Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 58
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Int J Mol Sci ; 20(7)2019 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-30978911

RESUMO

Lepidium sativum L. is a rich source of polyphenols that have huge medicinal and pharmaceutical applications. In the current study, an effective abiotic elicitation strategy was designed for enhanced biosynthesis of polyphenols in callus culture of L. sativum. Callus was exposed to UV-C radiations for different time intervals and various concentrations of melatonin. Secondary metabolites were quantified by using high-performance liquid chromatography (HPLC). Results indicated the total secondary metabolite accumulation of nine quantified compounds was almost three fold higher (36.36 mg/g dry weight (DW)) in melatonin (20 µM) treated cultures, whereas, in response to UV-C (60 min), a 2.5 fold increase (32.33 mg/g DW) was recorded compared to control (13.94 mg/g DW). Metabolic profiling revealed the presence of three major phytochemicals, i.e., chlorogenic acid, kaemferol, and quercetin, in callus culture of L. sativum. Furthermore, antioxidant, antidiabetic, and enzymatic activities of callus cultures were significantly enhanced. Maximum antidiabetic activities (α-glucosidase: 57.84%; α-amylase: 62.66%) were recorded in melatonin (20 µM) treated callus cultures. Overall, melatonin proved to be an effect elicitor compared to UV-C and a positive correlation in these biological activities and phytochemical accumulation was observed. The present study provides a better comparison of both elicitors and their role in the initiation of physiological pathways for enhanced metabolites biosynthesis in vitro callus culture of L. sativum.


Assuntos
Antioxidantes/metabolismo , Vias Biossintéticas/efeitos da radiação , Hipoglicemiantes/metabolismo , Lepidium sativum/metabolismo , Lepidium sativum/efeitos da radiação , Melatonina/metabolismo , Flavonoides/metabolismo , Lepidium sativum/enzimologia , Metaboloma/efeitos da radiação , Fenóis/metabolismo , Proteínas de Plantas/metabolismo , Metabolismo Secundário/efeitos da radiação , Raios Ultravioleta
2.
Plant Physiol Biochem ; 134: 113-122, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30448024

RESUMO

Organisms suffer more harmful ultraviolet radiation in the Antarctica due to the ozone layer destruction. Bryophytes are the dominant flora in the Antarctic continent. However, the molecular mechanism of Antarctic moss adaptation to UV-B radiation remains unclear. In the research, the transcriptional profiling of the Antarctic moss Pohlia nutans under UV-B radiation was conducted by Illumina HiSeq2500 platform. Totally, 72,922 unigenes with N50 length of 1434 bp were generated. Differential expression analysis demonstrated that 581 unigenes were markedly up-regulated and 249 unigenes were significantly down-regulated. The gene clustering analysis showed that these differentially expressed genes (DEGs) includes several transcription factors, photolyases, antioxidant enzymes, and flavonoid biosynthesis-related genes. Further analyses suggested that the content of malondialdehyde (MDA), the activities of several antioxidant enzymes (i.e., catalase, peroxidase, and glutathione reductase) were significantly enhanced upon UV-B treatment. Furthermore, the content of flavonoids and the gene expression levels of their synthesis-related enzymes were also markedly increased when plants were exposed to UV-B light. Therefore, these results suggested that the pathways of antioxidant enzymes, flavonoid synthesis and photolyases were the main defense systems that contributed to the adaption of Pohlia nutans to the enhanced UV-B radiation in Antarctica.


Assuntos
Briófitas/genética , Briófitas/fisiologia , Perfilação da Expressão Gênica , Espécies Reativas de Oxigênio/metabolismo , Raios Ultravioleta , Regiões Antárticas , Antioxidantes/metabolismo , Vias Biossintéticas/efeitos da radiação , Briófitas/efeitos da radiação , Flavonoides/biossíntese , Regulação da Expressão Gênica de Plantas/efeitos da radiação , Anotação de Sequência Molecular , Filogenia , Análise de Sequência de RNA , Regulação para Cima/efeitos da radiação
4.
FEMS Microbiol Lett ; 365(23)2018 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-30346510

RESUMO

Pectinases are enzymes that catalyze pectin degradation. There is a global demand for pectinases because of their wide utility and catalytic efficiency. Optimization of the fermentation process to increase the pectolytic enzyme activity is generally practiced to lower process costs, but whether temperature influences the metabolome, enhancing pectinase activity, is not known. Here, we developed a metabolomics approach to explore it. The activity of P-DY2 pectinase produced by Bacillus licheniformis DY2 was higher in cells grown at 30°C than those grown at 37°C. Differential metabolome analysis revealed fluctuating tricarboxylic acid (TCA) cycle at 30°C. Consistently, the transcripts of TCA cycle genes and activities of pyruvate dehydrogenase and α-Ketoglutaric dehydrogenase were lower at 30°C than 37°C. Furthermore, inhibition of pyruvate dehydrogenase and succinate dehydrogenase enhanced the activity of P-DY2, supporting the conclusion that the inactivated pyruvate metabolism and TCA cycle were required for pectinase activity, and that P-DY2 was TCA cycle-independent. Collectively, these findings indicated that fermentation temperature affected P-DY2 activity by metabolic modulation, with an inactivated TCA cycle as a characteristic feature of high P-DY2 activity. More importantly, the present study highlights an approach of promoting pectinase activity through metabolic modulation by using metabolic pathway inhibitors.


