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1.
Small ; 20(5): e2305579, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37788902

RESUMO

The photothermal process has attracted considerable attention in water treatment due to its advantages of low energy consumption and high efficiency. In this respect, photothermal materials play a crucial role in the photothermal process. Particularly, carbonaceous materials have emerged as promising candidates for this process because of exceptional photothermal performance. While previous research on carbonaceous materials has primarily focused on photothermal evaporation and sterilization, there is now a growing interest in exploring the potential of photothermal effect-assisted advanced oxidation processes (AOPs). However, the underlying mechanism of the photothermal effect assisted by carbonaceous materials remains unclear. This review aims to provide a comprehensive review of the photothermal process of carbonaceous materials in water treatment. It begins by introducing the photothermal properties of carbonaceous materials, followed by a discussion on strategies for enhancing these properties. Then, the application of carbonaceous materials-based photothermal process for water treatment is summarized. This includes both direct photothermal processes such as photothermal evaporation and sterilization, as well as indirect photothermal processes that assisted AOPs. Meanwhile, various mechanisms assisted by the photothermal effect are summarized. Finally, the challenges and opportunities of using carbonaceous materials-based photothermal processes for water treatment are proposed.

2.
Small ; 20(7): e2306621, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37814375

RESUMO

Future renewable energy supply and green, sustainable environmental development rely on various types of catalytic reactions. Copper single-atom catalysts (Cu SACs) are attractive due to their distinctive electronic structure (3d orbitals are not filled with valence electrons), high atomic utilization, and excellent catalytic performance and selectivity. Despite numerous optimization studies are conducted on Cu SACs in terms of energy conversion and environmental purification, the coupling among Cu atoms-support interactions, active sites, and catalytic performance remains unclear, and a systematic review of Cu SACs is lacking. To this end, this work summarizes the recent advances of Cu SACs. The synthesis strategies of Cu SACs, metal-support interactions between Cu single atoms and different supports, modification methods including modification for carriers, coordination environment regulating, site distance effect utilizing, and dual metal active center catalysts constructing, as well as their applications in energy conversion and environmental purification are emphatically introduced. Finally, the opportunities and challenges for the future Cu SACs development are discussed. This review aims to provide insight into Cu SACs and a reference for their optimal design and wide application.

3.
Inorg Chem ; 63(20): 9315-9325, 2024 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-38723026

RESUMO

Highly crystalline ZSM-23 zeolite, exhibiting a distinctive dumbbell morphology, was synthesized via a hydrothermal method. Bifunctional catalysts, comprising single metals (Pt or Au) and bimetals (Pt-Au), were successfully prepared by using a positional precipitation method. The hydroisomerization of hexadecane served as a model reaction to assess the catalytic performance arising from the synergistic effects of bimetallic active sites. In comparison to single-metal catalysts, 0.3Au0.7Pt/ZSM-23 demonstrated increased n-C16 conversion, while 0.5Au0.5Pt/ZSM-23 exhibited enhanced i-C16 selectivity, achieving the highest i-C16 yield. The bimetallic catalyst not only finely tuned the metal site activity through bimetallic synergy but also achieved a superior balance between metal and acid catalysis, resulting in improved catalytic performance in the n-C16 hydroisomerization. The Pt-Au bimetallic catalyst approached the ideal requirements for a hydroisomerization catalyst, achieving a harmonious balance of metal and acid catalysis.

