryzae pv. oryzae but negatively regulates cold stress tolerance in rice.


Assuntos
Adaptação Fisiológica , Temperatura Baixa , Oryza/microbiologia , Oryza/fisiologia , Doenças das Plantas/microbiologia , Imunidade Vegetal , Proteínas de Plantas/metabolismo , Fatores de Transcrição/metabolismo , Ácido Abscísico/farmacologia , Bactérias/metabolismo , Parede Celular/efeitos dos fármacos , Parede Celular/metabolismo , Parede Celular/ultraestrutura , Resistência à Doença/imunologia , Secas , Etilenos/farmacologia , Fungos/fisiologia , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Magnaporthe/efeitos dos fármacos , Magnaporthe/fisiologia , Oryza/efeitos dos fármacos , Oryza/genética , Doenças das Plantas/genética , Doenças das Plantas/imunologia , Reguladores de Crescimento de Plantas/farmacologia , Proteínas de Plantas/genética , Plantas Geneticamente Modificadas , Tolerância ao Sal/efeitos dos fármacos , Tolerância ao Sal/genética , Estresse Fisiológico , Regulação para Cima/efeitos dos fármacos , Regulação para Cima/genética , Xanthomonas/efeitos dos fármacos , Xanthomonas/fisiologia
14.
Biosensors (Basel) ; 12(1)2022 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-35049663

RESUMO

As one of the pivotal signal molecules, hydrogen peroxide (H2O2) has been demonstrated to play important roles in many physiological processes of plants. Continuous monitoring of H2O2 in vivo could help understand its regulation mechanism more clearly. In this study, a disposable electrochemical microsensor for H2O2 was developed. This microsensor consists of three parts: low-cost stainless-steel wire with a diameter of 0.1 mm modified by gold nanoparticles (disposable working electrode), an untreated platinum wire with a diameter of 0.1 mm (counter electrode), and an Ag/AgCl wire with a diameter of 0.1 mm (reference electrode), respectively. The microsensor could detect H2O2 in levels from 10 to 1000 µM and exhibited excellent selectivity. On this basis, the dynamic change in H2O2 in the vein of tomato leaf under high salinity was continuously monitored in vivo. The results showed that the production of H2O2 could be induced by high salinity within two hours. This study suggests that the disposable electrochemical microsensor not only suits continuously detecting H2O2 in microscopic plant tissue in vivo but also reduces the damage to plants. Overall, our strategy will help to pave the foundation for further investigation of the generation, transportation, and elimination mechanism of H2O2 in plants.


Assuntos
Nanopartículas Metálicas , Solanum lycopersicum , Técnicas Eletroquímicas , Eletrodos , Ouro , Peróxido de Hidrogênio/química , Folhas de Planta , Aço Inoxidável
15.
Talanta ; 235: 122748, 2021 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-34517616

RESUMO

Cancer-derived exosomes have emerged as a valuable biomarker for cancer diagnosis and prognosis. However, the heterogeneity of exosomes often leads to low selectivity based on the single recognition method. Given this, we have developed a dual-aptamer recognition strategy based on G-quadruplex nanowires for selective analysis of exosomes. In this work, target exosomes were first captured by CD63 aptamers modified on magnetic beads (MBs) and then combined with AS1411 aptamer, which shows high binding affinity to nucleolin when forming stable G-quadruplex structure. Then the free myc monomer can spontaneously assemble into higher order G-wire superstructures on the allosteric AS1411, and resulting enhanced fluorescence signal, which can realize sensitive and specific analysis of the target exosomes. This dual-aptamer recognition-based method is simple and universal for different types of exosomes, which is of great significance for clinical cancer diagnosis.