Assuntos
Bacillus licheniformis/enzimologia , Bacillus licheniformis/efeitos da radiação , Vias Biossintéticas/efeitos da radiação , Poligalacturonase/biossíntese , Bacillus licheniformis/metabolismo , Ciclo do Ácido Cítrico/efeitos da radiação , Fermentação/efeitos da radiação , Metabolômica , Pectinas/metabolismo , Temperatura
5.
J Agric Food Chem ; 66(42): 10931-10942, 2018 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-30269498

RESUMO

The effect and mechanism of preharvest and postharvest ultraviolet (UV) irradiation on anthocyanin biosynthesis during blueberry development were investigated. The results showed that preharvest UV-B,C and postharvest UV-A,B,C irradiation significantly promoted anthocyanin biosynthesis and the transcripts of late biosynthetic genes (LBG) VcDFR, VcANS, VcUFGT, and VcMYB transcription factor as well as DFR and UFGT activities in anthocyanin pathway in a UV wavelength- and developmental stage-dependent manner. VcMYB expression was positively correlated with that of VcANS and VcUFGT and coincided with anthocyanin biosynthesis responding to the UV radiation. Sugar decreased during postharvest but increased during preharvest UV radiation in mature fruit. Our results indicate that UV-responsive production of anthocyanins is mainly caused by the activation of anthocyanin downstream pathway genes, which could be upregulated by VcMYB. Furthermore, different potential response mechanisms may exist between preharvest and postharvest UV radiation in blueberries, involving a systemic response in living plants and a nonsystemic response in postharvest fruit.


Assuntos
Antocianinas/biossíntese , Mirtilos Azuis (Planta)/química , Proteínas de Plantas/biossíntese , Antocianinas/metabolismo , Vias Biossintéticas/efeitos da radiação , Mirtilos Azuis (Planta)/metabolismo , Mirtilos Azuis (Planta)/efeitos da radiação , Frutas/química , Frutas/metabolismo , Frutas/efeitos da radiação , Regulação da Expressão Gênica de Plantas/efeitos da radiação , Cinética , Extratos Vegetais/análise , Extratos Vegetais/química , Proteínas de Plantas/metabolismo , Fatores de Transcrição/biossíntese , Fatores de Transcrição/metabolismo , Ativação Transcricional , Raios Ultravioleta
6.
Plant J ; 96(3): 503-517, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30044520

RESUMO

Damaging UVB radiation is a major abiotic stress facing land plants. In angiosperms the UV RESISTANCE LOCUS8 (UVR8) photoreceptor coordinates UVB responses, including inducing biosynthesis of protective flavonoids. We characterised the UVB responses of Marchantia polymorpha (marchantia), the model species for the liverwort group of basal plants. Physiological, chemical and transcriptomic analyses were conducted on wild-type marchantia exposed to three different UVB regimes. CRISPR/Cas9 was used to obtain plant lines with mutations for components of the UVB signal pathway or the flavonoid biosynthetic pathway, and transgenics overexpressing the marchantia UVR8 sequence were generated. The mutant and transgenic lines were analysed for changes in flavonoid content, their response to UVB exposure, and transcript abundance of a set of 48 genes that included components of the UVB response pathway characterised for angiosperms. The marchantia UVB response included many components in common with Arabidopsis, including production of UVB-absorbing flavonoids, the central activator role of ELONGATED HYPOCOTYL5 (HY5), and negative feedback regulation by REPRESSOR OF UV-B PHOTOMORPHOGENESIS1 (RUP1). Notable differences included the greater importance of CHALCONE ISOMERASE-LIKE (CHIL). Mutants disrupted in the response pathway (hy5) or flavonoid production (chalcone isomerase, chil) were more easily damaged by UVB. Mutants (rup1) or transgenics (35S:MpMYB14) with increased flavonoid content had increased UVB tolerance. The results suggest that UVR8-mediated flavonoid induction is a UVB tolerance character conserved across land plants and may have been an early adaptation to life on land.