4.
Int J Mol Sci ; 24(16)2023 Aug 09.
Artigo em Inglês | MEDLINE | ID: mdl-37628762

RESUMO

Phoebe bournei is nationally conserved in China due to its high economic value and positive effect on the ecological environment. P. bournei has an excellent wood structure, making it useful for industrial and domestic applications. Despite its importance, there are only a few studies on the lateral organ boundary domain (LBD) genes in P. bournei. The LBD gene family contributes to prompting rooting in multiple plant species and therefore supports their survival directly. To understand the LBD family in P. bournei, we verified its characteristics in this article. By comparing the sequences of Arabidopsis and identifying conserved domains and motifs, we found that there were 38 members of the LBD family in P. bournei, which were named PbLBD1 to PbLBD38. Through evolutionary analysis, we found that they were divided into two different populations and five subfamilies in total. The LBD gene family in P. bournei (Hemsl.) Yang species had two subfamilies, including 32 genes in Class I and 6 genes in Class II. It mainly consists of a Lateral Organ Boundary (LOB) conservative domain, and the protein structure is mostly "Y"-shaped. The gene expression pattern of the LBD gene family showed that the LBD genes were mainly expressed in lateral organs of plants, such as flowers and fruits. The response of LBD transcription factors to red and blue light was summarized, and several models of optogenetic expression regulation were proposed. The effect of regulatory mechanisms on plant rooting was also predicted. Moreover, quantitative real-time PCR (qRT-PCR) revealed that most PbLBDs were differentially expressed under cold, heat, drought, and salt stresses, indicating that PbLBDs might play different functions depending on the type of abiotic stress. This study provides the foundation for further research on the function of LBD in this tree species in the future.


Assuntos
Arabidopsis , Lauraceae , Evolução Biológica , China , Secas
5.
Plant J ; 105(1): 182-196, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33107656

RESUMO

Production of hydroxy fatty acids (HFAs) in transgenic crops represents a promising strategy to meet our demands for specialized plant oils with industrial applications. The expression of Ricinus communis (castor) OLEATE 12-HYDROXYLASE (RcFAH12) in Arabidopsis has resulted in only limited accumulation of HFAs in seeds, which probably results from inefficient transfer of HFAs from their site of synthesis (phosphatidylcholine; PC) to triacylglycerol (TAG), especially at the sn-1/3 positions of TAG. Phospholipase As (PLAs) may be directly involved in the liberation of HFAs from PC, but the functions of their over-expression in HFA accumulation and distribution at TAG in transgenic plants have not been well studied. In this work, the functions of lecithin:cholesterol acyltransferase-like PLAs (LCAT-PLAs) in HFA biosynthesis were characterized. The LCAT-PLAs were shown to exhibit homology to LCAT and mammalian lysosomal PLA2 , and to contain a conserved and functional Ser/His/Asp catalytic triad. In vitro assays revealed that LCAT-PLAs from the HFA-accumulating plant species Physaria fendleri (PfLCAT-PLA) and castor (RcLCAT-PLA) could cleave acyl chains at both the sn-1 and sn-2 positions of PC, and displayed substrate selectivity towards sn-2-ricinoleoyl-PC over sn-2-oleoyl-PC. Furthermore, co-expression of RcFAH12 with PfLCAT-PLA or RcLCAT-PLA, but not Arabidopsis AtLCAT-PLA, resulted in increased occupation of HFA at the sn-1/3 positions of TAG as well as small but insignificant increases in HFA levels in Arabidopsis seeds compared with RcFAH12 expression alone. Therefore, PfLCAT-PLA and RcLCAT-PLA may contribute to HFA turnover on PC, and represent potential candidates for engineering the production of unusual fatty acids in crops.


Assuntos
Brassicaceae/enzimologia , Fosfatidilcolina-Esterol O-Aciltransferase/metabolismo , Fosfatidilcolinas/metabolismo , Proteínas de Plantas/metabolismo , Ricinus/enzimologia , Arabidopsis/metabolismo , Brassicaceae/genética , Ácidos Graxos/metabolismo , Lisofosfolipídeos , Fosfatidilcolina-Esterol O-Aciltransferase/genética , Proteínas de Plantas/genética , Raízes de Plantas/metabolismo , Plantas Geneticamente Modificadas , Estrutura Terciária de Proteína , Ricinus/genética , Sementes/metabolismo , Especificidade por Substrato
6.
BMC Plant Biol ; 22(1): 153, 2022 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-35350998