Assuntos
Aptâmeros de Nucleotídeos , Exossomos , Quadruplex G , Nanofios , Neoplasias , Humanos
16.
Mikrochim Acta ; 188(6): 220, 2021 06 02.
Artigo em Inglês | MEDLINE | ID: mdl-34076759

RESUMO

Efficient capture and release of circulating tumor cells play an important role in cancer diagnosis, but the limited affinity of monovalent adhesion molecules in existing capture technologies leads to low capture efficiency, and the captured cells are difficult to be separated. Inspired by the phenomenon that the long tentacles of jellyfish contain multiple adhesion domains and can effectively capture moving food, we have constructed a biomimetic recognition strategy to capture and release tumor cells. In details, gold-coated magnetic nanomaterials (Au@Fe3O4 NPs) were first prepared and characterized by scanning electron microscopy, UV-vis absorption spectra, and Zeta potential. Then, the DNA primers modified on Au@Fe3O4 nanoparticles can be extended to form many radialized DNA products by rolling circle amplification. These long DNA products resemble jellyfish tentacles and contain multivalent aptamers that can be extended into three dimensions to increase the accessibility of target cells, resulting in efficient, simple, rapid, and specific cells capture. The capture efficiencies are no less than 92% in PBS buffer and 77% in blood. Subsequently, DNase I was selected to degrade biomimetic tentacles to release the captured tumor cells with high viability. This release strategy can not only improve cell viability, but also reduce a tedious release process and unnecessary costs. We believe that the proposed method can be expanded for the capture and release of various tumor cells and will inspire the development of circulating tumor cells analysis. A biomimetic recognition strategy for capture and release of circulating tumor cells has been developed. This method modified specific P1 DNA primers on Au@Fe3O4 NPs to form many radialized DNA products by rolling circle amplification. These products can efficiently capture CTCs since it contains multiple aptamers with a multivalent binding capacity. This make it a promising tool to capture and release of other tumor cells, and will inspire the development of CTC analysis.


Assuntos
Biomimética/métodos , Células Neoplásicas Circulantes/metabolismo , Aptâmeros de Nucleotídeos/química , Aptâmeros de Nucleotídeos/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Óxido Ferroso-Férrico/química , Ouro/química , Células HeLa , Humanos , Nanopartículas de Magnetita/química , Nanopartículas de Magnetita/toxicidade , Técnicas de Amplificação de Ácido Nucleico
17.
Toxicology ; 456: 152786, 2021 05 30.
Artigo em Inglês | MEDLINE | ID: mdl-33872729

RESUMO

Ustilaginoidins, a group of bis-naphtho-γ-pyrones, are one of the major mycotoxins produced by Ustilaginoidea virens. This group of bis-naphtho-γ-pyrone mycotoxins has been demonstrated to have antibacterial and immunological inhibitory activities and strong cytotoxicity to human oral epidermoid carcinoma. However, little is yet known about the toxicity of ustilaginoidins to animals or toxicity mechanisms. In this study, toxicity assays to zebrafish larvae show that ustilaginoidin D is highly toxic to zebrafish with an LC50 of ∼7.50 µM. Ustilaginoidin D causes an obvious yolk sac absorption delay and liver damage in zebrafish, which is indicated by liver atrophy and the increased alanine and aspartate transaminase activities. Interestingly, different doses of ustilaginoidin D can alter zebrafish movement behavior in a distinct manner. Transcriptome analyses show that global gene expression profiling in zebrafish is significantly changed in response to ustilaginoidin D exposure. KEGG pathway analyses reveal that differentially expressed genes are enriched in the pathways related to lipid metabolism and hyperbilirubinemia, which are indicators of severe liver injury. Consistently, the expression of the marker genes for hepatotoxic responses is significantly induced by ustilaginoidin D. The findings indicate that ustilaginoidin D induces lipid metabolism disorders and hepatotoxicity in zebrafish larvae and poses a potential risk to food safety.


Assuntos
Doença Hepática Induzida por Substâncias e Drogas/metabolismo , Hypocreales , Larva/efeitos dos fármacos , Larva/metabolismo , Locomoção/efeitos dos fármacos , Micotoxinas/toxicidade , Animais , Doença Hepática Induzida por Substâncias e Drogas/patologia , Relação Dose-Resposta a Droga , Metabolismo dos Lipídeos/efeitos dos fármacos , Metabolismo dos Lipídeos/fisiologia , Locomoção/fisiologia , Micotoxinas/isolamento & purificação , Peixe-Zebra
18.
Materials (Basel) ; 14(4)2021 Feb 04.
Artigo em Inglês | MEDLINE | ID: mdl-33557236