Assuntos
Flavonoides/metabolismo , Magnoliopsida/fisiologia , Marchantia/fisiologia , Proteínas de Plantas/genética , Transdução de Sinais/efeitos da radiação , Vias Biossintéticas/efeitos da radiação , Perfilação da Expressão Gênica , Magnoliopsida/genética , Magnoliopsida/efeitos da radiação , Marchantia/genética , Marchantia/efeitos da radiação , Raios Ultravioleta
7.
World J Microbiol Biotechnol ; 34(7): 96, 2018 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-29916185

RESUMO

The unicellular green microalga Haematococcus pluvialis has the highest content of the natural antioxidant, astaxanthin. Previously, it was determined that astaxanthin accumulation in H. pluvialis could be induced by blue-wavelength irradiation; however, the molecular mechanism remains unknown. The present study aimed to compare the transcriptome of H. pluvialis, with respect to astaxanthin biosynthesis, under the monochromatic red (660 nm) or blue (450 nm) light-emitting diode (LED) irradiation. Among a total of 165,372 transcripts, we identified 67,703 unigenes, of which 2245 and 171 were identified as differentially expressed genes (DEGs) in response to blue and red irradiation, respectively. Interestingly, expressional changes of blue light receptor cryptochromes were detected in response to blue and/or red LED irradiation in H. pluvialis, which may directly and indirectly regulate astaxanthin biosynthesis. In accordance with this observation, expression of the BKT and CHY genes, which are part of the downstream section of the astaxanthin biosynthetic pathway, was significantly upregulated by blue LED irradiation compared with their expression under control white irradiation. Contrastingly, they were downregulated by red LED irradiation. Our transcriptome study provided molecular insights that highlighted the different of responses of H. pluvialis to red and blue irradiation, especially for astaxanthin biosynthesis.


Assuntos
Clorófitas/genética , Clorófitas/metabolismo , Clorófitas/efeitos da radiação , Regulação da Expressão Gênica de Plantas/efeitos da radiação , Luz , Transcriptoma , Vias Biossintéticas/genética , Vias Biossintéticas/efeitos da radiação , Divisão Celular/efeitos da radiação , Clorófitas/crescimento & desenvolvimento , Análise por Conglomerados , Cor , Perfilação da Expressão Gênica , Ontologia Genética , Genes de Plantas/genética , Genes de Plantas/efeitos da radiação , Microbiologia Industrial , Iluminação , Espécies Reativas de Oxigênio/metabolismo , Análise de Sequência de RNA , Regulação para Cima , Xantofilas/biossíntese , Xantofilas/genética
8.
Sci Rep ; 8(1): 277, 2018 01 10.
Artigo em Inglês | MEDLINE | ID: mdl-29321619

RESUMO

Land plants protect themselves from ultraviolet-B (UV-B) by accumulating UV-absorbing metabolites, which may also function as anti-insect toxins. Previous studies have shown that UV-B enhances the resistance of different plant species to pierce-sucking pests; however, whether and how UV-B influences plant defense against chewing caterpillars are not well understood. Here we show that UV-B treatment increased Spodoptera litura herbivory-induced jasmonic acid (JA) production in Arabidopsis and thereby Arabidopsis exhibited elevated resistance to S. litura. Using mutants impaired in the biosynthesis of JA and the defensive metabolites glucosinolates (GSs), we show that the UV-B-induced resistance to S. litura is dependent on the JA-regulated GSs and an unidentified anti-insect metabolite(s). Similarly, UV-B treatment also enhanced the levels of JA-isoleucine conjugate and defense-related secondary metabolites in tobacco, rice, and maize after these plants were treated with simulated herbivory of lepidopteran insects; consistently, these plants showed elevated resistance to insect larvae. Using transgenic plants impaired in JA biosynthesis or signaling, we further demonstrate that the UV-B-enhanced defense responses also require the JA pathway in tobacco and rice. Our findings reveal a likely conserved JA-dependent mechanism by which UV-B enhances plant defense against lepidopteran insects.


Assuntos
Vias Biossintéticas/efeitos da radiação , Ciclopentanos/metabolismo , Herbivoria , Lepidópteros , Oxilipinas/metabolismo , Plantas/metabolismo , Plantas/parasitologia , Plantas/efeitos da radiação , Raios Ultravioleta , Animais , Arabidopsis/genética , Arabidopsis/metabolismo , Arabidopsis/parasitologia , Arabidopsis/efeitos da radiação , Resistência à Doença , Oryza/genética , Oryza/metabolismo , Oryza/parasitologia , Oryza/efeitos da radiação , Reguladores de Crescimento de Planta/metabolismo , Plantas/genética , Metabolismo Secundário , Transdução de Sinais/efeitos da radiação
9.
Cancer Med ; 6(7): 1639-1651, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28608446

RESUMO

Here, we examined the potential of blocking the thymidine de novo synthesis pathways for sensitizing melanoma cells to the nucleoside salvage pathway targeting endogenous DNA irradiation. Expression of key nucleotide synthesis and proliferation enzymes thymidylate synthase (TS) and thymidine kinase 1 (TK1) was evaluated in differentiated (MITFhigh [microphthalmia-associated transcription factor] IGR1) and invasive (MITFmedium IGR37) melanoma cells. For inhibition of de novo pathways cells were incubated either with an irreversible TS inhibitor 5-fluoro-2'-deoxyuridine (FdUrd) or with a competitive dihydrofolate-reductase (DHFR) inhibitor methotrexate (MTX). Salvage pathway was addressed by irradiation-emitting thymidine analog [123/125 I]-5-iodo-4'-thio-2'-deoxyuridine (123/125 I-ITdU). The in vivo targeting efficiency was visualized by single-photon emission computed tomography. Pretreatment with FdUrd strongly increased the cellular uptake and the DNA incorporation of 125 I-ITdU into the mitotically active IGR37 cells. This effect was less pronounced in the differentiated IGR1 cells. In vivo, inhibition of TS led to a high and preferential accumulation of 123 I-ITdU in tumor tissue. This preclinical study presents profound rationale for development of therapeutic approach by highly efficient and selective radioactive targeting one of the crucial salvage pathways in melanomas.