RESUMO

BACKGROUND: Seed storage lipids are valuable for human diet and for the sustainable development of mankind. In recent decades, many lipid metabolism genes and pathways have been identified, but the molecular mechanisms that underlie differences in seed oil biosynthesis in species with developed embryo and endosperm are not fully understood. RESULTS: We performed comparative genome and transcriptome analyses of castor bean and rapeseed, which have high seed oil contents, and maize, which has a low seed oil content. These results revealed the molecular underpinnings of the low seed oil content in maize. First of all, transcriptome analyses showed that more than 61% of the lipid- and carbohydrate-related genes were regulated in castor bean and rapeseed, but only 20.1% of the lipid-related genes and 22.5% of the carbohydrate-related genes were regulated in maize. Then, compared to castor bean and rapeseed, fewer lipid biosynthesis genes but more lipid metabolism genes were regulated in the maize embryo. More importantly, most maize genes encoding lipid-related transcription factors, triacylglycerol (TAG) biosynthetic enzymes, pentose phosphate pathway (PPP) and Calvin Cycle proteins were not regulated during seed oil synthesis, despite the presence of many homologs in the maize genome. Additionally, we observed differential regulation of vital oil biosynthetic enzymes and extremely high expression levels of oil biosynthetic genes in castor bean, which were consistent with the rapid accumulation of oil in castor bean developing seeds. CONCLUSIONS: Compared to high-oil seeds (castor bean and rapeseed), less oil biosynthetic genes were regulated during the seed development in low-oil seed (maize). These results shed light on molecular mechanisms of lipid biosynthesis in maize, castor bean, and rapeseed. They can provide information on key target genes that may be useful for future experimental manipulation of oil production in oil plants.


Assuntos
Brassica napus , Ricinus communis , Brassica napus/genética , Ricinus communis/genética , Óleos de Plantas/metabolismo , Sementes , Transcriptoma , Zea mays/genética , Zea mays/metabolismo
7.
Int J Mol Sci ; 23(14)2022 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-35887387

RESUMO

Heat shock transcription factors (HSFs) activate heat shock protein gene expression by binding their promoters in response to heat stress and are considered to be pivotal transcription factors in plants. Eucalyptus is a superior source of fuel and commercial wood. During its growth, high temperature or other abiotic stresses could impact its defense capability and growth. Hsf genes have been cloned and sequenced in many plants, but rarely in Eucalyptus. In this study, we used bioinformatics methods to analyze and identify Eucalyptus Hsf genes, their chromosomal localization and structure. The phylogenetic relationship and conserved domains of their encoded proteins were further analyzed. A total of 36 Hsf genes were identified and authenticated from Eucalyptus, which were scattered across 11 chromosomes. They could be classified into three classes (A, B and C). Additionally, a large number of stress-related cis-regulatory elements were identified in the upstream promoter sequence of HSF, and cis-acting element analysis indicated that the expression of EgHsf may be regulated by plant growth and development, metabolism, hormones and stress responses. The expression profiles of five representative Hsf genes, EgHsf4, EgHsf9, EgHsf13, EgHsf24 and EgHsf32, under salt and temperature stresses were examined by qRT-PCR. The results show that the expression pattern of class B genes (EgHsf4, EgHsf24 and EgHsf32) was more tolerant to abiotic stresses than that of class A genes (EgHsf9 and EgHsf13). However, the expressions of all tested Hsf genes in six tissues were at different levels. Finally, we investigated the network of interplay between genes, and the results suggest that there may be synergistic effects between different Hsf genes in response to abiotic stresses. We conclude that the Hsf gene family played an important role in the growth and developmental processes of Eucalyptus and could be vital for maintaining cell homeostasis against external stresses. This study provides basic information on the members of the Hsf gene family in Eucalyptus and lays the foundation for the functional identification of related genes and the further investigation of their biological functions in plant stress regulation.


