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1.
Phys Chem Chem Phys ; 26(24): 17315-17323, 2024 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-38860395

RESUMO

Halide perovskites have distinguished themselves among the numerous optoelectronic materials due to their versatile processing technology and exceptional optical response. Unfortunately, their stability and toxicity from heavy metals severely hamper their development, in addition to the challenge of further improving photovoltaic performance. Hence, a lead-free perovskite-based heterojunction, C2N/CsGeI3, is investigated using a hybrid density functional, including electron structures, charge density differences, optical properties and more. The study reveals the presence of a built-in electric field directed from the CsGeI3 to the C2N layer. Moreover, based on the work function, it is confirmed that the electrons are transferred in a Z-scheme mechanism after the CsGeI3 contacts with the C2N layer. Under light irradiation, the construction of the C2N/CsGeI3 heterojunction significantly enhances optical absorption within the range of visible-light wavelengths. Additionally, the impact of interfacial strain on the C2N/CsGeI3 is explored and discussed. These findings not only suggest that the C2N/CsGeI3 heterojunction holds promise for photovoltaic applications but also provide a theoretical insight into lead-free perovskite-based functional materials.

2.
Molecules ; 29(12)2024 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-38930861

RESUMO

Hydrogen generation by photocatalytic water-splitting holds great promise for addressing the serious global energy and environmental crises, and has recently received significant attention from researchers. In this work, a method of assembling GeC/MXY (M = Zr, Hf; X, Y = S, Se) heterojunctions (HJs) by combining GeC and MXY monolayers (MLs) to construct direct Z-scheme photocatalytic systems is proposed. Based on first-principles calculations, we found that all the GeC/MXY HJs are stable van der Waals (vdW) HJs with indirect bandgaps. These HJs possess small bandgaps and exhibit strong light-absorption ability across a wide range. Furthermore, the built-in electric field (BIEF) around the heterointerface can accelerate photoinduced carrier separation. More interestingly, the suitable band edges of GeC/MXY HJs ensure sufficient kinetic potential to spontaneously accomplish water redox reactions under light irradiation. Overall, the strong light-harvesting ability, wide light-absorption range, small bandgaps, large heterointerfacial BIEFs, suitable band alignments, and carrier migration paths render GeC/MXY HJs highly efficient photocatalysts for overall water decomposition.

3.
Int J Mol Sci ; 24(19)2023 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-37833996

RESUMO

The extensive use of fossil fuels and global climate change have raised ever-increasing attention to sustainable development, global food security and the replacement of fossil fuels by renewable energy. Several C4 monocot grasses have excellent photosynthetic ability, stress tolerance and may rapidly produce biomass in marginal lands with low agronomic inputs, thus representing an important source of bioenergy. Among these grasses, Sorghum bicolor has been recognized as not only a promising bioenergy crop but also a research model due to its diploidy, simple genome, genetic diversity and clear orthologous relationship with other grass genomes, allowing sorghum research to be easily translated to other grasses. Although sorghum molecular genetic studies have lagged far behind those of major crops (e.g., rice and maize), recent advances have been made in a number of biomass-related traits to dissect the genetic loci and candidate genes, and to discover the functions of key genes. However, molecular and/or targeted breeding toward biomass-related traits in sorghum have not fully benefited from these pieces of genetic knowledge. Thus, to facilitate the breeding and bioenergy applications of sorghum, this perspective summarizes the bioenergy applications of different types of sorghum and outlines the genetic control of the biomass-related traits, ranging from flowering/maturity, plant height, internode morphological traits and metabolic compositions. In particular, we describe the dynamic changes of carbohydrate metabolism in sorghum internodes and highlight the molecular regulators involved in the different stages of internode carbohydrate metabolism, which affects the bioenergy utilization of sorghum biomass. We argue the way forward is to further enhance our understanding of the genetic mechanisms of these biomass-related traits with new technologies, which will lead to future directions toward tailored designing sorghum biomass traits suitable for different bioenergy applications.


