Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 35
Filtrar
Más filtros










Base de datos
Intervalo de año de publicación
1.
Environ Sci Pollut Res Int ; 31(24): 35133-35148, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38720127

RESUMEN

As a powerful engine for economic reform and curbing carbon emissions, digital inclusive finance provides solid support for achieving the goal of digital carbon neutrality. This study reveals the positive effect of digital inclusive finance on carbon emission reduction and the deeper reasons behind it by digging deeper into the panel data of 213 cities in China. The study adopts advanced empirical analysis methods to rigorously test the association between digital inclusive finance and carbon emissions. The results show that there is a strong positive correlation between the booming development of digital inclusive finance and the significant decline in carbon emissions. This finding remains solid after several rounds of robustness tests, which fully proves the reliability of the research results. Further mechanism analysis reveals the multiple paths of digital financial inclusion on carbon emission reduction. First, it promotes the optimization and upgrading of industrial structure by optimizing the allocation of financial resources, thus reducing the proportion of high-carbon emission industries. Second, digital inclusive finance attracts more foreign capital inflows and introduces advanced low-carbon technologies and management experience, further promoting the development of low-carbon economy. In addition, the study also found that the differences between different cities in terms of geographic location and city size have a significant impact on the carbon emission reduction effect of digital inclusive finance. In particular, the carbon emission reduction effect of digital inclusive finance is particularly significant in western regions, central cities, and first-tier cities. In response to these findings, this paper proposes a series of targeted policy recommendations. First, the financial service system should be further optimized to increase the coverage and penetration of digital inclusive finance, especially in less developed regions and small- and medium-sized cities. Second, regional policy synergies should be strengthened to form a strong synergy to promote the development of a low-carbon economy. In addition, it should guide capital flows to low-carbon industries and encourage enterprises to increase green technology research and development and application, while actively promoting low-carbon consumption concepts and guiding consumers to form green consumption habits. Through the implementation of these measures, it is expected that the potential of digital inclusive finance in the development of a low-carbon economy will be further stimulated, making a greater contribution to the realization of the goals of carbon peaking and carbon neutrality.


Asunto(s)
Carbono , China , Ciudades
2.
Cell Rep ; 43(4): 113973, 2024 Apr 23.
Artículo en Inglés | MEDLINE | ID: mdl-38507406

RESUMEN

We identified and validated a collection of circular RNAs (circRNAs) in Drosophila melanogaster. We show that depletion of the pro-viral circRNA circATP8B(2), but not its linear siblings, compromises viral infection both in cultured Drosophila cells and in vivo. In addition, circATP8B(2) is enriched in the fly gut, and gut-specific depletion of circATP8B(2) attenuates viral replication in an oral infection model. Furthermore, circATP8B(2) depletion results in increased levels of reactive oxygen species (ROS) and enhanced expression of dual oxidase (Duox), which produces ROS. Genetic and pharmacological manipulations of circATP8B(2)-depleted flies that reduce ROS levels rescue the viral replication defects elicited by circATP8B(2) depletion. Mechanistically, circATP8B(2) associates with Duox, and circATP8B(2)-Duox interaction is crucial for circATP8B(2)-mediated modulation of Duox activity. In addition, Gαq, a G protein subunit required for optimal Duox activity, acts downstream of circATP8B(2). We conclude that circATP8B(2) regulates antiviral defense by modulating Duox expression and Duox-dependent ROS production.


Asunto(s)
Proteínas de Drosophila , Drosophila melanogaster , ARN Circular , Especies Reactivas de Oxígeno , Animales , Especies Reactivas de Oxígeno/metabolismo , ARN Circular/genética , ARN Circular/metabolismo , Drosophila melanogaster/inmunología , Drosophila melanogaster/genética , Drosophila melanogaster/metabolismo , Proteínas de Drosophila/metabolismo , Proteínas de Drosophila/genética , Replicación Viral , ARN/metabolismo , ARN/genética , NADPH Oxidasas/metabolismo , NADPH Oxidasas/genética , Oxidasas Duales/metabolismo , Oxidasas Duales/genética
3.
Chem Commun (Camb) ; 60(17): 2401-2404, 2024 Feb 22.
Artículo en Inglés | MEDLINE | ID: mdl-38323599

RESUMEN

Herein, we report a new synthetic route to 1,4-epoxy-2-aryltetrahydro-1-benzazepine derivatives with high efficiency, namely the Rh(III)-catalyzed C-H allylation of nitrones with allyl precursors, followed by subsequent intramolecular 1,3-dipolar cycloaddition, to deliver the title compounds. This reaction is regio- and stereo-selective, generating the cis-isomer with a broad substrate scope and good functional group tolerance.