Assuntos
Antineoplásicos/farmacologia , Vias Biossintéticas/efeitos dos fármacos , Melanoma/metabolismo , Timidina/biossíntese , Animais , Antineoplásicos/uso terapêutico , Biomarcadores , Vias Biossintéticas/efeitos da radiação , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Pontos de Checagem do Ciclo Celular/efeitos da radiação , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Glutationa/metabolismo , Humanos , Radioisótopos do Iodo , Melanoma/diagnóstico por imagem , Melanoma/tratamento farmacológico , Melanoma/patologia , Camundongos , Mitose/efeitos dos fármacos , Mitose/genética , Imagem Molecular , Terapia de Alvo Molecular , Nucleosídeos/metabolismo , Oxirredução , Radiação , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/efeitos da radiação
10.
Molecules ; 22(4)2017 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-28441769

RESUMO

Previously, we found that phenolic content and antioxidant capacity (AOX) in carrots increased with wounding intensity. It was also reported that UV radiation may trigger the phenylpropanoid metabolism in plant tissues. Here, we determined the combined effect of wounding intensity and UV radiation on phenolic compounds, AOX, and the phenylalanine ammonia-lyase (PAL) activity of carrots. Accordingly, phenolic content, AOX, and PAL activity increased in cut carrots with the duration of UVC radiation, whereas whole carrots showed no increase. Carrot pies showed a higher increase compared to slices and shreds. Phenolics, AOX, and PAL activity also increased in cut carrots exposed to UVA or UVB. The major phenolics were chlorogenic acid and its isomers, ferulic acid, and isocoumarin. The type of UV radiation affected phenolic profiles. Chlorogenic acid was induced by all UV radiations but mostly by UVB and UVC, ferulic acid was induced by all UV lights to comparable levels, while isocoumarin and 4,5-diCQA was induced mainly by UVB and UVC compared to UVA. In general, total phenolics correlated linearly with AOX for all treatments. A reactive oxygen species (ROS) mediated hypothetical mechanism explaining the synergistic effect of wounding and different UV radiation stresses on phenolics accumulation in plants is herein proposed.


Assuntos
Antioxidantes/metabolismo , Daucus carota/metabolismo , Vias Biossintéticas/efeitos da radiação , Ácido Clorogênico/metabolismo , Culinária , Ácidos Cumáricos/metabolismo , Daucus carota/efeitos da radiação , Isocumarinas/metabolismo , Ácido Quínico/análogos & derivados , Ácido Quínico/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Raios Ultravioleta
11.
Physiol Plant ; 159(4): 381-400, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-27580641

RESUMO

Rose-scented geranium (Pelargonium spp.) is one of the most important aromatic plants and is well known for its diverse perfumery uses. Its economic importance is due to presence of fragrance rich essential oil in its foliage. The essential oil is a mixture of various volatile phytochemicals which are mainly terpenes (isoprenoids) in nature. In this study, on the geranium foliage genes related to isoprenoid biosynthesis (DXS, DXR and HMGR) were isolated, cloned and confirmed by sequencing. Further, the first gene of 2-C-methyl-d-erythritol-4-phosphate (MEP) pathway, 1-deoxy-d-xylulose-5-phosphate synthase (GrDXS), was made full length by using rapid amplification of cDNA ends strategy. GrDXS contained a 2157 bp open reading frame that encoded a polypeptide of 792 amino acids having calculated molecular weight 77.5 kDa. This study is first report on heterologous expression and kinetic characterization of any gene from this economically important plant. Expression analysis of these genes was performed in different tissues as well as at different developmental stages of leaves. In response to external elicitors, such as methyl jasmonate, salicylic acid, light and wounding, all the three genes showed differential expression profiles. Further GrDXS was over expressed in the homologous (rose-scented geranium) as well as in heterologous (Withania somnifera) plant systems through genetic transformation approach. The over-expression of GrDXS led to enhanced secondary metabolites production (i.e. essential oil in rose-scented geranium and withanolides in W. somnifera). To the best of our knowledge, this is the first report showing the expression profile of the three genes related to isoprenoid biosynthesis pathways operated in rose-scented geranium as well as functional characterization study of any gene from rose-scented geranium through a genetic transformation system.