RESUMO

The hot deformation behaviors of the SJTU-1 alloy, the high-throughput scanned casting Nickel-based superalloy, was investigated by compression test in the temperature range of 900 to 1200 °C and strain rate range of 0.1-0.001 s-1. The hot processing map has been constructed with the instability zone. At the beginning of hot deformation, the flow stress moves rapidly to the peak value with the increased strain rates. Meanwhile, the peak stress is decreased with the increased temperature at the same strain rates. However, the peak stress shows the same tendency with the strain rates at the same temperature. The optimum hot deformation condition was determined in the temperature range of 1000-1075 °C, and the strain rate range of 0.005-0.1 s-1. The microstructure investigation indicates the strain rate significantly affects the characteristics of the microstructure. The deformation constitutive equation has also been discussed as well.

19.
Biosens Bioelectron ; 178: 113032, 2021 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-33513534

RESUMO

The competitive endogenous RNA hypothesis is a new mechanism of RNA dialogue, in which circRNA-miRNA interaction (cmRRI) is found to be widely involved in the regulation of gene expression in tumors and other diseases. It is urgent but challenging to develop a convenient and efficient method to study the interaction between target circRNA and the candidate miRNAs. In this work, a biosensing method that allows directly analyzing cmRRI has been developed, so as to reveal the RNA dialogue strategy. The sensing system uses a bifunctional magnetic bead for the capture of target circRNA/miRNA complex as well as the signal amplification. Based on the nature of circRNA as a miRNA sponge, only if the target circRNAs and its regulatory miRNAs coexist as a complex, can the rolling circle amplification reaction be initiated to give a fluorescent signal as the output. Compared with traditional methods where the circRNA and its regulatory miRNAs have been separately analyzed, our design allows the integrated profiling of specific cmRRI by correlation characterization of two correlative RNAs, which represents a function-oriented method. The presented method also shows the analysis of the potential binding affinity of candidate miRNAs to target circRNAs. Furthermore, we have verified the ability of the sensor to directly detect cmRRI in biological samples, which reveals the promising applicability of this method for biomedical and clinical researches in the future.


Assuntos
Técnicas Biossensoriais , MicroRNAs , Perfilação da Expressão Gênica , Redes Reguladoras de Genes , MicroRNAs/genética , RNA/genética , RNA Circular
20.
Theor Appl Genet ; 133(6): 1911-1926, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32157354

RESUMO

KEY MESSAGE: The bHLH transcription factor, PPLS1, interacts with SiMYB85 to control the color of pulvinus and leaf sheath by regulating anthocyanin biosynthesis in foxtail millet (Setaria italica). Foxtail millet (Setaria italica), a self-pollinated crop with numerous small florets, is difficult for cross-pollination. The color of pulvinus and leaf sheath with purple being dominant to green is an indicative character and often used for screening authentic hybrids in foxtail millet crossing. Deciphering molecular mechanism controlling this trait would greatly facilitate genetic improvement of cultivars in foxtail millet. Here, using the F2 bulk specific-locus amplified fragment sequencing approach, we mapped the putative causal gene for the purple color of pulvinus and leaf sheath (PPLS) trait to a 100 Kb region on chromosome 7. Expression analyses of the 15 genes in this region revealed that Seita.7G195400 (renamed here as PPLS1) was differentially expressed between purple and green cultivars. PPLS1 encodes a bHLH transcription factor and is localized in the nucleus with a transactivation activity. Furthermore, we observed that expression of a MYB transcription factor gene, SiMYB85 (Seita.4G086300) involved in anthocyanin biosynthesis, shows a totally positive association with that of PPLS1. Heterologous co-expression of both PPLS1 and SiMYB85 in tobacco leaves led to elevated anthocyanin accumulation and expression of some anthocyanin-related genes. Furthermore, PPLS1 physically interacts with SiMYB85. Taken together, our results suggest that PPLS1 interacts with SiMYB85 to control the color of pulvinus and leaf sheath by regulating anthocyanin biosynthesis in foxtail millet.


Assuntos
Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Proteínas de Plantas/genética , Pulvínulo/genética , Setaria (Planta)/genética , Fatores de Transcrição/genética , Antocianinas/química , Clorofila/química , Cor , Biologia Computacional , Regulação da Expressão Gênica de Plantas , Fenótipo , Filogenia , Polimorfismo de Nucleotídeo Único
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