Assuntos
Eucalyptus , Eucalyptus/genética , Eucalyptus/metabolismo , Regulação da Expressão Gênica de Plantas , Fatores de Transcrição de Choque Térmico/genética , Fatores de Transcrição de Choque Térmico/metabolismo , Filogenia , Proteínas de Plantas/metabolismo , Cloreto de Sódio/metabolismo , Estresse Fisiológico/genética , Temperatura
8.
Plant Physiol ; 182(2): 739-755, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31792147

RESUMO

The triacylglycerols (TAGs; i.e. oils) that accumulate in plants represent the most energy-dense form of biological carbon storage, and are used for food, fuels, and chemicals. The increasing human population and decreasing amount of arable land have amplified the need to produce plant oil more efficiently. Engineering plants to accumulate oils in vegetative tissues is a novel strategy, because most plants only accumulate large amounts of lipids in the seeds. Recently, tobacco (Nicotiana tabacum) leaves were engineered to accumulate oil at 15% of dry weight due to a push (increased fatty acid synthesis)-and-pull (increased final step of TAG biosynthesis) engineering strategy. However, to accumulate both TAG and essential membrane lipids, fatty acid flux through nonengineered reactions of the endogenous metabolic network must also adapt, which is not evident from total oil analysis. To increase our understanding of endogenous leaf lipid metabolism and its ability to adapt to metabolic engineering, we utilized a series of in vitro and in vivo experiments to characterize the path of acyl flux in wild-type and transgenic oil-accumulating tobacco leaves. Acyl flux around the phosphatidylcholine acyl editing cycle was the largest acyl flux reaction in wild-type and engineered tobacco leaves. In oil-accumulating leaves, acyl flux into the eukaryotic pathway of glycerolipid assembly was enhanced at the expense of the prokaryotic pathway. However, a direct Kennedy pathway of TAG biosynthesis was not detected, as acyl flux through phosphatidylcholine preceded the incorporation into TAG. These results provide insight into the plasticity and control of acyl lipid metabolism in leaves.


Assuntos
Lipídeos de Membrana/metabolismo , Engenharia Metabólica/métodos , Nicotiana/metabolismo , Folhas de Planta/metabolismo , Óleos de Plantas/metabolismo , Plantas Geneticamente Modificadas/metabolismo , Triglicerídeos/metabolismo , Aciltransferases/genética , Aciltransferases/metabolismo , Ácidos Graxos/metabolismo , Regulação da Expressão Gênica de Plantas , Metabolismo dos Lipídeos , Redes e Vias Metabólicas , Microssomos/metabolismo , Nicotiana/genética , Triglicerídeos/biossíntese
9.
J Exp Bot ; 72(2): 385-397, 2021 02 02.
Artigo em Inglês | MEDLINE | ID: mdl-33045083

RESUMO

Nitric oxide (NO) is a key signaling molecule regulating several plant developmental and stress responses. Here, we report that NO plays an important role in seed oil content and fatty acid composition. RNAi silencing of Arabidopsis S-nitrosoglutathione reductase 1 (GSNOR1) led to reduced seed oil content. In contrast, nitrate reductase double mutant nia1nia2 had increased seed oil content, compared with wild-type plants. Moreover, the concentrations of palmitic acid (C16:0), linoleic acid (C18:2), and linolenic acid (C18:3) were higher, whereas those of stearic acid (C18:0), oleic acid (C18:1), and arachidonic acid (C20:1) were lower, in seeds of GSNOR1 RNAi lines. Similar results were obtained with rapeseed embryos cultured in vitro with the NO donor sodium nitroprusside (SNP), and the NO inhibitor NG-Nitro-L-arginine Methyl Ester (L-NAME). Compared with non-treated embryos, the oil content decreased in SNP-treated embryos, and increased in L-NAME-treated embryos. Relative concentrations of C16:0, C18:2 and C18:3 were higher, whereas C18:1 concentration decreased in rapeseed embryos treated with SNP. Proteomics and transcriptome analysis revealed that three S-nitrosated proteins and some key genes involved in oil synthesis, were differentially regulated in SNP-treated embryos. Therefore, regulating NO content could be a novel approach to increasing seed oil content in cultivated oil crops.