Assuntos
Vias Biossintéticas/genética , Butadienos/metabolismo , Genes de Plantas , Geranium/genética , Hemiterpenos/metabolismo , Pentanos/metabolismo , Plastídeos/metabolismo , Metabolismo Secundário/genética , Terpenos/metabolismo , Withania/genética , Acetatos/farmacologia , Sequência de Bases , Biocatálise/efeitos dos fármacos , Vias Biossintéticas/efeitos dos fármacos , Vias Biossintéticas/efeitos da radiação , Clonagem Molecular , Biologia Computacional , Ciclopentanos/farmacologia , Evolução Molecular , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Regulação da Expressão Gênica de Plantas/efeitos da radiação , Geranium/efeitos dos fármacos , Geranium/efeitos da radiação , Luz , Oxilipinas/farmacologia , Filogenia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plastídeos/efeitos dos fármacos , Plastídeos/efeitos da radiação , Proteínas Recombinantes/metabolismo , Metabolismo Secundário/efeitos dos fármacos , Metabolismo Secundário/efeitos da radiação , Alinhamento de Sequência , Análise de Sequência de DNA , Homologia Estrutural de Proteína , Withania/efeitos dos fármacos , Withania/efeitos da radiação
12.
Plant Cell Physiol ; 57(11): 2269-2282, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27519311

RESUMO

The carotenoid composition of the filamentous heterocystous N2-fixing cyanobacterium Calothrix sp. 336/3 was investigated under three conditions: in full medium (non-diazotrophic growth); in the absence of combined nitrogen (diazotrophic growth); and after long-term H2 photoproduction (diazotrophic medium and absence of nitrogen in the atmosphere). Anabaena sp. PCC 7120 and its ΔhupL mutant with disrupted uptake hydrogenase were used as reference strains. Analysis of identified carotenoids and enzymes involved in carotenogenesis showed the presence of three distinct biosynthetic pathways in Calothrix sp. 336/3. The first one is directed towards biosynthesis of myxoxanthophylls, such as myxol 2'-methylpentoside and 2-hydroxymyxol 2'-methylpentoside. The second pathway results in production of hydroxylated carotenoids, such as zeaxanthin, caloxanthin and nostoxanthin, and the last pathway is responsible for biosynthesis of echinenone and hydroxylated forms of ketocarotenoids, such as 3'-hydroxyechinenone and adonixanthin. We found that carotenogenesis in filamentous heterocystous cyanobacteria varies depending on the nitrogen status of the cultures, with significant accumulation of echinenone during diazotrophic growth at the expense of ß-carotene. Under the severe N deficiency and high CO2 supply, which leads to efficient H2 photoproduction, cyanobacteria degrade echinenone and ß-carotene, and accumulate glycosylated and hydroxylated carotenoids, such as myxol (or ketomyxol) 2'-methylpentosides, 3'-hydroxyechinenone and zeaxanthin. We suggest that the stability of the photosynthetic apparatus in Calothrix sp. 336/3 cells under N deficiency and high carbon conditions, which also appeared as the partial recovery of the pigment composition by the end of the long-term (∼1 month) H2 photoproduction process, might be mediated by a high content of hydroxycarotenoids.


Assuntos
Vias Biossintéticas/efeitos da radiação , Carotenoides/biossíntese , Cianobactérias/crescimento & desenvolvimento , Cianobactérias/efeitos da radiação , Hidrogênio/metabolismo , Luz , Fixação de Nitrogênio/efeitos da radiação , Vias Biossintéticas/genética , Cromatografia Líquida de Alta Pressão , Meios de Cultura , Cianobactérias/genética , Cianobactérias/metabolismo , Genes Bacterianos , Pigmentos Biológicos/metabolismo , Análise Espectral , Fatores de Tempo
13.
Food Chem ; 209: 99-103, 2016 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-27173540

RESUMO

Glucosinolates, found principally in the plant order Brassicales, are modulated by different post-harvest processing operations. Among these, ionizing radiation, a non-thermal process, has gained considerable interest for ensuring food security and safety. In gamma-irradiated cabbage, enhanced sinigrin, a major glucosinolate, has been reported. However, the molecular basis of such a radiation induced effect is not known. Herein, the effect of radiation processing on the expression of glucosinolate biosynthetic genes was investigated. RT-PCR based expression analysis of seven glucosinolate biosynthetic pathway genes (MYB28, CYP79F1, CYP83A1, SUR1, UGT74B1, SOT18 and TGG1) showed that CYP83A1, MYB28, UGT74B1, CYP79F1 and SUR1 were up-regulated in irradiated cabbage. The content of jasmonates, signalling molecules involved in glucosinolate induction was, however, unaffected in irradiated cabbage suggesting their non-involvement in glucosinolate induction during radiation processing. This is the first report on the effect of gamma irradiation on the expression of glucosinolate biosynthetic genes in vegetables.