4.
J Ethnopharmacol ; 303: 115918, 2023 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-36436715

RESUMEN

ETHNOPHARMACOLOGICAL RELEVANCE: Fu Rong Ye (FRY), the leaf of Hibiscus mutabilis L., is a Chinese medicinal herb used to treat coughs and respiratory diseases. FRY is the major herbal component of the patent medicine Fupo Ganmao Granules for treating common cold. However, its anti-influenza active components and mechanism were not identified. AIM: Here, we aim to a) isolate the anti-influenza phytochemicals from FRY extract and b) explore its anti-flu mechanism. MATERIAL AND METHODS: Bioassay guided isolation was performed to get anti-influenza virus components. Influenza virus infected cells and mouse model were employed for efficacy evaluation. RESULTS: Using bioassay-guided isolation, the flavonoid tiliroside was obtained, which inhibited four IAV strains in MDCK cells with EC50 ranging from 3.87 to 27.61 µM by suppressing the viral ribonucleoprotein activity. Tiliroside also significantly downregulated the expression of cytokines/chemokines in A549 cells, and protected 50% of PR8-infected BALB/c mice from death and at 800 mg/kg/day, improved lung edema conditions. CONCLUSION: Tiliroside is effective for influenza virus infection treatment and promising for further drug development. This study is the first to demonstrate that tiliroside in FRY acts against influenza virus.


Asunto(s)
Hibiscus , Gripe Humana , Animales , Perros , Ratones , Humanos , Antivirales/farmacología , Antivirales/uso terapéutico , Gripe Humana/tratamiento farmacológico , Flavonoides , Células de Riñón Canino Madin Darby
5.
PLoS Genet ; 18(10): e1010429, 2022 10.
Artículo en Inglés | MEDLINE | ID: mdl-36301822

RESUMEN

Circular RNAs (circRNAs) are widely expressed in eukaryotes. However, only a subset has been functionally characterized. We identify and validate a collection of circRNAs in Drosophila, and show that depletion of the brain-enriched circRNA Edis (circ_Ect4) causes hyperactivation of antibacterial innate immunity both in cultured cells and in vivo. Notably, Edis depleted flies display heightened resistance to bacterial infection and enhanced pathogen clearance. Conversely, ectopic Edis expression blocks innate immunity signaling. In addition, inactivation of Edis in vivo leads to impaired locomotor activity and shortened lifespan. Remarkably, these phenotypes can be recapitulated with neuron-specific depletion of Edis, accompanied by defective neurodevelopment. Furthermore, inactivation of Relish suppresses the innate immunity hyperactivation phenotype in the fly brain. Moreover, we provide evidence that Edis encodes a functional protein that associates with and compromises the processing and activation of the immune transcription factor Relish. Importantly, restoring Edis expression or ectopic expression of Edis-encoded protein suppresses both innate immunity and neurodevelopment phenotypes elicited by Edis depletion. Thus, our study establishes Edis as a key regulator of neurodevelopment and innate immunity.


Asunto(s)
Inmunidad Innata , ARN Circular , Animales , ARN Circular/genética , Inmunidad Innata/genética , Factores de Transcripción/genética , Drosophila/genética , Drosophila/metabolismo , Transducción de Señal , ARN/genética
6.
PLoS Genet ; 18(10): e1010433, 2022 10.
Artículo en Inglés | MEDLINE | ID: mdl-36301831