Assuntos
Ácidos Graxos , Óxido Nítrico , Nitrosação , Óleos de Plantas , Proteína S , Sementes
10.
Int J Mol Sci ; 22(23)2021 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-34884791

RESUMO

In seed-bearing plants, the ovule ("small egg") is the organ within the gynoecium that develops into a seed after fertilization. The gynoecium located in the inner compartment of the flower turns into a fruit. The number of ovules in the ovary determines the upper limit or the potential of seed number per fruit in plants, greatly affecting the final seed yield. Ovule number is an important adaptive characteristic for plant evolution and an agronomic trait for crop improvement. Therefore, understanding the mechanism and pathways of ovule number regulation becomes a significant research aspect in plant science. This review summarizes the ovule number regulators and their regulatory mechanisms and pathways. Specially, an integrated molecular network for ovule number regulation is constructed, in which phytohormones played a central role, followed by transcription factors, enzymes, other protein and micro-RNA. Of them, AUX, BR and CK are positive regulator of ovule number, whereas GA acts negatively on it. Interestingly, many ovule number regulators have conserved functions across several plant taxa, which should be the targets of genetic improvement via breeding or gene editing. Many ovule number regulators identified to date are involved in the diverse biological process, such as ovule primordia formation, ovule initiation, patterning, and morphogenesis. The relations between ovule number and related characteristics/traits especially of gynoecium/fruit size, ovule fertility, and final seed number, as well as upcoming research questions, are also discussed. In summary, this review provides a general overview of the present finding in ovule number regulation, which represents a more comprehensive and in-depth cognition on it.


Assuntos
Arabidopsis/anatomia & histologia , Óvulo Vegetal/anatomia & histologia , Reguladores de Crescimento de Plantas/metabolismo , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Regulação da Expressão Gênica de Plantas/genética , Óvulo Vegetal/genética , Reguladores de Crescimento de Plantas/genética , Sementes/citologia , Fatores de Transcrição/metabolismo
11.
Plant Cell Physiol ; 61(7): 1335-1347, 2020 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-32379869

RESUMO

Alpha-linolenic acid (ALA, 18:3Δ9,12,15) and γ-linolenic acid \ (GLA, 18:3Δ6,9,12) are important trienoic fatty acids, which are beneficial for human health in their own right, or as precursors for the biosynthesis of long-chain polyunsaturated fatty acids. ALA and GLA in seed oil are synthesized from linoleic acid (LA, 18:2Δ9,12) by the microsomal ω-3 fatty acid desaturase (FAD3) and Δ6 desaturase (D6D), respectively. Cotton (Gossypium hirsutum L.) seed oil composition was modified by transforming with an FAD3 gene from Brassica napus and a D6D gene from Echium plantagineum, resulting in approximately 30% ALA and 20% GLA, respectively. The total oil content in transgenic seeds remained unaltered relative to parental seeds. Despite the use of a seed-specific promoter for transgene expression, low levels of GLA and increased levels of ALA were found in non-seed cotton tissues. At low temperature, the germinating cottonseeds containing the linolenic acid isomers elongated faster than the untransformed controls. ALA-producing lines also showed higher photosynthetic rates at cooler temperature and better fiber quality compared to both untransformed controls and GLA-producing lines. The oxidative stability of the novel cottonseed oils was assessed, providing guidance for potential food, pharmaceutical and industrial applications of these oils.


Assuntos
Fibra de Algodão , Óleo de Sementes de Algodão/metabolismo , Germinação/genética , Gossypium/genética , Fotossíntese/genética , Sementes/crescimento & desenvolvimento , Ácido alfa-Linolênico/metabolismo , Ácido gama-Linolênico/metabolismo , Brassica napus/genética , Resposta ao Choque Frio , Fibra de Algodão/normas , Ácidos Graxos Dessaturases/genética , Ácidos Graxos Dessaturases/metabolismo , Engenharia Genética , Gossypium/metabolismo , Plantas Geneticamente Modificadas , Sementes/metabolismo , Ácido alfa-Linolênico/genética , Ácido gama-Linolênico/genética
12.
Appl Environ Microbiol ; 86(18)2020 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-32680871