Assuntos
Vias Biossintéticas/efeitos da radiação , Brassica/genética , Raios gama , Regulação da Expressão Gênica de Plantas/efeitos da radiação , Glucosinolatos/metabolismo , Proteínas de Plantas/genética , Brassica/metabolismo , Brassica/efeitos da radiação , Glucosinolatos/análise , Reação em Cadeia da Polimerase em Tempo Real
14.
Plant Physiol Biochem ; 107: 1-8, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27235646

RESUMO

Floral volatile phenylpropanoids and benzenoids (VPBs) play important ecological functions and have potential economic applications. Little is known about how multi-factors in integration regulate the formation and emission of floral VPBs. In the present study, we investigated effects of multi factors including endogenous circadian clock, light, and temperature on the formation and emission of VPBs, which are major volatiles in flowers of Petunia× hybrida cv. 'Mitchell Diploid'. Endogenous circadian clock was proposed as the most important factor regulating rhythmic emission of VPBs and expressions of structural genes involved in the upstream biosynthetic pathway of VPBs, but did not affect expression levels of structural genes involved in the downstream pathway and VPBs-related regulators. In contrast to light, temperature was a more constant factor affecting emission of VPBs. VPBs emission could be inhibited within a short time by increasing temperature. The information will contribute to our understanding of emission mechanism of floral volatiles.


Assuntos
Benzeno/metabolismo , Vias Biossintéticas , Relógios Circadianos/efeitos da radiação , Flores/metabolismo , Luz , Petunia/metabolismo , Propanóis/metabolismo , Temperatura , Compostos Orgânicos Voláteis/metabolismo , Vias Biossintéticas/genética , Vias Biossintéticas/efeitos da radiação , Cruzamentos Genéticos , Flores/genética , Regulação da Expressão Gênica de Plantas/efeitos da radiação , Modelos Biológicos , Petunia/genética , Petunia/efeitos da radiação
15.
BMC Plant Biol ; 16: 95, 2016 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-27098458

RESUMO

BACKGROUND: Carotenoids are important pigments and precursors for central signaling molecules associated in fruit development and ripening. Carotenoid metabolism has been studied especially in the climacteric tomato fruit but the content of carotenoids and the regulation of their metabolism have been shown to be highly variable between fruit species. Non-climacteric berries of the genus Vaccinium are among the best natural sources of health-beneficial flavonoids but not studied previously for carotenoid biosynthesis. RESULTS: In this study, carotenoid biosynthetic genes, PSY, PDS, ZDS, CRTISO, LCYB, LCYE, BCH and CYP450-BCH, as well as a carotenoid cleavage dioxygenase CCD1 were identified from bilberry (V. myrtillus L.) fruit and their expression was studied along with carotenoid composition during fruit development under different photoperiod and light quality conditions. Bilberry was found to be a good source of carotenoids among fruits and berries. The most abundant carotenoids throughout the berry development were lutein and ß-carotene, which were accompanied by lower amounts of 9Z-ß-carotene, violaxanthin, neoxanthin, zeaxanthin, antheraxanthin and ß-cryptoxanthin. The expression patterns of the biosynthetic genes in ripening fruits indicated a metabolic flux towards ß-branch of the carotenoid pathway. However, the carotenoid levels decreased in both the ß-branch and ε,ß-branch towards bilberry fruit ripening along with increased VmCCD1 expression, similarly to VmNCED1, indicating enzymatic carotenoid cleavage and degradation. Intense white light conditions increased the expression of the carotenoid biosynthetic genes but also the expression of the cleavage genes VmCCD1 and VmNCED1, especially in unripe fruits. Instead, mature bilberry fruits responded specifically to red/far-red light wavelengths by inducing the expression of both the carotenoid biosynthetic and the cleavage genes indicating tissue and developmental stage specific regulation of apocarotenoid formation by light quality. CONCLUSIONS: This is the first report of carotenoid biosynthesis in Vaccinium berries. Our results indicate that both transcriptional regulation of the key biosynthetic genes and the enzymatic degradation of the produced carotenoids to apocarotenoids have significant roles in the determination of the carotenoid content and have overall effect on the metabolism during the bilberry fruit ripening.


Assuntos
Vias Biossintéticas/efeitos da radiação , Carotenoides/metabolismo , Frutas/metabolismo , Luz , Vaccinium myrtillus/metabolismo , Vias Biossintéticas/genética , Cromatografia Líquida de Alta Pressão , Dioxigenases/genética , Dioxigenases/metabolismo , Frutas/genética , Frutas/crescimento & desenvolvimento , Regulação da Expressão Gênica no Desenvolvimento/efeitos da radiação , Regulação da Expressão Gênica de Plantas/efeitos da radiação , Fotoperíodo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Vaccinium myrtillus/genética , Vaccinium myrtillus/crescimento & desenvolvimento
16.
J Exp Bot ; 67(8): 2495-506, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26969746