Assuntos
Sorghum , Sorghum/genética , Sorghum/metabolismo , Biomassa , Melhoramento Vegetal , Poaceae/genética , Poaceae/metabolismo , Grão Comestível , Combustíveis Fósseis
4.
Phys Chem Chem Phys ; 24(43): 26908-26914, 2022 Nov 09.
Artigo em Inglês | MEDLINE | ID: mdl-36317706

RESUMO

Photocatalytic hydrogen production from water is a sustainable solution to the environmental pollution and energy crises. Encouraged by the successful synthesis of PtS2 and BN nanosheets and their suitable band edges, we have designed a PtS2/BN bilayer heterojunction and investigated its electronic and optical properties for the first time based on hybrid DFT calculations. In this system, the built-in electric field and band edge bending can retain useful electrons on the conduction band of BN and holes on the valence band of PtS2, which endow this system with a stronger redox ability. Meanwhile, this electric field can efficiently separate photoinduced electron-hole pairs and improve the photocatalytic efficiency. Compared with BN and PtS2 single layers, the PtS2/BN heterojunction with its smaller bandgap can make better use of visible and infrared light. Additionally, we have studied the effect of applied strain on the electronic and optical properties. This work aims to provide a method for constructing high-efficiency BN-based photocatalysts and illuminating the electron migration mechanism in step-scheme (S-scheme) heterostructures. We have found that the PtS2/BN bilayer heterojunction is a promising S-scheme photocatalyst for overall water decomposition.

5.
Phys Chem Chem Phys ; 24(41): 25287-25297, 2022 Oct 27.
Artigo em Inglês | MEDLINE | ID: mdl-36226481

RESUMO

Direct Z-scheme water-splitting is a promising route to enhancing the photocatalytic performance due to the effective separation of photogenerated carriers while simultaneously preserving the strong oxidation activity of holes and reduction activity of electrons. In this work, the MoSSe/XY2 (X = Hf, Zr; S, Se) heterostructures (HSs) with different contacts are proposed for Z-scheme photocatalytic water-spitting by first principles calculation. The separation of photogenerated carriers for HfSe2/SMoSe and ZrSe2/SMoSe HSs is limited by the type-I band alignment, while the hydrogen production ability of HfSe2/SeMoS and ZrSe2/SeMoS HSs is limited by the lower conduction band edge positions relative to the water reduction potential. The HfS2/SMoSe, HfS2/SeMoS, ZrS2/SMoSe, and ZrS2/SeMoS HSs are direct Z-scheme water-splitting photocatalysts with the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) occurring at the Hf(Zr)S2 layer and MoSSe layer, respectively. More excitingly, the S (or Se) vacancies effectively lower the HER overpotentials. Besides, the solar-to-hydrogen efficiencies are 6.1%, 5.9%, 6.4%, and 6.3% for HfS2/SMoSe, HfS2/SeMoS, ZrS2/SMoSe, and ZrS2/SeMoS HSs, respectively. This work paves the way for designing highly efficient overall water-splitting photocatalysts using 2D materials.

6.
Int J Mol Sci ; 23(4)2022 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-35216210

RESUMO

The SQUAMOSA-PROMOTER BINDING PROTEIN-LIKE (SPL) gene family affects plant architecture, panicle structure, and grain development, representing key genes for crop improvements. The objective of the present study is to utilize the well characterized SPLs' functions in rice to facilitate the functional genomics of TaSPL genes. To achieve these goals, we combined several approaches, including genome-wide analysis of TaSPLs, comparative genomic analysis, expression profiling, and functional study of TaSPL3 in rice. We established the orthologous relationships of 56 TaSPL genes with the corresponding OsSPLs, laying a foundation for the comparison of known SPL functions between wheat and rice. Some TaSPLs exhibited different spatial-temporal expression patterns when compared to their rice orthologs, thus implicating functional divergence. TaSPL2/6/8/10 were identified to respond to different abiotic stresses through the combination of RNA-seq and qPCR expression analysis. Additionally, ectopic expression of TaSPL3 in rice promotes heading dates, affects leaf and stem development, and leads to smaller panicles and decreased yields per panicle. In conclusion, our work provides useful information toward cataloging of the functions of TaSPLs, emphasized the conservation and divergence between TaSPLs and OsSPLs, and identified the important SPL genes for wheat improvement.


Assuntos
Genoma de Planta/genética , Oryza/genética , Proteínas de Plantas/genética , Triticum/genética , Grão Comestível/genética , Regulação da Expressão Gênica de Plantas/genética , Plantas Geneticamente Modificadas/genética
7.
Phys Chem Chem Phys ; 23(26): 14449-14456, 2021 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-34180927

RESUMO

Hybrid perovskites are favoured over other numerous optoelectronic materials, thanks to their rapidly enhanced power conversion efficiency (PCE) and facile processing. At present, future developments are seriously hampered by the high toxicity of heavy metals and poor stability. Inorganic lead-free perovskites, CsSn1-xGexI3-yBry, are herein explored for superior optical performance by first-principles calculations based on density functional theory (DFT). It is unveiled that the valence band maximum (VBM) is mainly occupied by the p-orbit of halide ions, while the conduction band minimum (CBM) is composed of the p-orbit of the metal ion. Moreover, Bader charge analysis shows that CsSn0.5Ge0.5I3 corresponds to the most obvious charge transfer compared to the others. The defect formation energy indicates that perovskite compounds CsSn1-xGexI3-yBry, are more easily synthesized than the series CsSn1-xGexI3, and the physically accessible area is also determined in the coordinate system defined by the chemical potential change of the host atoms, ΔµSn and ΔµI. Additionally, the absorption spectra show that among the doped compounds of the form CsSn0.5Ge0.5I3-yBry, perovskite CsSn0.5Ge0.5I2Br is superior in terms of optical response in the visible-light range. The results shed a new light on the study of highly efficient and stable lead-free perovskite-based solar cells (PSCs).

8.
BMC Genomics ; 20(1): 287, 2019 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-30975075

RESUMO

BACKGROUND: The trihelix gene family is a plant-specific transcription factor family that plays important roles in plant growth, development, and responses to abiotic stresses. However, to date, no systemic characterization of the trihelix genes has yet been conducted in wheat and its close relatives. RESULTS: We identified a total of 94 trihelix genes in wheat, as well as 22 trihelix genes in Triticum urartu, 29 in Aegilops tauschii, and 31 in Brachypodium distachyon. We analyzed the chromosomal locations and orthology relations of the identified trihelix genes, and no trihelix gene was found to be located on chromosome 7A, 7B, or 7D of wheat, thereby reflecting the uneven distributions of wheat trihelix genes. Phylogenetic analysis indicated that the 186 identified trihelix proteins in wheat, rice, B. distachyon, and Arabidopsis were clustered into five major clades. The trihelix genes belonging to the same clades usually shared similar motif compositions and exon/intron structural patterns. Five pairs of tandem duplication genes and three pairs of segmental duplication genes were identified in the wheat trihelix gene family, thereby validating the supposition that more intrachromosomal gene duplication events occur in the genome of wheat than in that of other grass species. The tissue-specific expression and differential expression profiling of the identified genes under cold and drought stresses were analyzed by using RNA-seq data. qRT-PCR was also used to confirm the expression profiles of ten selected wheat trihelix genes under multiple abiotic stresses, and we found that these genes mainly responded to salt and cold stresses. CONCLUSIONS: In this study, we identified trihelix genes in wheat and its close relatives and found that gene duplication events are the main driving force for trihelix gene evolution in wheat. Our expression profiling analysis demonstrated that wheat trihelix genes responded to multiple abiotic stresses, especially salt and cold stresses. The results of our study built a basis for further investigation of the functions of wheat trihelix genes and provided candidate genes for stress-resistant wheat breeding programs.


Assuntos
Perfilação da Expressão Gênica , Genômica , Proteínas de Plantas/genética , Estresse Fisiológico/genética , Fatores de Transcrição/genética , Triticum/genética , Triticum/fisiologia , Cromossomos de Plantas/genética , Especificidade de Órgãos , Filogenia , Homologia de Sequência do Ácido Nucleico , Sintenia
9.
BMC Plant Biol ; 19(1): 126, 2019 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-30947699

RESUMO

BACKGROUND: Durum wheat is considered not suitable for making many food products that bread wheat can. This limitation is largely due to: (i) lack of grain-hardness controlling genes (Puroindoline a and b) and consequently extremely-hard kernel; (ii) lack of high- and low-molecular-weight glutenin subunit loci (Glu-D1 and Glu-D3) that contribute to gluten strength. To improve food processing quality of durum wheat, we stacked transgenic Pina and HMW-glutenin subunit 1Ax1 in durum wheat and developed lines with medium-hard kernel texture. RESULTS: Here, we demonstrated that co-expression of Pina + 1Ax1 in durum wheat did not affect the milling performance that was enhanced by Pina expression. While stacking of Pina + 1Ax1 led to increased flour yield, finer flour particles and decreased starch damage compared to the control lines. Interestingly, Pina and 1Ax1 co-expression showed synergistic effects on the pasting attribute peak viscosity. Moreover, Pina and 1Ax1 co-expression suggests that PINA impacts gluten aggregation via interaction with gluten protein matrix. CONCLUSIONS: The results herein may fill the gap of grain hardness between extremely-hard durum wheat and the soft kernel durum wheat, the latter of which has been developed recently. Our results may also serve as a proof of concept that stacking Puroindolines and other genes contributing to wheat end-use quality from the A and/or D genomes could improve the above-mentioned bottleneck traits of durum wheat and help to expand its culinary uses.


Assuntos
Glutens/genética , Triticum/genética , Pão , Grão Comestível/genética , Grão Comestível/fisiologia , Dureza , Fenótipo , Proteínas de Plantas/genética , Plantas Geneticamente Modificadas , Triticum/fisiologia
10.
Chemphyschem ; 20(3): 489-498, 2019 02 04.
Artigo em Inglês | MEDLINE | ID: mdl-30548521

RESUMO

Organometal halide perovskites have been outstanding from enormous amount of functional materials thanks to their highly cost-effective processability and prominent light harvesting capacity. Unfortunately, poor long-term stability seriously hinders their further development. The recent experimental observations suggest that Cesium is a promising candidate to enhance the stability of MAPbI3 . To explore the inherent mechanism, a first-principles investigation based on density functional theory, including hybrid functional, has been performed to analyze the electronic and optical properties of perovskite series MA0.75 Cs0.25 PbI3-y Bry . The results indicate that perovskite compound MA0.75 Cs0.25 PbI2 Br is significantly superior to the other doped series in terms of optical absorption within the visible-light range. In the meanwhile, both Bader charge analysis and charge density distribution show that the compound of MA0.75 Cs0.25 PbI2 Br is the most stable among all the doped perovskite series. Moreover, it is clearly manifested that the impact of cesium is mainly embodied in the enhancement of the stability rather than in the improvement of optical absorption. Our study sheds a new light on screening new-type light harvesting materials, and provides theoretical insight into the rationale design of highly efficient and stable photovoltaic devices based on these functional materials.

11.
BMC Genomics ; 19(1): 803, 2018 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-30400808

RESUMO

BACKGROUND: WD40 domains are abundant in eukaryotes, and they are essential subunits of large multiprotein complexes, which serve as scaffolds. WD40 proteins participate in various cellular processes, such as histone modification, transcription regulation, and signal transduction. WD40 proteins are regarded as crucial regulators of plant development processes. However, the systematic identification and analysis of WD40 proteins have yet to be reported in wheat. RESULTS: In this study, a total of 743 WD40 proteins were identified in wheat, and they were grouped into 5 clusters and 11 subfamilies. Their gene structures, chromosomal locations, and evolutionary relationships were analyzed. Among them, 39 and 46 pairs of TaWD40s were distinguished as tandem duplication and segmental duplication genes. The 123 OsWD40s were identified to exhibit synteny with TaWD40s. TaWD40s showed the specific characteristics at the reproductive developmental stage, and numerous TaWD40s were involved in responses to stresses, including cold, heat, drought, and powdery mildew infection pathogen, based on the result of RNA-seq data analysis. The expression profiles of some TaWD40s in wheat seed development were confirmed through qRT-PCR technique. CONCLUSION: In this study, 743 TaWD40s were identified from the wheat genome. As the main driving force of evolution, duplication events were observed, and homologous recombination was another driving force of evolution. The expression profiles of TaWD40s revealed their importance for the growth and development of wheat and their response to biotic and abiotic stresses. Our study also provided important information for further functional characterization of some WD40 proteins in wheat.


Assuntos
Evolução Molecular , Regulação da Expressão Gênica de Plantas , Genoma de Planta , Família Multigênica , Proteínas de Plantas/genética , Triticum/genética , Repetições WD40 , Biologia Computacional , Secas , Perfilação da Expressão Gênica , Filogenia , Regiões Promotoras Genéticas , Estresse Fisiológico , Triticum/crescimento & desenvolvimento
12.
BMC Genomics ; 19(1): 852, 2018 11 29.
Artigo em Inglês | MEDLINE | ID: mdl-30497365

RESUMO

Following the publication of this article [1], the authors reported the following errors.

13.
Planta ; 248(1): 117-137, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29616395

RESUMO

MAIN CONCLUSION: TaGF14b enhances tolerance to multiple stresses through ABA signaling pathway by altering physiological and biochemical processes, including ROS-scavenging system, stomatal closure, compatible osmolytes, and stress-related gene expressions in tobaccos. The 14-3-3 proteins are involved in plant growth, development, and in responding to abiotic stresses. However, the precise functions of 14-3-3s in responding to drought and salt stresses remained unclear, especially in wheat. In this study, a 14-3-3 gene from wheat, designated TaGF14b, was cloned and characterized. TaGF14b was upregulated by polyethylene glycol 6000, sodium chloride, hydrogen peroxide, and abscisic acid (ABA) treatments. Ectopic expression of TaGF14b in tobacco conferred enhanced tolerance to drought and salt stresses. Transgenic tobaccos had longer root, better growth status, and higher relative water content, survival rate, photosynthetic rate, and water use efficiency than control plants under drought and salt stresses. The contribution of TaGF14b to drought and salt tolerance relies on the regulations of ABA biosynthesis and ABA signaling, as well as stomatal closure and stress-related gene expressions. Moreover, TaGF14b expression could significantly enhance the reactive oxygen species (ROS) scavenging system to ameliorate oxidative damage to cells. In addition, TaGF14b increased tolerance to osmotic stress evoked by drought and salinity through modifying water conservation and compatible osmolytes in plants. In conclusion, TaGF14b enhances tolerance to multiple abiotic stresses through the ABA signaling pathway in transgenic tobaccos by altering physiological and biochemical processes.


Assuntos
Proteínas 14-3-3/genética , Triticum/genética , Proteínas 14-3-3/fisiologia , Desidratação , Genes de Plantas/genética , Filogenia , Plantas Geneticamente Modificadas/genética , Tolerância ao Sal , Plantas Tolerantes a Sal/genética , Alinhamento de Sequência , Transdução de Sinais , Nicotiana/genética , Nicotiana/fisiologia , Triticum/fisiologia
14.
Phys Chem Chem Phys ; 20(2): 941-950, 2018 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-29231219

RESUMO

Organic-inorganic hybrid perovskites as new emerging functional materials stand out from numerous photovoltaic materials thanks to the unprecedentedly rapid improvement of their power conversion efficiency within a short period. To explore potentially more efficient photovoltaic candidates, the structural and electronic properties of FAxMA1-xPbI3 based on prototype MAPbI3 are investigated for superior performance. Specifically, structural relaxation is performed at the PBE+D2 level and the electronic and optical properties are investigated at the HSE + SOC level. Optical simulations show that significantly improved performance can be successfully achieved by means of the injection of FA cations. Moreover, the calculations of defect formation energies imply that MA-poor ambient conditions are energetically favorable to synthesize a variety of FA-doped pervoskite compounds FAxMA1-xPbI3 of different ratios. It is interesting to find that compared with the prototype MAPbI3, the optical performance of the perovskite series FAxMA1-xPbI3 is effectively improved with an increase in FA content; meanwhile the relative stability of the perovskite series is also efficiently enhanced. Our study not only sheds new light on further understanding perovskite absorbers but also provides the basic rationale for designing new functional materials used for photovoltaics.

15.
BMC Plant Biol ; 15: 268, 2015 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-26536863

RESUMO

BACKGROUND: NAC (NAM, ATAF, and CUC) transcription factors play important roles in plant biological processes, including phytohormone homeostasis, plant development, and in responses to various environmental stresses. METHODS: TaNAC29 was introduced into Arabidopsis using the Agrobacterium tumefaciens-mediated floral dipping method. TaNAC29-overexpression plants were subjected to salt and drought stresses for examining gene functions. To investigate tolerant mechanisms involved in the salt and drought responses, expression of related marker genes analyses were conducted, and related physiological indices were also measured. Expressions of genes were analyzed by quantitative real-time polymerase chain reaction (qRT-PCR). RESULTS: A novel NAC transcription factor gene, designated TaNAC29, was isolated from bread wheat (Triticum aestivum). Sequence alignment suggested that TaNAC29 might be located on chromosome 2BS. TaNAC29 was localized to the nucleus in wheat protoplasts, and proved to have transcriptional activation activities in yeast. TaNAC29 was expressed at a higher level in the leaves, and expression levels were much higher in senescent leaves, indicating that TaNAC29 might be involved in the senescence process. TaNAC29 transcripts were increased following treatments with salt, PEG6000, H2O2, and abscisic acid (ABA). To examine TaNAC29 function, transgenic Arabidopsis plants overexpressing TaNAC29 were generated. Germination and root length assays of transgenic plants demonstrated that TaNAC29 overexpression plants had enhanced tolerances to high salinity and dehydration, and exhibited an ABA-hypersensitive response. When grown in the greenhouse, TaNAC29-overexpression plants showed the same tolerance response to salt and drought stresses at both the vegetative and reproductive period, and had delayed bolting and flowering in the reproductive period. Moreover, TaNAC29 overexpression plants accumulated lesser malondialdehyde (MDA), H2O2, while had higher superoxide dismutase (SOD) and catalase (CAT) activities under high salinity and/or dehydration stress. CONCLUSIONS: Our results demonstrate that TaNAC29 plays important roles in the senescence process and response to salt and drought stresses. ABA signal pathway and antioxidant enzyme systems are involved in TaNAC29-mediated stress tolerance mechanisms.


Assuntos
Secas , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas/genética , Tolerância ao Sal , Fatores de Transcrição/genética , Triticum/fisiologia , Arabidopsis/genética , Arabidopsis/metabolismo , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/metabolismo , Cloreto de Sódio/metabolismo , Estresse Fisiológico , Fatores de Transcrição/metabolismo , Triticum/genética , Triticum/crescimento & desenvolvimento
16.
BMC Plant Biol ; 15: 112, 2015 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-25943989

RESUMO

BACKGROUND: Lycopene ß-cyclase (LCYB) is a key enzyme catalyzing the biosynthesis of ß-carotene, the main source of provitamin A. However, there is no documented research about this key cyclase gene's function and relationship with ß-carotene content in wheat. Therefore, the objectives of this study were to clone TaLCYB and characterize its function and relationship with ß-carotene biosynthesis in wheat grains. We also aimed to obtain more information about the endogenous carotenoid biosynthetic pathway and thus provide experimental support for carotenoid metabolic engineering in wheat. RESULTS: In the present study, a lycopene ß-cyclase gene, designated TaLCYB, was cloned from the hexaploid wheat cultivar Chinese Spring. The cyclization activity of the encoded protein was demonstrated by heterologous complementation analysis. The TaLCYB gene was expressed differentially in different tissues of wheat. Although TaLCYB had a higher expression level in the later stages of grain development, the ß-carotene content still showed a decreasing tendency. The expression of TaLCYB in leaves was dramatically induced by strong light and the ß-carotene content variation corresponded with changes of TaLCYB expression. A post-transcriptional gene silencing strategy was used to down-regulate the expression of TaLCYB in transgenic wheat, resulting in a decrease in the content of ß-carotene and lutein, accompanied by the accumulation of lycopene to partly compensate for the total carotenoid content. In addition, changes in TaLCYB expression also affected the expression of several endogenous carotenogenic genes to varying degrees. CONCLUSION: Our results suggest that TaLCYB is a genuine lycopene cyclase gene and plays a crucial role in ß-carotene biosynthesis in wheat. Our attempt to silence it not only contributes to elucidating the mechanism of carotenoid accumulation in wheat but may also help in breeding wheat varieties with high provitamin A content through RNA interference (RNAi) to block specific carotenogenic genes in the wheat endosperm.


Assuntos
Liases Intramoleculares/metabolismo , Triticum/metabolismo , Vitamina A/biossíntese , Sequência de Aminoácidos , Clonagem Molecular , Regulação para Baixo , Escherichia coli/genética , Genes de Plantas , Liases Intramoleculares/química , Liases Intramoleculares/genética , Dados de Sequência Molecular , Plantas Geneticamente Modificadas , Homologia de Sequência de Aminoácidos , Triticum/genética , beta Caroteno/metabolismo
17.
J Exp Bot ; 65(9): 2545-56, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24692648

RESUMO

Carotenoid content is a primary determinant of wheat nutritional value and affects its end-use quality. Wheat grains contain very low carotenoid levels and trace amounts of provitamin A content. In order to enrich the carotenoid content in wheat grains, the bacterial phytoene synthase gene (CrtB) and carotene desaturase gene (CrtI) were transformed into the common wheat cultivar Bobwhite. Expression of CrtB or CrtI alone slightly increased the carotenoid content in the grains of transgenic wheat, while co-expression of both genes resulted in a darker red/yellow grain phenotype, accompanied by a total carotenoid content increase of approximately 8-fold achieving 4.76 µg g(-1) of seed dry weight, a ß-carotene increase of 65-fold to 3.21 µg g(-1) of seed dry weight, and a provitamin A content (sum of α-carotene, ß-carotene, and ß-cryptoxanthin) increase of 76-fold to 3.82 µg g(-1) of seed dry weight. The high provitamin A content in the transgenic wheat was stably inherited over four generations. Quantitative PCR analysis revealed that enhancement of provitamin A content in transgenic wheat was also a result of the highly coordinated regulation of endogenous carotenoid biosynthetic genes, suggesting a metabolic feedback regulation in the wheat carotenoid biosynthetic pathway. These transgenic wheat lines are not only valuable for breeding wheat varieties with nutritional benefits for human health but also for understanding the mechanism regulating carotenoid biosynthesis in wheat endosperm.


Assuntos
Proteínas de Bactérias/genética , Carotenoides/biossíntese , Criptoxantinas/biossíntese , Erwinia/enzimologia , Plantas Geneticamente Modificadas/metabolismo , Triticum/metabolismo , beta Caroteno/biossíntese , Proteínas de Bactérias/metabolismo , Vias Biossintéticas , Carotenoides/análise , Criptoxantinas/análise , Erwinia/genética , Plantas Geneticamente Modificadas/química , Plantas Geneticamente Modificadas/genética , Sementes/química , Sementes/genética , Sementes/metabolismo , Triticum/química , Triticum/genética , Vitamina A/análise , Vitamina A/biossíntese , beta Caroteno/análise
18.
Artigo em Inglês | MEDLINE | ID: mdl-38369725