RESUMO

Researchers have long endeavored to accumulate triacylglycerols (TAGs) or their derivatives in easily managed microbes. The attempted production of TAGs in Escherichia coli has revealed barriers to the broad applications of this technology, including low TAG productivity and slow cell growth. We have demonstrated that an acyl-CoA-independent pathway can divert phospholipid flux into TAG formation in E. coli mediated by Chlamydomonas reinhardtii phospholipid:diacylglycerol acyltransferase (CrPDAT) without interfering with membrane functions. We then showed the synergistic effect on TAG accumulation via the acyl-CoA-independent pathway mediated by PDAT and the acyl-CoA-dependent pathway mediated by wax ester synthase/acyl-CoA:diacylglycerol acyltransferase (WS/DGAT). Furthermore, CrPDAT led to synchronous TAG accumulation during cell growth, and this could be enhanced by supplementation of arbutin. We also showed that rationally mutated CrPDAT was capable of decreasing TAG lipase activity without impairing PDAT activity. Finally, ScPDAT from Saccharomyces cerevisiae exhibited similar activities as CrPDAT in E. coli Our results suggest that the improvement in accumulation of TAGs and their derivatives can be achieved by fine-tuning of phospholipid metabolism in E. coli Understanding the roles of PDAT in the conversion of phospholipids into TAGs during the logarithmic growth phase may enable a novel strategy for the production of microbial oils.IMPORTANCE Although phospholipid:diacylglycerol acyltransferase (PDAT) activity is presumed to exist in prokaryotic oleaginous bacteria, the corresponding gene has not been identified yet. In this article, we have demonstrated that an acyl-CoA-independent pathway can divert phospholipid flux into TAG formation in Escherichia coli mediated by exogenous CrPDAT from Chlamydomonas reinhardtii without interfering with membrane functions. In addition, the acyl-CoA-independent pathway and the acyl-CoA-dependent pathway had the synergistic effect on TAG accumulation. Overexpression of CrPDAT led to synchronous TAG accumulation during cell growth. In particular, CrPDAT possessed multiple catalytic activities, and the rational mutation of CrPDAT led to the decrease of TAG lipase activity without impairing acyltransferase activity. The present findings suggested that applying PDAT in E. coli or other prokaryotic microbes may be a promising strategy for accumulation of TAGs and their derivatives.


Assuntos
Acil Coenzima A/metabolismo , Aciltransferases/metabolismo , Escherichia coli/enzimologia , Ácidos Graxos/metabolismo , Fosfolipídeos/metabolismo , Triglicerídeos/metabolismo , Redes e Vias Metabólicas
13.
Plant Cell Physiol ; 60(6): 1197-1204, 2019 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-31076774

RESUMO

The seed oil quality of Brassica oilseed species has been improved in the last few decades, using conventional breeding approaches. Modern biotechnology has enabled the significant development of new seed lipid traits in many oil crops. Alternation of seed lipid component with gene knockout by RNAi gene silencing, artificial microRNA or gene editing within the crop is relative straightforward. Introducing a new pathway from an exogenous source via biotechnology enables the creation of a new trait, where the biosynthetic pathway for such a new trait is not available in the host crop. This review updates the recent development of new seed lipid traits in six major Brassica species and highlights the capability of biotechnology to improve the composition of important fatty acids for both industrial and nutritional purposes.


Assuntos
Brassica/genética , Engenharia Genética , Característica Quantitativa Herdável , Óleo de Brassica napus/metabolismo , Sementes/metabolismo , Brassica/metabolismo , Edição de Genes , Engenharia Genética/métodos
14.
Plant Biotechnol J ; 17(1): 220-232, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-29873878

RESUMO

Synthesis and accumulation of the storage lipid triacylglycerol in vegetative plant tissues has emerged as a promising strategy to meet the world's future need for vegetable oil. Sorghum (Sorghum bicolor) is a particularly attractive target crop given its high biomass, drought resistance and C4 photosynthesis. While oilseed-like triacylglycerol levels have been engineered in the C3 model plant tobacco, progress in C4 monocot crops has been lagging behind. In this study, we report the accumulation of triacylglycerol in sorghum leaf tissues to levels between 3 and 8.4% on a dry weight basis depending on leaf and plant developmental stage. This was achieved by the combined overexpression of genes encoding the Zea mays WRI1 transcription factor, Umbelopsis ramanniana UrDGAT2a acyltransferase and Sesamum indicum Oleosin-L oil body protein. Increased oil content was visible as lipid droplets, primarily in the leaf mesophyll cells. A comparison between a constitutive and mesophyll-specific promoter driving WRI1 expression revealed distinct changes in the overall leaf lipidome as well as transitory starch and soluble sugar levels. Metabolome profiling uncovered changes in the abundance of various amino acids and dicarboxylic acids. The results presented here are a first step forward towards the development of sorghum as a dedicated biomass oil crop and provide a basis for further combinatorial metabolic engineering.