RESUMEN

Circular RNAs (circRNAs) are a new group of noncoding/regulatory RNAs that are particularly abundant in the nervous system, however, their physiological functions are underexplored. Here we report that the brain-enriched circular RNA Edis (Ect4-derived immune suppressor) plays an essential role in neuronal development in Drosophila. We show that depletion of Edis in vivo causes defects in axonal projection patterns of mushroom body (MB) neurons in the brain, as well as impaired locomotor activity and shortened lifespan of adult flies. In addition, we find that the castor gene, which encodes a transcription factor involved in neurodevelopment, is upregulated in Edis knockdown neurons. Notably, castor overexpression phenocopies Edis knockdown, and reducing castor levels suppresses the neurodevelopmental phenotypes in Edis-depleted neurons. Furthermore, chromatin immunoprecipitation analysis reveals that the transcription factor Relish, which plays a key role in regulating innate immunity signaling, occupies a pair of sites at the castor promoter, and that both sites are required for optimal castor gene activation by either immune challenge or Edis depletion. Lastly, Relish mutation and/or depletion can rescue both the castor gene hyperactivation phenotype and neuronal defects in Edis knockdown animals. We conclude that the circular RNA Edis acts through Relish and castor to regulate neuronal development.


Asunto(s)
Proteínas de Drosophila , Drosophila , Animales , Drosophila/genética , ARN Circular/genética , Proteínas de Drosophila/genética , Factores de Transcripción/genética , Cuerpos Pedunculados , Drosophila melanogaster/fisiología
7.
Front Plant Sci ; 13: 968418, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36035708

RESUMEN

Cucumber is an important vegetable in China, and its yield and cultivation area are among the largest in the world. Excessive temperatures lead to high-temperature disorder in cucumber. Heat shock protein 20 (HSP20), an essential protein in the process of plant growth and development, is a universal protective protein with stress resistance. HSP20 plays crucial roles in plants under stress. In this study, we characterized the HSP20 gene family in cucumber by studying chromosome location, gene duplication, phylogenetic relationships, gene structure, conserved motifs, protein-protein interaction (PPI) network, and cis-regulatory elements. A total of 30 CsHSP20 genes were identified, distributed across 6 chromosomes, and classified into 11 distinct subgroups based on conserved motif composition, gene structure analyses, and phylogenetic relationships. According to the synteny analysis, cucumber had a closer relationship with Arabidopsis and soybean than with rice and maize. Collinearity analysis revealed that gene duplication, including tandem and segmental duplication, occurred as a result of positive selection and purifying selection. Promoter analysis showed that the putative promoters of CsHSP20 genes contained growth, stress, and hormone cis-elements, which were combined with protein-protein interaction networks to reveal their potential function mechanism. We further analyzed the gene expression of CsHSP20 genes under high stress and found that the majority of the CsHSP20 genes were upregulated, suggesting that these genes played a positive role in the heat stress-mediated pathway at the seedling stage. These results provide comprehensive information on the CsHSP20 gene family in cucumber and lay a solid foundation for elucidating the biological functions of CsHSP20. This study also provides valuable information on the regulation mechanism of the CsHSP20 gene family in the high-temperature resistance of cucumber.

8.
BMC Plant Biol ; 22(1): 164, 2022 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-35365089

RESUMEN

BACKGROUND: Proliferating cell nuclear antigen (PCNA) is one of the key factors for the DNA replication process and DNA damage repair. Most proteins interacting with PCNA have a common binding motif: PCNA interacting protein box (PIP box). However, some proteins with non-canonical PIP-box have also been reported to be the key factors that interacted with PCNA. RESULTS: Here we discovered the C terminal of a chromatin-remodeling factor CHR721 with non-canonical PIP-box was essential for interacting with OsPCNA in rice. Both OsPCNA and CHR721 were localized in the nuclei and function in response to DNA damages. CONCLUSIONS: Based on the results and previous work, we proposed a working model that CHR721 with non-canonical PIP-box interacted with OsPCNA and both of them probably participate in the DNA damage repair process.