RESUMO

BACKGROUND: Osteosarcoma is the most common primary bone cancer in children and adolescents with high metastatic ability. AIM: This study aimed to explore the inhibitory effects of (S)-10-hydroxycamptothecin (HCPT) on osteosarcoma cell growth and metastasis as well as the underlying mechanism. METHOD: The osteosarcoma cells of 143B and U-2 OS (U-2), treated with HCPT (20, 100, or 300 nM), underwent detections, such as CCK-8, flow cytometry, Transwell, wound healing, and immunoblotting. EMT-related key proteins, like N-cadherin, Snail, and Vimentin, were found to be down-regulated, while E-cadherin was up-regulated dose-dependently in HCPT-exposed 143B and U-2 cells. Additionally, incubation of 143B and U-2 cells with HCPT for 3 hours dosedependently reduced the expression ratios of p-LATS1/LATS1, p-MST1/MST1, p-YAP/YAP, and p-TAZ/TAZ. RESULT: Taken together, our study has demonstrated HCPT to inhibit osteosarcoma growth and metastasis potentially by activating the HIPPO signaling pathway and reversing EMT. CONCLUSION: HCPT might be a candidate agent for the prevention and treatment of osteosarcoma.

19.
J Vis Exp ; (205)2024 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-38587398

RESUMO

Osteosarcoma is the most common primary malignant bone tumor in children and adolescents. Despite the development of new treatment plans in recent years, the prognosis for osteosarcoma patients has not significantly improved. Therefore, it is crucial to establish a robust preclinical model with high fidelity. The patient-derived xenograft (PDX) model faithfully preserves the genetic, epigenetic, and heterogeneous characteristics of human malignancies for each patient. Consequently, PDX models are considered authentic in vivo models for studying various cancers in transformation studies. This article presents a comprehensive protocol for creating and maintaining a PDX mouse model that accurately mirrors the morphological features of human osteosarcoma. This involves the immediate transplantation of freshly resected human osteosarcoma tissue into immunocompromised mice, followed by successive passaging. The described model serves as a platform for studying the growth, drug resistance, relapse, and metastasis of osteosarcoma. Additionally, it aids in screening the target therapeutics and establishing personalized treatment schemes.


Assuntos
Neoplasias Ósseas , Osteossarcoma , Adolescente , Criança , Humanos , Animais , Camundongos , Xenoenxertos , Ensaios Antitumorais Modelo de Xenoenxerto , Recidiva Local de Neoplasia , Osteossarcoma/genética , Osteossarcoma/patologia , Modelos Animais de Doenças , Neoplasias Ósseas/genética , Neoplasias Ósseas/patologia
20.
J Vis Exp ; (208)2024 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-38912794

RESUMO

Decoction formula is the most commonly used dosage form in traditional Chinese medicine and applied in clinical practice for thousands of years by trans-oral administration, which is characterized by quick effect, easy absorption, and individualized treatment based on the specific syndromes of patients. The quality of the decoction formula is directly responsible for the clinical efficacy of traditional Chinese medicine; therefore, the standardization process of the decoction formula is important to avoid differences in decoction quality caused by subjective factors. Meanwhile, due to the limitations of performing clinical experiments, small animals bearing human diseases, such as mice, are often used in medical research to explore the therapeutic efficacy and comprehensive mechanisms of different interventions, including the decoction formula for traditional Chinese medicine. Consequently, as an important trans-oral administration method, the skilled gavage technique is particularly important to avoid potential esophagus damage and drug spillage, which will ensure an equal amount of medicine being administered to each model animal, leading to accurate experimental results. Furthermore, the standardized method of decoction formula preparation and skilled gavage strategy are necessary to protect animal welfare and minimize the number of animals used. Here, we reported a detailed standardization process of the decoction formula and gavage technique with Yiqi Jiedu decoction in osteosarcoma mouse model as an example. The efficacy was evaluated by the tumor volume. This protocol will maximize animal protection and improve the reliability of research data, therefore providing effective strategies for future investigating therapeutic efficacy and molecular mechanisms of decoction formula for traditional Chinese medicine in vivo.


Assuntos
Medicamentos de Ervas Chinesas , Medicina Tradicional Chinesa , Osteossarcoma , Animais , Osteossarcoma/tratamento farmacológico , Osteossarcoma/patologia , Camundongos , Medicamentos de Ervas Chinesas/administração & dosagem , Medicina Tradicional Chinesa/métodos , Neoplasias Ósseas/tratamento farmacológico , Neoplasias Ósseas/patologia , Modelos Animais de Doenças , Administração Oral
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