Assuntos
Lipídeos/biossíntese , Folhas de Planta/metabolismo , Óleos de Plantas/análise , Sorghum/metabolismo , Aminoácidos/análise , Aminoácidos/metabolismo , Metabolismo dos Lipídeos , Lipídeos/análise , Folhas de Planta/química , Óleos de Plantas/metabolismo , Plantas Geneticamente Modificadas/metabolismo , Sorghum/química , Amido/análise , Amido/metabolismo , Triglicerídeos/metabolismo , Regulação para Cima
15.
Int J Mol Sci ; 20(12)2019 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-31234541

RESUMO

Omega-3 long chain polyunsaturated fatty acids (ω3 LC-PUFAs) such as eicosapentaenoic acid (EPA; 20:5ω3) and docosahexaenoic acid (DHA; 22:6ω3) are important fatty acids for human health. These ω3 LC-PUFAs are produced from their ω3 precursors by a set of desaturases and elongases involved in the biosynthesis pathway and are also converted from ω6 LC-PUFA by omega-3 desaturases (ω3Ds). Here, we have investigated eight ω3-desaturases obtained from a cyanobacterium, plants, fungi and a lower animal species for their activities and compared their specificities for various C18, C20 and C22 ω6 PUFA substrates by transiently expressing them in Nicotiana benthamiana leaves. Our results showed hitherto unreported activity of many of the ω3Ds on ω6 LC-PUFA substrates leading to their conversion to ω3 LC-PUFAs. This discovery could be important in the engineering of EPA and DHA in heterologous hosts.


Assuntos
Ácidos Graxos Dessaturases/metabolismo , Ácidos Graxos Ômega-3/metabolismo , Animais , Cianobactérias/enzimologia , Fungos/enzimologia , Plantas/enzimologia , Plantas Geneticamente Modificadas , Especificidade por Substrato , Nicotiana/genética
16.
Int J Mol Sci ; 20(6)2019 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-30909528

RESUMO

Research has shown that nano-copper (nano-Cu) can cause damage to the spleen and immune system yet their mechanisms of cytotoxicity are poorly understood. Our aim is to explore the potential immunotoxicity in the spleen of rats after nano-Cu exposure. The results of hematologic parameters, lymphocyte subsets, immunoglobulins, and histopathology indicated that copper obviously changed the immune function of the spleen. The levels of antioxidants (SOD, CAT, GSH-Px), oxidants (iNOS, NO, MDA), and anti-oxidative signalling pathway of Nrf2 (Nrf2 and HO-1) were strongly induced by nano-Cu. The expression of mRNA and protein of pro-/anti-inflammatory (IFN-γ, TNF-α, MIP-1α, MCP-1, MIF, IL-1/-2/-4/-6) cytokines were increased by nano-Cu. The expression of regulatory signal pathways, MAPKs and PI3-K/Akt were activated, which might be involved in the inflammatory responses and immunomodulatory processes of sub-acute nano-Cu exposure. The immune function of the spleen was repressed by nano-Cu induced oxidative stress and inflammation.


Assuntos
Cobre/toxicidade , Nanopartículas Metálicas , Baço/efeitos dos fármacos , Animais , Biomarcadores , Cobre/química , Cobre/metabolismo , Expressão Gênica , Masculino , Estresse Oxidativo , Ratos , Baço/metabolismo , Testes de Toxicidade
17.
Plant Biotechnol J ; 16(10): 1788-1796, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-29509999

RESUMO

Vegetable oils extracted from oilseeds are an important component of foods, but are also used in a range of high value oleochemical applications. Despite being biodegradable, nontoxic and renewable current plant oils suffer from the presence of residual polyunsaturated fatty acids that are prone to free radical formation that limit their oxidative stability, and consequently shelf life and functionality. Many decades of plant breeding have been successful in raising the oleic content to ~90%, but have come at the expense of overall field performance, including poor yields. Here, we engineer superhigh oleic (SHO) safflower producing a seed oil with 93% oleic generated from seed produced in multisite field trials spanning five generations. SHO safflower oil is the result of seed-specific hairpin-based RNA interference of two safflower lipid biosynthetic genes, FAD2.2 and FATB, producing seed oil containing less than 1.5% polyunsaturates and only 4% saturates but with no impact on lipid profiles of leaves and roots. Transgenic SHO events were compared to non-GM safflower in multisite trial plots with a wide range of growing season conditions, which showed no evidence of impact on seed yield. The oxidative stability of the field-grown SHO oil produced from various sites was 50 h at 110°C compared to 13 h for conventional ~80% oleic safflower oils. SHO safflower produces a uniquely stable vegetable oil across different field conditions that can provide the scale of production that is required for meeting the global demands for high stability oils in food and the oleochemical industry.


Assuntos
Carthamus tinctorius/metabolismo , Ácidos Oleicos/metabolismo , Interferência de RNA , Óleo de Cártamo/química , Sementes/metabolismo , Carthamus tinctorius/genética , Oxirredução
18.
J Pharmacol Exp Ther ; 363(2): 176-183, 2017 11.
Artigo em Inglês | MEDLINE | ID: mdl-28855373

RESUMO

Chronic pain, often defined as any pain lasting more than 3 months, is poorly managed because of its multifaceted and complex mechanisms. Calcium/calmodulin-dependent protein kinase II (CaMKII) is a multifunctional serine/threonine kinase that plays a fundamental role in synaptic plasticity, learning, and memory. Recent emerging evidence demonstrates increased expression and activity of CaMKII in the spinal cord and dorsal root ganglia of various chronic pain models. Moreover, our previous studies also find that inhibiting CaMKII could attenuate inflammatory pain and neuropathic pain. In this review, we provide evidence for the involvement of CaMKII in the initiation and development of chronic pain, including neuropathic pain, bone cancer pain, and inflammatory pain. Novel CaMKII inhibitors with potent inhibitory effect and high specificity may be alternative therapeutic strategies for the management of chronic pain in the future.


Assuntos
Proteína Quinase Tipo 2 Dependente de Cálcio-Calmodulina/metabolismo , Dor Crônica/enzimologia , Dor Crônica/patologia , Animais , Neoplasias Ósseas/complicações , Dor Crônica/etiologia , Humanos , Neuralgia/enzimologia , Neuralgia/patologia
20.
Metab Eng ; 39: 237-246, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27993560

RESUMO

Synthesis and accumulation of plant oils in the entire vegetative biomass offers the potential to deliver yields surpassing those of oilseed crops. However, current levels still fall well short of those typically found in oilseeds. Here we show how transcriptome and biochemical analyses pointed to a futile cycle in a previously established Nicotiana tabacum line, accumulating up to 15% (dry weight) of the storage lipid triacylglycerol in leaf tissue. To overcome this metabolic bottleneck, we either silenced the SDP1 lipase or overexpressed the Arabidopsis thaliana LEC2 transcription factor in this transgenic background. Both strategies independently resulted in the accumulation of 30-33% triacylglycerol in leaf tissues. Our results demonstrate that the combined optimization of de novo fatty acid biosynthesis, storage lipid assembly and lipid turnover in leaf tissue results in a major overhaul of the plant central carbon allocation and lipid metabolism. The resulting further step changes in oil accumulation in the entire plant biomass offers the possibility of delivering yields that outperform current oilseed crops.


Assuntos
Melhoramento Genético/métodos , Engenharia Metabólica/métodos , Redes e Vias Metabólicas/fisiologia , Nicotiana/fisiologia , Folhas de Planta/fisiologia , Óleos de Plantas/metabolismo , Arabidopsis/fisiologia , Proteínas de Arabidopsis/genética , Óleos de Plantas/isolamento & purificação , Fatores de Transcrição/genética
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