Asunto(s)
Oryza , Cromatina , Daño del ADN , Reparación del ADN , Oryza/genética , Factores de Transcripción
9.
Fungal Genet Biol ; 159: 103664, 2022 04.
Artículo en Inglés | MEDLINE | ID: mdl-35026387

RESUMEN

The diploid fungal pathogen Candida albicans has three configurations at the mating type locus (MTL): heterozygous (a/α) and homozygous (a/a or α/α). C. albicans MTL locus encodes four transcriptional regulators (MTLa1, a2, α1, and α2). The conserved a1/α2 heterodimer controls not only mating competency but also white-opaque heritable phenotypic switching. However, the regulatory roles of MTLa2 and α1 are more complex and remain to be investigated. MTLa/a cells often express a cell type-specific genes and mate as the a-type partner, whereas MTLα/α cells express α-specific genes and mate as the α-type partner. In this study, we report that the MTLa2 regulator controls the formation of mating projections through both the a- and α-pheromone-sensing pathways and thus results in the bi-mater feature of "α cells" of C. albicans. Ectopic expression of MTLa2 in opaque α cells activates the expression of not only MFA1 and STE3 (a-pheromone receptor) but also MFα1 and STE2 (α-pheromone receptor). Inactivation of either the MFa-Ste3 or MFα-Ste2 pheromone-sensing pathway cannot block the MTLa2-induced development of mating projections. However, the case is different in MTLα1-ectopically expressed opaque a cells. Inactivation of the MFα-Ste2 but not the MFa-Ste3 pheromone-sensing pathway blocks MTLα1-induced development of mating projections. Therefore, MTLa2 and MTLα1 exhibit distinct regulatory features that control the mating response in C. albicans. These findings shed new light on the regulatory mechanism of bi-mating behaviors and sexual reproduction in C. albicans.


Asunto(s)
Candida albicans , Genes del Tipo Sexual de los Hongos , Candida albicans/metabolismo , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Regulación Fúngica de la Expresión Génica/genética , Genes del Tipo Sexual de los Hongos/genética , Feromonas/genética , Receptores de Feromonas/genética , Receptores de Feromonas/metabolismo , Reproducción
10.
J Hazard Mater ; 425: 127964, 2022 03 05.
Artículo en Inglés | MEDLINE | ID: mdl-34891015

RESUMEN

Programmed cell death (PCD) induced by aluminum (Al) is considered an important reason of Al phytotoxicity. However, the underlying mechanism of how Al induces PCD remains largely unknown in plants. The roles of glucose-6-phosphate dehydrogenase (G6PDH) and abscisic acid (ABA) in regulating Al-induced PCD were investigated in soybean roots. Al treatment increased G6PDH activity, while inhibition of G6PDH activity alleviated PCD occurrence and reactive oxygen species (ROS) accumulation under Al stress. Overexpression of cytosolic G6PDH1 enhanced G6PDH activity, thus promoting ROS production and cell death under Al exposure. Inhibition of NADPH oxidase activity mitigated ROS generation and cell death under Al stress. Further investigation demonstrated that G6PDH positively regulated the activity of NADPH oxidase under Al treatment using pharmacological and transgenic approach. Furthermore, Al stress increased ABA production, while inhibition of ABA biosynthesis alleviated PCD occurrence and ROS accumulation under Al stress. Interestingly, ABA upregulated G6PDH1 expression and G6PDH activity under Al stress. These results suggest that G6PDH mediates Al-induced PCD occurrence through the activation of NADPH oxidase-dependent ROS production, and ABA acts upstream of G6PDH in this process. This study will provide novel clues for the improvement of Al phytotoxicity in acidic soils.


Asunto(s)
Ácido Abscísico , Aluminio , Ácido Abscísico/toxicidad , Aluminio/toxicidad , Apoptosis , Glucosafosfato Deshidrogenasa/genética , Meristema , Raíces de Plantas , Especies Reactivas de Oxígeno , Glycine max/genética
11.
Int J Mol Sci ; 22(12)2021 Jun 18.
Artículo en Inglés | MEDLINE | ID: mdl-34207256

RESUMEN

ATP-binding cassette (ABC) transporter proteins are a gene super-family in plants and play vital roles in growth, development, and response to abiotic and biotic stresses. The ABC transporters have been identified in crop plants such as rice and buckwheat, but little is known about them in soybean. Soybean is an important oil crop and is one of the five major crops in the world. In this study, 255 ABC genes that putatively encode ABC transporters were identified from soybean through bioinformatics and then categorized into eight subfamilies, including 7 ABCAs, 52 ABCBs, 48 ABCCs, 5 ABCDs, 1 ABCEs, 10 ABCFs, 111 ABCGs, and 21 ABCIs. Their phylogenetic relationships, gene structure, and gene expression profiles were characterized. Segmental duplication was the main reason for the expansion of the GmABC genes. Ka/Ks analysis suggested that intense purifying selection was accompanied by the evolution of GmABC genes. The genome-wide collinearity of soybean with other species showed that GmABCs were relatively conserved and that collinear ABCs between species may have originated from the same ancestor. Gene expression analysis of GmABCs revealed the distinct expression pattern in different tissues and diverse developmental stages. The candidate genes GmABCB23, GmABCB25, GmABCB48, GmABCB52, GmABCI1, GmABCI5, and GmABCI13 were responsive to Al toxicity. This work on the GmABC gene family provides useful information for future studies on ABC transporters in soybean and potential targets for the cultivation of new germplasm resources of aluminum-tolerant soybean.


Asunto(s)
Transportadoras de Casetes de Unión a ATP/metabolismo , Aluminio/toxicidad , Glycine max/genética , Proteínas de Plantas/metabolismo , Transportadoras de Casetes de Unión a ATP/genética , Resistencia a Medicamentos/genética , Proteínas de Plantas/genética , Glycine max/efectos de los fármacos , Glycine max/metabolismo
12.
Plant Sci ; 310: 110988, 2021 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-34315602

RESUMEN

Alternative pathway (AP) plays essential roles in plant adaptation to environmental stress. However, the exact role of AP in response to aluminum (Al) toxicity remains elusive. We here provide solid evidences that the activated AP capacity in root tips of soybean alleviated Al toxicity. Furthermore, inhibition of AP by pharmacological or transgenic approach aggravated Al-induced programmed cell death (PCD) occurrence mediated through reactive oxygen species (ROS)-dependent mitochondrial pathway. Our results also demonstrated that nitric oxide (NO) plays a negative role in PCD occurrence caused by Al in soybean root tips. Interestingly, the alleviating effect of NO on Al-induced PCD could be blocked by AP inhibition. Further investigation showed that NO mediates the induction of AP resulting from the upregulation of AOX expression and pyruvate content in Al-treated root tips of soybean. Taken together, our results clearly suggest that AP participates in the alleviation of Al toxicity and also plays a critical role in the alleviating effect of NO on Al-induced PCD occurrence, which will open up new avenues for the improvement of plant growth in acidic soils.


Asunto(s)
Aluminio/toxicidad , Glycine max/metabolismo , Óxido Nítrico/metabolismo , Apoptosis/efectos de los fármacos , Proteínas de Plantas/efectos de los fármacos , Proteínas de Plantas/metabolismo , Raíces de Plantas/efectos de los fármacos , Raíces de Plantas/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Glycine max/efectos de los fármacos
13.
Plant Signal Behav ; 16(3): 1856546, 2021 03 04.
Artículo en Inglés | MEDLINE | ID: mdl-33315520

RESUMEN

The plasma membrane NADPH Oxidase-derived ROS as signaling molecules play crucial roles in salt stress response. As the motor organelle of cells, mitochondria are also important for salt tolerance. However, the possible interaction between NADPH Oxidase-derived ROS and mitochondria is not well studied. Here, a transgenic Arabidopsis expressing mitochondrial matrix-targeted pH-sensitive indicator cpYFP was used to monitor the pH dynamics in root cells under salt stress. A significant alkalization in mitochondria was observed when the root was exposed to NaCl or KCl, but not osmotic stress such as isotonic mannitol. Interestingly, when pretreated with the NADPH Oxidase inhibitor DPI, the mitochondrial alkalization in root cells was largely abolished. Genetic evidence further showed that salt-induced mitochondrial alkalization was significantly reduced in the loss of function mutant atrbohF . Pretreatment with endocytosis-related inhibitor PAO or TyrA23, which inhibited the ROS accumulation under salt treatment, almost abolished this effect. Furthermore, [Ca2+]cyt increase might also play important roles by affecting ROS generation to mediate salt-induced mitochondrial alkalization as indicated by treatment with plasma membrane Ca2+ channel inhibitor LaCl3 and mitochondrial Ca2+ uniporter inhibitor Ruthenium Red. Together, these results suggest that the plasma membrane NADPH Oxidase-derived ROS promote the mitochondrial alkalization under salt treatment, providing a possible link between different cellular compartments under salt stress.


Asunto(s)
Álcalis/metabolismo , Proteínas de Arabidopsis/metabolismo , Arabidopsis/fisiología , Mitocondrias/metabolismo , NADPH Oxidasas/metabolismo , Raíces de Plantas/citología , Especies Reactivas de Oxígeno/metabolismo , Estrés Salino/fisiología , Arabidopsis/citología , Arabidopsis/efectos de los fármacos , Proteínas de Arabidopsis/antagonistas & inhibidores , Calcio/metabolismo , Membrana Celular/efectos de los fármacos , Membrana Celular/metabolismo , Endocitosis/efectos de los fármacos , Inhibidores Enzimáticos/farmacología , Mitocondrias/efectos de los fármacos , NADPH Oxidasas/antagonistas & inhibidores , Compuestos Onio/farmacología , Estrés Salino/efectos de los fármacos , Cloruro de Sodio/farmacología
15.
Sheng Wu Gong Cheng Xue Bao ; 36(4): 707-715, 2020 Apr 25.
Artículo en Chino | MEDLINE | ID: mdl-32347065

RESUMEN

OsRhoGDI2 was isolated as a putative partner of Rho protein family member OsRacD from rice panicles by yeast two-hybrid, but its function remains unknown. In order to identify the function of OsRhoGDI2, OsRhoGDI2 knockout mutants were created by CRISPR/Cas9 technology. The results showed that two different homozygous mutants were obtained in T0 generation, and eight kinds homozygous mutants were identified in T1 generation. Sequence analysis revealed that the base substitution or base deletion occurred near the editing targets of the gene in knockout rice, and it could be expected that the truncated OsRhoGDI2 proteins lacking the RhoGDI conserved domain would be generated. Phenotype analysis showed that the OsRhoGDI2 knockout rice plants were significantly lower than the control plants. Statistical analysis confirmed that the significant decrease of plant height was due to the shortening of the second and third internodes, suggesting that OsRhoGDI2 gene may be related with rice height control.


Asunto(s)
Genes de Plantas , Oryza , Sistemas CRISPR-Cas , Genes de Plantas/genética , Oryza/genética , Oryza/crecimiento & desarrollo , Plantas Modificadas Genéticamente , Inhibidor beta de Disociación del Nucleótido Guanina rho/genética
16.
Emerg Microbes Infect ; 9(1): 413-426, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32079510

RESUMEN

Candida albicans is a major human fungal pathogen, capable of switching among a range of morphological types, such as the yeast form, including white and opaque cell types and the GUT (gastrointestinally induced transition) cell type, the filamentous form, including hyphal and pseudohyphal cell types, and chlamydospores. This ability is associated with its commensal and pathogenic life styles. In response to pheromone, C. albicans cells are able to form long mating projections resembling filaments. This filamentous morphology is required for efficient sexual mating. In the current study, we report the genetic regulatory mechanisms controlling the development of mating projections in C. albicans. Ectopic expression of MTLα1 in "a" cells induces the secretion of α-pheromone and promotes the development of mating projections. Using this inducible system, we reveal that members of the pheromone-sensing pathway (including the pheromone receptor), the Ste11-Hst7-Cek1/2 mediated MAPK signalling cascade, and the RAM pathway are essential for the development of mating projections. However, the cAMP/PKA signalling pathway and a number of key regulators of filamentous growth such as Hgc1, Efg1, Flo8, Tec1, Ume6, and Rfg1 are not required for mating projection formation. Therefore, despite the phenotypic similarities between filaments and mating projections in C. albicans, distinct mechanisms are involved in the regulation of these two morphologies.


Asunto(s)
Candida albicans/genética , Proteínas Fúngicas/genética , Genes del Tipo Sexual de los Hongos , Feromonas , Regulación Fúngica de la Expresión Génica , Hifa , Sistema de Señalización de MAP Quinasas
17.
Acta Biochim Biophys Sin (Shanghai) ; 51(5): 463-470, 2019 May 23.
Artículo en Inglés | MEDLINE | ID: mdl-30968937

RESUMEN

Filamentous development is associated with the ability to cause infections and colonize the host in pathogenic Candida species. Candida tropicalis is one of the major fungal pathogens of humans. The conserved transcriptional repressor Tup1 plays a critical role in the regulation of transcription and filamentation in yeast species. Despite its central role, the full coding sequence of TUP1 has not been found in the reported genome sequence of C. tropicalis to date. In this study, we report the identification of Tup1 and characterize its role in filamentous growth in C. tropicalis. As expected, C. tropicalis Tup1 exhibits general conserved features to the orthologs of other fungi in terms of its structure and function. Deletion of TUP1 in C. tropicalis leads to increased filamentation under several culture conditions. However, Tup1 indeed exhibits species-specific roles in the regulation of filamentous development in C. tropicalis. For example, unlike the tup1/tup1 mutant of Candida albicans, the tup1/tup1 mutant of C. tropicalis is able to exist in the yeast form at low temperatures or in the presence of N-acetylglucosamine (GlcNAc). Acidic pH conditions also favor the yeast form of the tup1/tup1 mutant of C. tropicalis. Quantitative real-time PCR (qRT-PCR) assays indicate that Tup1 may regulate filamentous development through the transcriptional control of key filamentation regulators in C. tropicalis, such as Ume6, Brg1, Wor1, Sfl2, Ahr1, and Zcf3. Taken together, our findings demonstrate both conserved and species-specific roles of Tup1 in the regulation of filamentation and provide novel insights into the biology of C. tropicalis.


Asunto(s)
Candida tropicalis/genética , Proteínas Fúngicas/genética , Regulación Fúngica de la Expresión Génica , Proteínas Represoras/genética , Acetilglucosamina/metabolismo , Candida albicans/genética , Candida albicans/metabolismo , Candida albicans/fisiología , Candida tropicalis/metabolismo , Candida tropicalis/fisiología , Candidiasis/microbiología , Proteínas Fúngicas/metabolismo , Humanos , Concentración de Iones de Hidrógeno , Mutación , Proteínas Represoras/metabolismo , Especificidad de la Especie , Temperatura
18.
Plant Cell Environ ; 42(8): 2340-2356, 2019 08.
Artículo en Inglés | MEDLINE | ID: mdl-30938457

RESUMEN

Hydrogen sulphide (H2 S) is emerging as an important signalling molecule involved in plant resistance to various stresses. However, the underlying mechanism of H2 S in aluminium (Al) resistance and the crosstalk between H2 S and nitric oxide (NO) in Al stress signalling remain elusive. Citrate secretion is a wide-spread strategy for plants against Al toxicity. Here, two citrate transporter genes, GmMATE13 and GmMATE47, were identified and characterized in soybean. Functional analysis in Xenopus oocytes and transgenic Arabidopsis showed that GmMATE13 and GmMATE47 mediated citrate exudation and enhanced Al resistance. Al treatment triggered H2 S generation and citrate exudation in soybean roots. Pretreatment with an H2 S donor significantly elevated Al-induced citrate exudation, reduced Al accumulation in root tips, and alleviated Al-induced inhibition of root elongation, whereas application of an H2 S scavenger elicited the opposite effect. Furthermore, H2 S and NO mediated Al-induced GmMATE expression and plasma membrane (PM) H+ -ATPase activity and expression. Further investigation showed that NO induced H2 S production by regulating the key enzymes involved in biosynthesis and degradation of H2 S. These findings indicate that H2 S acts downstream of NO in mediating Al-induced citrate secretion through the upregulation of PM H+ -ATPase-coupled citrate transporter cotransport systems, thereby conferring plant resistance to Al toxicity.


Asunto(s)
Aluminio/metabolismo , Proteínas Portadoras/metabolismo , Glycine max/metabolismo , Sulfuro de Hidrógeno/metabolismo , Óxido Nítrico/metabolismo , Proteínas de Plantas/metabolismo , Contaminantes del Suelo/metabolismo , Arabidopsis/genética , Arabidopsis/crecimiento & desarrollo , Arabidopsis/metabolismo , Raíces de Plantas/crecimiento & desarrollo , Raíces de Plantas/metabolismo , Glycine max/crecimiento & desarrollo , Estrés Fisiológico
19.
PLoS Biol ; 17(3): e2006966, 2019 03.
Artículo en Inglés | MEDLINE | ID: mdl-30865631

RESUMEN

While sexual reproduction is pervasive in eukaryotic cells, the strategies employed by fungal species to achieve and complete sexual cycles is highly diverse and complex. Many fungi, including Saccharomyces cerevisiae and Schizosaccharomyces pombe, are homothallic (able to mate with their own mitotic descendants) because of homothallic switching (HO) endonuclease-mediated mating-type switching. Under laboratory conditions, the human fungal pathogen Candida albicans can undergo both heterothallic and homothallic (opposite- and same-sex) mating. However, both mating modes require the presence of cells with two opposite mating types (MTLa/a and α/α) in close proximity. Given the predominant clonal feature of this yeast in the human host, both opposite- and same-sex mating would be rare in nature. In this study, we report that glucose starvation and oxidative stress, common environmental stresses encountered by the pathogen, induce the development of mating projections and efficiently permit same-sex mating in C. albicans with an "a" mating type (MTLa/a). This induction bypasses the requirement for the presence of cells with an opposite mating type and allows efficient sexual mating between cells derived from a single progenitor. Glucose starvation causes an increase in intracellular oxidative species, overwhelming the Heat Shock transcription Factor 1 (Hsf1)- and Heat shock protein (Hsp)90-mediated stress-response pathway. We further demonstrate that Candida TransActivating protein 4 (Cta4) and Cell Wall Transcription factor 1 (Cwt1), downstream effectors of the Hsf1-Hsp90 pathway, regulate same-sex mating in C. albicans through the transcriptional control of the master regulator of a-type mating, MTLa2, and the pheromone precursor-encoding gene Mating α factor precursor (MFα). Our results suggest that mating could occur much more frequently in nature than was originally appreciated and that same-sex mating could be an important mode of sexual reproduction in C. albicans.


Asunto(s)
Candida albicans/metabolismo , Candida albicans/fisiología , Proteínas Fúngicas/metabolismo , Proteínas HSP90 de Choque Térmico/metabolismo , Factores de Transcripción del Choque Térmico/metabolismo , Proteínas Fúngicas/genética , Regulación Fúngica de la Expresión Génica , Genes del Tipo Sexual de los Hongos/genética , Genes del Tipo Sexual de los Hongos/fisiología , Proteínas HSP90 de Choque Térmico/genética , Factores de Transcripción del Choque Térmico/genética , Transducción de Señal/genética , Transducción de Señal/fisiología
20.
Food Sci Biotechnol ; 27(4): 1085-1092, 2018 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-30263838

RESUMEN

Baizhi (Angelica dahurica) has been widely used as a traditional Chinese herbal medicine, functional food and cosmetic product ingredient, mostly because of the high furanocoumarin compounds in roots. Because the fresh root is perishable, drying techniques are needed to maintain a higher-quality product. Freeze-drying is the best method but energy-consuming and costly. The aim of this study was to analyze the quality (antioxidant and furanocoumarin content) of Baizhi roots after freeze-drying (the control) and in-the-shade, 40 and 70 °C drying. Antioxidant activity was revealed by 2,2-diphenyl-1-picrylhydrazyl and Fe2+ chelating assay, and the content of six furanocoumarin compounds, including xanthotoxin, bergapten, oxypeucedanin, imperatorin, phellopterin and isoimperatorin, was analyzed by liquid chromatography. Antioxidant activity was greater in roots with in-the-shade, 40 and 70 °C drying than freeze-drying. The furanocoumarin content pattern was similar with 70 °C drying and freeze-drying. A. dahurica roots dried at 70 °C may be an alternative method for maintaining high quality.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...