RESUMO

Plant chloroplasts are light-driven cell factories that have great potential to act as a chassis for metabolic engineering applications. Using plant chloroplasts, we demonstrate how photosynthetic reducing power can drive a metabolic pathway to synthesise a bio-active natural product. For this purpose, we stably engineered the dhurrin pathway from Sorghum bicolor into the chloroplasts of Nicotiana tabacum (tobacco). Dhurrin is a cyanogenic glucoside and its synthesis from the amino acid tyrosine is catalysed by two membrane-bound cytochrome P450 enzymes (CYP79A1 and CYP71E1) and a soluble glucosyltransferase (UGT85B1), and is dependent on electron transfer from a P450 oxidoreductase. The entire pathway was introduced into the chloroplast by integrating CYP79A1, CYP71E1, and UGT85B1 into a neutral site of the N. tabacum chloroplast genome. The two P450s and the UGT85B1 were functional when expressed in the chloroplasts and converted endogenous tyrosine into dhurrin using electrons derived directly from the photosynthetic electron transport chain, without the need for the presence of an NADPH-dependent P450 oxidoreductase. The dhurrin produced in the engineered plants amounted to 0.1-0.2% of leaf dry weight compared to 6% in sorghum. The results obtained pave the way for plant P450s involved in the synthesis of economically important compounds to be engineered into the thylakoid membrane of chloroplasts, and demonstrate that their full catalytic cycle can be driven directly by photosynthesis-derived electrons.


Assuntos
Vias Biossintéticas , Cloroplastos/metabolismo , Cloroplastos/efeitos da radiação , Sistema Enzimático do Citocromo P-450/metabolismo , Luz , Nitrilos/metabolismo , Sorghum/enzimologia , Tabaco/genética , Biomassa , Vias Biossintéticas/genética , Vias Biossintéticas/efeitos da radiação , Cloroplastos/ultraestrutura , Cromatografia Líquida , Regulação Enzimológica da Expressão Gênica/efeitos da radiação , Genoma de Cloroplastos , Genoma de Planta , Glucosídeos/metabolismo , Espectrometria de Massas , Óperon/genética , Fenótipo , Fotossíntese/efeitos da radiação , Plantas Geneticamente Modificadas , Subunidades Proteicas/metabolismo , Transformação Genética/efeitos da radiação
17.
Redox Biol ; 8: 79-90, 2016 08.
Artigo em Inglês | MEDLINE | ID: mdl-26765101

RESUMO

Dietary phenolics may play a protective role in UV-mediated skin pigmentation through their antioxidant and UV-absorbing actions. In this study, we investigated whether genetic silencing of Nrf2, regulating the transcription of antioxidant genes, affected melanogenesis in primary human epidermal melanocytes (HEMn) and B16F10 melanoma cells subjected to UVA (8J/cm(2)) exposure. Then, we explored the antimelanogenic actions of phenolics; caffeic acid (CA) and ferulic acid (FA) providing partial UVA protection; quercetin (QU) and rutin (RU) providing strong UVA protection and; avobenzone (AV), an efficient UVA filter, in association with modulation of Nrf2-mediated antioxidant defenses in response to UVA insults in B16F10 cells. Upon oxidative insults, Nrf2 silencing promoted melanogenesis in both HEMn and B16F10 cells irradiated with UVA. Stimulation of melanogenesis by UVA correlated with increased ROS and oxidative DNA damage (8-OHdG), GSH depletion as well as a transient downregulation of Nrf2 nuclear translocation and of Nrf2-ARE signaling in B16F10 cells. All test compounds exerted antimelanogenic effects with respect to their abilities to reverse UVA-mediated oxidative damage as well as downregulation of Nrf2 activity and its target antioxidants (GCLC, GST and NQO1) in B16F10 cells. In conclusion, defective Nrf2 may promote melanogenesis under UVA irradiation through oxidative stress mechanisms. Compounds with antioxidant and/or UVA absorption properties could protect against UVA-induced melanogenesis through indirect regulatory effect on Nrf2-ARE pathway.


Assuntos
Antioxidantes/farmacologia , Suplementos Nutricionais , Melaninas/biossíntese , Fator 2 Relacionado a NF-E2/metabolismo , Fenóis/farmacologia , Substâncias Protetoras/farmacologia , Raios Ultravioleta , Animais , Elementos de Resposta Antioxidante , Vias Biossintéticas/efeitos dos fármacos , Vias Biossintéticas/efeitos da radiação , Dano ao DNA/efeitos dos fármacos , Desoxiguanosina/análogos & derivados , Desoxiguanosina/farmacologia , Técnicas de Silenciamento de Genes , Glutationa/metabolismo , Humanos , Melanócitos/efeitos dos fármacos , Melanócitos/metabolismo , Melanócitos/efeitos da radiação , Melanoma/genética , Melanoma/metabolismo , Melanoma Experimental , Camundongos , Monofenol Mono-Oxigenase/metabolismo , Fator 2 Relacionado a NF-E2/genética , Interferência de RNA , Espécies Reativas de Oxigênio/metabolismo , Transcrição Genética
18.
Chembiochem ; 17(4): 296-9, 2016 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-26677142

RESUMO

Controlling cellular functions by light allows simple triggering of biological processes in a non-invasive fashion with high spatiotemporal resolution. In this context, light-regulated gene expression has enormous potential for achieving optogenetic control over almost any cellular process. Here, we report on two novel one-step cleavable photocaged arabinose compounds, which were applied as light-sensitive inducers of transcription in bacteria. Exposure of caged arabinose to UV-A light resulted in rapid activation of protein production, as demonstrated for GFP and the complete violacein biosynthetic pathway. Moreover, single-cell analysis revealed that intrinsic heterogeneity of arabinose-mediated induction of gene expression was overcome when using photocaged arabinose. We have thus established a novel phototrigger for synthetic bio(techno)logy applications that enables precise and homogeneous control of bacterial target gene expression.


Assuntos
Arabinose/metabolismo , Chromobacterium/genética , Escherichia coli/genética , Regulação Bacteriana da Expressão Gênica , Optogenética/métodos , Vias Biossintéticas/efeitos da radiação , Chromobacterium/metabolismo , Chromobacterium/efeitos da radiação , Escherichia coli/metabolismo , Escherichia coli/efeitos da radiação , Regulação Bacteriana da Expressão Gênica/efeitos da radiação , Indóis/metabolismo , Família Multigênica/efeitos da radiação , Análise de Célula Única , Raios Ultravioleta
19.
PLoS One ; 10(12): e0145242, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26670930

RESUMO

Shoot regeneration in calli derived from immature barley embryos is regulated by light conditions during the callus-induction period. Barley cultivars Kanto Nijo-5 (KN5) and K-3 (K3) showed lower efficiency of shoot regeneration in a 16-h photoperiod during callus-induction than those in continuous darkness, whereas shoot regeneration was enhanced in cultures under a 16-h photoperiod in Golden Promise (GP) and Lenins (LN). These cultivars were classified as photo-inhibition type (KN5 and K3) or photo-induction type (GP and LN) according to their response to light. Contents of endogenous plant hormones were determined in calli cultured under a 16-h photoperiod and continuous darkness. In photo-inhibition type, higher accumulation of abscisic acid (ABA) was detected in calli cultured under a 16-h photoperiod, whereas calli showed lower levels of endogenous ABA in continuous darkness. However, cultivars of photo-induction type showed lower levels of ABA in calli cultured under both light conditions, similarly to photo-inhibition type in continuous darkness. Exogenous ABA inhibited the callus growth and shoot regeneration independent of light conditions in all cultivars. In photo-inhibition type, lower levels of endogenous ABA induced by ABA biosynthesis inhibitor, fluridone, reduced the photo-inhibition of shoot regeneration. Expression of ABA biosynthesis gene, HvNCED1, in calli was regulated by the light conditions. Higher expression was observed in calli cultured under a 16-h photoperiod. These results indicate that ABA biosynthesis could be activated through the higher expression of HvNCED1 in a 16-h photoperiod and that the higher accumulations of ABA inhibit shoot regeneration in the photo-inhibition type cultivars.


Assuntos
Ácido Abscísico/farmacologia , Hordeum/embriologia , Luz , Brotos de Planta/fisiologia , Regeneração/efeitos dos fármacos , Sementes/fisiologia , Vias Biossintéticas/efeitos dos fármacos , Vias Biossintéticas/genética , Vias Biossintéticas/efeitos da radiação , Genes de Plantas , Hordeum/efeitos dos fármacos , Hordeum/genética , Hordeum/efeitos da radiação , Reguladores de Crescimento de Planta/farmacologia , Brotos de Planta/efeitos dos fármacos , Brotos de Planta/efeitos da radiação , Piridonas/farmacologia , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Regeneração/efeitos da radiação , Sementes/efeitos dos fármacos , Sementes/efeitos da radiação , Técnicas de Cultura de Tecidos
20.
Plant Physiol Biochem ; 97: 304-12, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26512970

RESUMO

Kidney bean (Phaseolus vulgaris L.) is an important dietary legume crop cultivated and consumed worldwide. A purple cultivar (Zi Bawang) and a green cultivar (Chun Qiu), the main difference of which is in the pod skin color, were selected for the study. Malvidin 3, 5-diglucoside is identified as the major anthocyanin in the pod skin of Zi Bawang by HPLC-ESI-MS/MS. Three regulatory genes PvMYB1, PvMYB2, PvTT8-1 and most structural genes are dramatically up-regulated in purple pod skin compared to those in other materials. Significantly decreased expression levels of all regulatory genes and most biosynthetic genes are also detected in the purple skin of pods covered with bags compared to non-covered ones. All the results suggest that PvMYB1, PvMYB2 and PvTT8-1 might play a critical role in transcriptional activation of most anthocyanin biosynthetic genes in purple kidney bean pod.


Assuntos
Antocianinas/metabolismo , Vias Biossintéticas/genética , Regulação da Expressão Gênica de Plantas , Genes de Plantas , Phaseolus/genética , Antocianinas/química , Vias Biossintéticas/efeitos da radiação , Cromatografia Líquida de Alta Pressão , Regulação da Expressão Gênica de Plantas/efeitos da radiação , Luz , Fenótipo , Espectrometria de Massas por Ionização por Electrospray
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA