Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 7.237
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Food Chem ; 307: 125525, 2020 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-31639577

RESUMO

This study investigated effects of different concentrations of methyl jasmonate (MeJA) on carotenoids accumulation, radical scavenging activity and proline content in germinated maize kernels. MeJA treatment promoted carotenoids accumulation, radical scavenging activity and proline accumulation, while salicyl hydroxamic acid (SHAM) reduced carotenoids accumulation. There was a significant increase of 42.5% in lutein content when treated with 0.5 µM MeJA. Furthermore, the transcriptional expression of seven carotenogenic genes were explored by MeJA and SHAM. The results showed that 0.5 µM MeJA significantly increased the gene expression levels of PSY, PDS, ZDS, LCYB, LCYE, BCH1, CYP97C, and their transcript levels, which were strongly associated with carotenoids content. Treatment of MeJA affected the carotenoids biosynthesis gene and led to the accumulation of carotenoids. These new findings would help to develop innovative approach for enrichment of lutein in germinated maize kernels for further development of functional food materials.


Assuntos
Acetatos/farmacologia , Carotenoides/metabolismo , Ciclopentanos/farmacologia , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Oxilipinas/farmacologia , Zea mays/crescimento & desenvolvimento , Carotenoides/análise , Cromatografia Líquida de Alta Pressão , Depuradores de Radicais Livres/química , Germinação , Luteína/análise , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Prolina/análise , Zea mays/metabolismo
2.
Food Chem ; 308: 125707, 2020 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-31669943

RESUMO

The ripening of the apple (Malus × domestica Borkh.) fruit is regulated by the phytohormone ethylene, where degreening is an important physiological metabolism caused by chlorophyll (Chl) degradation. However, to date, research on how ethylene affects the Chl degradation pathway of apple peel during ripening remains scarce. In this study, the effects of ethylene on the expression of Chl catabolic genes (CCGs) of apple peel during ripening were studied by treating harvested commercial mature apples with 0.5 µL L-1 1-methylcyclopropene (1-MCP). The results showed that 1-MCP treatment led to a delayed climacteric peak of respiration and ethylene production, exhibiting higher Chl content and hue angle (H˚) compared to untreated fruit during ripening. Lower quantities of pheophorbide a oxygenase (PAO), pheophytinase (PPH) and red Chl catabolite reductase (RCCR) were also observed in peel tissues under 1-MCP treatment during ripening. Further study with quantitative real-time polymerase chain reaction (qPCR) revealed that the expression of CCGs, except for MdNYE1a, increased atdifferentdegrees upon ripening. Meanwhile, the apples treated with 1-MCP presented a downregulated expression of MdRCCR2, MdNYC1, MdNYC3 and MdNOL2 and a fluctuating expression of MdNYE1a, MdPPH1, MdPAO6, MdPAO8 and MdHCAR compared with the controls during ripening. Our results indicated the regulatory role of ethylene in the Chl degradation pathway of apple peel during ripening.


Assuntos
Clorofila/metabolismo , Ciclopropanos/farmacologia , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Malus/metabolismo , Reguladores de Crescimento de Planta/farmacologia , Etilenos/metabolismo , Armazenamento de Alimentos , Frutas/efeitos dos fármacos , Frutas/metabolismo , Malus/efeitos dos fármacos , Proteínas de Plantas/metabolismo
3.
DNA Cell Biol ; 38(11): 1278-1291, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31584843

RESUMO

The plants being sessile cannot escape from the adverse environmental stresses, hence get negatively affected in terms of their growth and yield. Transcriptional control simultaneously regulate different cellular processes, minimizing the deleterious effects of these stresses. The salicylic acid (SA)-inducible WRKY family of transcription factors auto or crossregulate the stress signaling in response to abiotic and biotic stresses, facilitating enhanced stress tolerance. In this study, we characterized the group III WRKY gene, JcWRKY2 from ecological and economical valued shrub Jatropha curcas. The JcWRKY2 tobacco transgenics showed improved physiological growth parameters, elevated chlorophyll content, improved antioxidative activities, and increased endogenous SA with both salt and SA stress. Interestingly, the pretreatment with SA and hydrogen peroxide facilitated improved germination of transgenic seeds with salinity stress. The transgenics showed differential regulation of antioxidative enzymes, calcium/calmodulin, dehydrins, and phospholipase genes with salt and SA stress. The increased SA content in transgenics on stress treatments, enhanced the antioxidant capacity leading to reduced susceptibility to stresses. Thus, JcWRKY2 transgenics participate in SA-mediated, improved antioxidative status during salinity stress with reduced reactive oxygen species damage.


Assuntos
Jatropha/genética , Estresse Salino/genética , Tolerância ao Sal/genética , Tabaco/genética , Fatores de Transcrição/fisiologia , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Germinação/efeitos dos fármacos , Germinação/genética , Estresse Oxidativo/efeitos dos fármacos , Estresse Oxidativo/genética , Plantas Geneticamente Modificadas , Salinidade , Cloreto de Sódio/farmacologia , Estresse Fisiológico/genética , Tabaco/efeitos dos fármacos , Tabaco/crescimento & desenvolvimento , Fatores de Transcrição/genética
4.
Plant Mol Biol ; 101(4-5): 507-516, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31617145

RESUMO

KEY MESSAGE: MMDH2 gene negatively regulates Cd tolerance by modulating reactive oxygen species (ROS) levels and the ROS-mediated signaling, thus, affecting the expression of PDR8. The molecular mechanism by which plants respond to stress caused by cadmium (Cd), one of the most toxic heavy metals to plants, is not well understood. Here, we show that MMDH2, a gene encoding mitochondrial malate dehydrogenase, is involved in Cd stress tolerance in Arabidopsis. The expression of MMDH2 was repressed by Cd stress. The mmdh2 knockdown mutants showed enhanced Cd tolerance, while the MMDH2-overexpressing lines were sensitive to Cd. Under normal and Cd stress conditions, lower H2O2 levels were detected in mmdh2 mutant plants than in wild-type plants. In contrast, higher H2O2 levels were found in MMDH2-overexpressing lines, and they were negatively correlated with malondialdehyde levels. In addition, the expression of the PDR8, a gene encoding a Cd efflux pump, increased and decreased in the mmdh2 mutant and MMDH2-overexpressing lines, in association with lower and higher Cd concentrations, respectively. These results suggest that the MMDH2 gene negatively regulates Cd tolerance by modulating reactive oxygen species (ROS) levels and the ROS-mediated signaling, thus, affecting the expression of PDR8.


Assuntos
Transportadores de Cassetes de Ligação de ATP/metabolismo , Proteínas de Arabidopsis/metabolismo , Arabidopsis/genética , Cádmio/toxicidade , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Transportadores de Cassetes de Ligação de ATP/genética , Sequência de Aminoácidos , Arabidopsis/fisiologia , Proteínas de Arabidopsis/genética , Cádmio/metabolismo , Técnicas de Silenciamento de Genes , Peróxido de Hidrogênio/metabolismo , Modelos Biológicos , Espécies Reativas de Oxigênio/metabolismo , Alinhamento de Sequência , Estresse Fisiológico
5.
Dokl Biochem Biophys ; 487(1): 264-268, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31559594

RESUMO

We studied the effect of zinc excess (1000 µM) and low positive temperature (4°C) on the IRT1 gene expression in barley roots and leaves. Exposure at each of the stress factors separately induced an increase in the content of the HvIRT1 gene transcripts, which was more pronounced in leaves. At the same time, the growth of seedlings continued. Under the combined action of the stress factors in the first 3 days, the amount of mRNA also increased, but after 7 days of exposure it significantly declined, which correlated with the complete inhibition of seedling growth. It is assumed that the seedling growth inhibition under the combined effect of zinc excess and low temperature is associated with a decrease in the transcriptional activity of the HvIRT1 gene, due to the deficiency in a number of trace elements under these conditions.


Assuntos
Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Hordeum/genética , Folhas de Planta/efeitos dos fármacos , Proteínas de Plantas/genética , Raízes de Plantas/efeitos dos fármacos , Temperatura Ambiente , Zinco/farmacologia , Relação Dose-Resposta a Droga , Hordeum/efeitos dos fármacos , Folhas de Planta/metabolismo , Raízes de Plantas/metabolismo
6.
Chemosphere ; 235: 1030-1040, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31561292

RESUMO

Organic pesticides are one of the main environmental pollutants, and how to reduce their environmental risks is an important issue. In this contribution, we disclose the molecular basis for the resistance of American sloughgrass to aryloxyphenoxypropionic acid pesticides using site-directed mutagenesis and molecular modeling and then construct an effective screening model. The results indicated that the target-site mutation (Trp-1999-Leu) in acetyl-coenzyme A carboxylase (ACCase) can affect the effectiveness of the pesticides (clodinafop, fenoxaprop, cyhalofop, and metamifop), and the plant resistance to fenoxaprop, clodinafop, cyhalofop, and metamifop was found to be 564, 19.5, 10, and 0.19 times, respectively. The established computational models (i.e. wild-type/mutant ACCase models) could be used for rational screening and evaluation of the resistance to pesticides. The resistance induced by target gene mutation can markedly reduce the bioreactivity of the ACCase-clodinafop/fenoxaprop adducts, and the magnitudes are 10 and 102, respectively. Such event will seriously aggravate environmental pollution. However, the biological issue has no distinct effect on cyhalofop (RI=10), and meanwhile it may markedly increase the bioefficacy of metamifop (RI=0.19). We could selectively adopt the two chemicals so as to decrease the residual pesticides in the environment. Significantly, research findings from the computational screening models were found to be negatively correlated with the resistance level derived from the bioassay testing, suggesting that the screening models can be used to guide the usage of pesticides. Obviously, this story may shed novel insight on the reduction of environmental risks of pesticides and other organic pollutants.


Assuntos
Acetil-CoA Carboxilase/antagonistas & inibidores , Biologia Computacional/métodos , Resistência a Herbicidas/genética , Praguicidas/toxicidade , Proteínas de Plantas/antagonistas & inibidores , Poaceae/crescimento & desenvolvimento , Acetil-CoA Carboxilase/genética , Acetil-CoA Carboxilase/metabolismo , Anilidas/toxicidade , Benzoxazóis/toxicidade , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Modelos Moleculares , Simulação de Acoplamento Molecular , Mutagênese Sítio-Dirigida , Mutação , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Poaceae/efeitos dos fármacos , Poaceae/enzimologia , Propionatos/toxicidade , Conformação Proteica , Piridinas/toxicidade , Estados Unidos
7.
Plant Physiol Biochem ; 142: 384-394, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31401434

RESUMO

Superoxide dismutases (SODs) play a pivotal role in improving abiotic stress tolerance in plant cells. A novel manganese superoxide dismutase gene, denoted as TmMnSOD, was identified from Triticum monococcum. The encoded protein displayed high sequence identity with MnSOD family members and was highly homologous to TdMnSOD from durum wheat. Furthermore, the 3D structure analysis revealed that TmMnSOD displayed homotetramer subunit organization, incorporating four Mn2+ ions. Notably, TmMnSOD structure contains predominantly alpha helices with three beta sheets. On the other hand, under stress conditions, TmMnSOD transcript level was significantly up-regulated by salt, oxidative and heavy metal stresses. At the functional level, TmMnSOD imparts tolerance of yeast and E. coli cells under diverse stresses. Promoter analysis of TmMnSOD gene showed the presence of a great number of salt and pathogen-responsive cis-regulatory elements, highlighting the interest of this gene in breeding programs towards improved tolerance to salt stress in wheat.


Assuntos
Metais Pesados/toxicidade , Superóxido Dismutase/metabolismo , Triticum/enzimologia , Clonagem Molecular , Diploide , Escherichia coli/enzimologia , Escherichia coli/metabolismo , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Microrganismos Geneticamente Modificados , Estresse Oxidativo , Filogenia , Reação em Cadeia da Polimerase em Tempo Real , Saccharomyces cerevisiae/enzimologia , Saccharomyces cerevisiae/metabolismo , Estresse Salino , Estresse Fisiológico , Superóxido Dismutase/química , Superóxido Dismutase/genética , Superóxido Dismutase/fisiologia , Triticum/genética , Triticum/metabolismo , Triticum/fisiologia
8.
Ecotoxicol Environ Saf ; 183: 109549, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31408818

RESUMO

Paspalum distichum L. was tested to evaluate its ability to phytoremediate mercury (Hg) contaminated soil over a 60-d period by analysis of the total Hg concentrations in roots and leaves. Hg concentration in Hg-contamination soil decreased by 70.0 µg g-1 after 60 day of grass cultivation and Hg was readily taken up by the roots (4.51 ±â€¯1.90 µg g-1) rather than the leaves (0.35 ±â€¯0.02 µg g-1). In addition, a comparative proteomic study was performed to unravel the protein expression involved in the Hg stress response in P. distichum L. A total of 49 proteins were classified as differentially proteins in the roots by the 'top three' proteomic analysis, of which 32 were up-regulated and 17 down-regulated in response to Hg stress. These changed proteins were classified by gene ontology analysis into five complex molecular functions involving photosynthesis and energy metabolism (31%), oxidative stress (14%), protein folding (16%), sulfur compound metabolism (10%), metal binding, and ion transport (29%). Moreover, the protein expression patterns were consistent with the metabolism pathway results. Overall, the results contribute to our understanding of the molecular mechanisms of the Hg response in P. distichum and we propose a theoretical basis for the phytoremediation of Hg-contaminated soils.


Assuntos
Mercúrio/toxicidade , Estresse Oxidativo/efeitos dos fármacos , Paspalum/efeitos dos fármacos , Proteínas de Plantas/metabolismo , Poluentes do Solo/toxicidade , Biodegradação Ambiental , Regulação para Baixo , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Mercúrio/metabolismo , Estresse Oxidativo/genética , Paspalum/genética , Paspalum/metabolismo , Fotossíntese/efeitos dos fármacos , Fotossíntese/genética , Folhas de Planta/metabolismo , Proteínas de Plantas/genética , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/metabolismo , Proteômica , Poluentes do Solo/metabolismo , Regulação para Cima
9.
Ecotoxicol Environ Saf ; 183: 109516, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31394375

RESUMO

The triclosan (TCS) is one of the most commonly detected organic pollutants in the sewage sludge. TCS could induce phytotoxicity in plants. Salicylic acid (SA) is a phenolic compound capable of enhancing plant growth and development. It is well documented that abiotic stress tolerance could be enhanced by exogenous application of SA. However, the regulatory mechanisms for functions of endogenous SA in plants' responses to xenobiotics stress remains unclear. Our results indicated that TCS suppressed plant growth by restricting photosynthesis, decreasing chlorophyll contents and inducing over production of reactive oxygen species (ROS). Interestingly, SA or glutathione (GSH) application could significantly improve plant tolerance to TCS. Moreover, endogenous SA and the expression of a SA binding protein 2 (SABP2) gene were found to be elevated in tobacco under TCS treatment. The overexpression of LcSABP, a SABP2-like gene cloned from the leaves of Lycium chinense, markedly enhanced the SA content in the transgenic plants under TCS stress. The LcSABP-overexpressing plants presented higher photosynthesis rate, chlorophyll content, glutathione reductase (GR) and glutathione-S-transferase (GST) enzymes activities, GSH content and lower O2-•, H2O2 and malondialdehyde (MDA) content in comparison with WT tobacco with TCS treatment. One of the GSH synthesis-related gene, NtGSHS, also showed higher expression level in the transgenic tobacco in comparison with control plants with TCS stress treatment. These results indicated that SABP2 played a positive regulatory role in plant response to TCS stress via increasing the endogenous SA levels. The increased SA content might then increase the GSH content, probably through an increase in GR activity and GSHS gene expression, thus inducing the antioxidant and xenobiotics detoxification systems, which promoted TCS stress tolerance in tobacco plants.


Assuntos
Esterases/genética , Lycium/genética , Proteínas de Plantas/genética , Plantas Geneticamente Modificadas/metabolismo , Estresse Fisiológico/genética , Tabaco/metabolismo , Triclosan/toxicidade , Antioxidantes/metabolismo , Clorofila/metabolismo , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Fotossíntese/efeitos dos fármacos , Fotossíntese/genética , Plantas Geneticamente Modificadas/efeitos dos fármacos , Plantas Geneticamente Modificadas/genética , Espécies Reativas de Oxigênio/metabolismo , Ácido Salicílico/farmacologia , Estresse Fisiológico/efeitos dos fármacos , Tabaco/efeitos dos fármacos , Tabaco/genética
10.
Dokl Biochem Biophys ; 486(1): 163-167, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-31367812

RESUMO

The treatment of Arabidopsis thaliana plants with exogenous cytokinin (CK) followed by heat shock (HS) activated the expression of the genes for the plastid transcription machinery but adversely affected the plant viability. Abscisic acid (ABA), conversely, promoted maintaining the resistance to HS and had differentially affected different components of the plastid transcriptional complex. This hormone suppressed the accumulation of transcripts of PEP genes and the genes encoding PAP proteins, which are involved in DNA-RNA metabolism. However, it had no effect or activated the expression of NEP genes and PAP genes, which are involved in the redox regulation, as well as the genes encoding the stress-inducible trans-factor (SIG5) and the plastid transcription Ser/Thr protein kinase (cpCK2). Thus, for the adaptation of plants to elevated temperatures, both increase and decrease in the expression of the genes for the plastid transcriptional machinery with the involvement of various regulatory systems, including phytohormones, are equally significant.


Assuntos
Ácido Abscísico/farmacologia , Arabidopsis/efeitos dos fármacos , Citocininas/farmacologia , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Resposta ao Choque Térmico/genética , Plastídeos/genética , Transcrição Genética/efeitos dos fármacos , Arabidopsis/citologia , Arabidopsis/genética , Arabidopsis/fisiologia , Resposta ao Choque Térmico/efeitos dos fármacos , Plastídeos/efeitos dos fármacos
11.
Plant Physiol Biochem ; 142: 332-341, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31377482

RESUMO

Anthocyanins are a class of compounds that are widespread in plants, where they provide protection against stresses, and are also beneficial to human health as dietary components. Melatonin application is known to affect anthocyanin production, but the relationship between anthocyanin and melatonin is still unclear. In this study, we analyzed anthocyanin contents and the expression levels of anthocyanin biosynthetic and regulatory genes in tissue cultured plantlets of two Malus crabapple cultivars following various exogenous melatonin treatments under light and dark conditions. The application of exogenous melatonin not only promoted anthocyanin accumulation in leaves, but also increased the contents of flavonols and proanthocyanins (PAs), via a process that was not dependent on light. Quantitative real time PCR (qRT-PCR) analyses indicated that the expression of flavonoid biosynthetic genes, flavonoid related transcription factors and melatonin biosynthetic genes was induced by melatonin. We propose that anthocyanin biosynthesis is regulated by melatonin in crabapple leaves via the expression of flavonoid related transcription factors. This study provides insight into the mechanism of melatonin induction of anthocyanin biosynthesis in woody plants, and suggests that pretreatment with melatonin may represent a cultivation strategy to increase the flavonoid contents of plants.


Assuntos
Antocianinas/metabolismo , Malus/efeitos dos fármacos , Melatonina/farmacologia , Folhas de Planta/efeitos dos fármacos , Antocianinas/análise , Cromatografia Líquida de Alta Pressão , Flavonóis/análise , Flavonóis/metabolismo , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Malus/química , Malus/metabolismo , Folhas de Planta/química , Folhas de Planta/metabolismo , Proteínas de Plantas/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , Fatores de Transcrição/metabolismo
12.
J Agric Food Chem ; 67(35): 9958-9966, 2019 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-31419123

RESUMO

Chilling injury (CI) is a physiological disorder induced by cold, which heavily limit crop production and postharvest preservation worldwide. Methyl jasmonate (MeJA) can alleviate CI in various fruit species, including peach; however, the underlying molecular mechanism is poorly understood. Here, changes in contents of phenolics, lipids, and jasmonic acid (JA) and gene expressions are compared between MeJA and control fruit. Exogenous MeJA inhibited expressions of PpPAL1, PpPPO1, and PpPOD1/2 but did not affect the phenolic content. Furthermore, MeJA fruit showed lower relative electrolyte leakage, indicating less membrane damage. Meanwhile, the enrichment of linoleic acid in the potential lipid biomarkers, especially phosphatidylcholine, phosphatidylethanolamine, and phosphatidylglycerol, coincided with lower expressions of PpFAD8.1 but higher PpLOX3.1 and JA content. In the JA signaling pathway, MeJA significantly upregulated expressions of PpMYC2.2 and PpCBF3 but downregulated PpMYC2.1. In conclusion, adjustments of fatty acids in phospholipids contribute to MeJA-induced alleviation of CI in peach fruit via induction of the JA-mediated C-repeat-binding factor pathway.


Assuntos
Acetatos/farmacologia , Ciclopentanos/metabolismo , Ciclopentanos/farmacologia , Frutas/efeitos dos fármacos , Oxilipinas/metabolismo , Oxilipinas/farmacologia , Fosfolipídeos/metabolismo , Reguladores de Crescimento de Planta/farmacologia , Prunus persica/metabolismo , Temperatura Baixa , Frutas/genética , Frutas/crescimento & desenvolvimento , Frutas/metabolismo , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Prunus persica/efeitos dos fármacos , Prunus persica/genética , Prunus persica/crescimento & desenvolvimento
13.
J Agric Food Chem ; 67(35): 9738-9748, 2019 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-31411877

RESUMO

The presence of chromium (Cr) in cultivated fields affects carbohydrate metabolism of rice (Oryza sativa L.) and weakens its productivity. Little is known about the molecular mechanism of sucrose metabolism underlying Cr stress response in rice plants. In the present study, the transcriptome map of sucrose metabolism in rice seedlings exposed to both trivalent and hexavalent chromium was investigated using Agilent 4 × 44K rice microarray analysis. Results indicated that Cr exposure (3 days) significantly (p < 0.05) improved sucrose accumulation, and altered the activities of sucrose synthetase, sucrose phosphate phosphatase, and amylosynthease in rice tissues. We identified 119 differentially regulated genes involved in 17 sucrose metabolizing enzymes and found that gene responses in roots were significantly (p < 0.05) stronger than in shoots under both Cr(III) and Cr(VI) treatment. The network maps of gene regulation responsible for sucrose metabolism in rice plants provide a theoretical basis for further cultivating Cr-resistant rice cultivars through molecular genetic improvement.


Assuntos
Cromo/farmacologia , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Oryza/metabolismo , Poluentes do Solo/farmacologia , Sacarose/metabolismo , Glucosiltransferases/genética , Glucosiltransferases/metabolismo , Oryza/efeitos dos fármacos , Oryza/genética , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/genética , Raízes de Plantas/metabolismo
14.
J Agric Food Chem ; 67(32): 8905-8918, 2019 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-31380641

RESUMO

NAC TFs play crucial roles in response to abiotic stresses in plants. Here, ZmNAC071 was identified as a nuclear located transcriptional repressor. Overexpression of ZmNAC071 in Arabidopsis enhanced sensitivity of transgenic plants to ABA and osmotic stress. The expression levels of SODs, PODs, P5CSs, and AtMYB61 were inhibited by ZmNAC071, which results in reduced ROS scavenging and proline content, increased ROS level, and water loss. Besides, the expression levels of some ABA or abiotic stress-related genes, like ABIs, RD29A, DREBs, and LEAs were also significantly inhibited by ZmNAC071. Yeast one-hybrid assay demonstrated that ZmNAC071 specifically bound to the cis-acting elements containing CGT[G/A] core sequences in the promoter of stress-related genes, suggesting that ZmNAC071 may participate in the regulation of transcription of these genes through recognizing the core sequences CGT[G/A]. These results will facilitate further studies concerning the cis-elements and downstream genes targeted by ZmNAC071 in maize.


Assuntos
Arabidopsis/efeitos dos fármacos , Arabidopsis/fisiologia , Ácido Ascórbico/farmacologia , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Plantas Geneticamente Modificadas/efeitos dos fármacos , Plantas Geneticamente Modificadas/fisiologia , Fatores de Transcrição/genética , Zea mays/genética , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Regulação para Baixo/efeitos dos fármacos , Pressão Osmótica , Plantas Geneticamente Modificadas/genética , Espécies Reativas de Oxigênio/metabolismo , Estresse Fisiológico , Fatores de Transcrição/metabolismo
15.
Plant Physiol Biochem ; 142: 292-302, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31351320

RESUMO

Plant extracts have recently been used as exogenous adjuvants to strengthen the endogenous plant defense systems when they grow under different environmental stresses, including salinity. The study aimed at determining the effects of seed soaking using licorice root extract (LRE) on photosynthesis and antioxidant defense systems, including transcript levels of enzyme-encoding genes in pea seedling grown under 150 mM NaCl-salinity. Salt stress reduced seedling growth, photosynthesis attributes, and K+ content, and increased oxidative stress (O2•‒ and H2O2, and MDA), Na+, and Cl-, along with an increase in antioxidative defense activities compared to control. However, LRE pretreatment enhanced seedling growth, photosynthetic attributes (chlorophylls, carotenoids, Fv/Fm, Pn, Tr, and gs), ascorbate and glutathione and their redox states, proline, soluble sugars, α-TOC, and enzyme activities compared to stressed control. LRE pretreatment also upregulated transcript levels of CAT-, SOD-, APX-, GR-, DHAR-, and PrxQ-encoding genes in salt-stressed seedlings, decreasing oxidative stress and Na+ and Cl- contents and increasing K+ content and K+/Na+ ratio.


Assuntos
Antioxidantes/metabolismo , Glycyrrhiza/química , Ervilhas/efeitos dos fármacos , Extratos Vegetais/farmacologia , Raízes de Plantas/química , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Ervilhas/metabolismo , Ervilhas/fisiologia , Fotossíntese/efeitos dos fármacos , Tolerância ao Sal/efeitos dos fármacos , Plântula/efeitos dos fármacos , Plântula/metabolismo
16.
Mol Genet Genomics ; 294(6): 1511-1525, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31324970

RESUMO

DNA methylation and long non-coding RNAs (lncRNAs) regulate plant growth and development, but their relationship and effect on responses to the auxin phytohormone indole-3-acetic acid (IAA) remain largely unknown, particularly in woody plants such as poplar (Populus tomentosa). Following treatment of 1-year-old clonal plants with 100 µM IAA, key poplar lncRNA genes showed changes in methylation, but whole-genome methylation levels showed no significant change. Moreover, 100 µM IAA inhibited growth of the 1-year-old poplar clones, possibly through the suppression of photosynthesis. This inhibition had a long-term effect, persisting at 1 month after removal of the exogenous IAA. Transcriptome analysis identified two candidate lncRNA genes that show changes in expression following IAA treatment, TCONS_00003480 and TCONS_00004832. TCONS_00003480 contains the same microRNA target sites of ptc-miR6464 as the 4-coumarate: CoA ligase 2 transcript, which encodes a lignin biosynthesis enzyme. And TCONS_00004832 shares the same target sites of ptc-miR6437a with the Photosystem II reaction center protein D and Cytochrome C Oxidase 17 transcripts, which are related to photosynthesis. The two lncRNAs as the mimics to corresponding target genes of miRNAs to prevent them from degrading. Examination of lncRNA gene expression and methylation revealed a negative relationship (r = - 0.29, P < 0.05); moreover, hypermethylation of the two candidate lncRNA genes remained 1 month after IAA treatment, suggesting that changes in methylation might be involved in the long-term effects of plant hormones. Therefore, our study reveals a long-term effect of IAA on the growth of P. tomentosa, possibly via methylation-mediated epigenetic changes in lncRNA gene expression and the interaction with corresponding miRNAs, leading to regulation of genes related to photosynthesis and growth.


Assuntos
Metilação de DNA , Regulação da Expressão Gênica de Plantas , Ácidos Indolacéticos/farmacologia , Reguladores de Crescimento de Planta/farmacologia , Populus/genética , RNA Longo não Codificante/genética , Parede Celular/metabolismo , Metilação de DNA/efeitos dos fármacos , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , MicroRNAs/metabolismo , Fotossíntese/efeitos dos fármacos , Populus/efeitos dos fármacos , Populus/crescimento & desenvolvimento , Populus/metabolismo , RNA Longo não Codificante/metabolismo
17.
Plant Physiol Biochem ; 142: 263-274, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31330393

RESUMO

To explain the underlying mechanism of melatonin-mediated drought stress responses in maize, maize pre-treated with or without melatonin was subjected to 20% PEG nutrient solution to induce drought stress. We found that exogenous melatonin significantly improved drought tolerance, demonstrated by improved photosynthesis, reduced ROS accumulation, enhanced activities of superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT), and increased content of glutathione (GSH). Comparative iTRAQ proteomic analyses revealed a higher abundance of differentially expressed proteins (DEPs) in melatonin-treated maize under drought stress for carbon fixation in photosynthetic organisms, photosynthesis, biosynthesis of amino acids, and biosynthesis of secondary metabolites, compared to untreated plants. Changes in the above molecular mechanisms could explain the melatonin-induced physiological effects associated with drought tolerance. In summary, this study provides a more integrated picture about the effects of melatonin on the physiological and molecular mechanisms in maize seedlings responding to drought stress.


Assuntos
Melatonina/metabolismo , Estresse Oxidativo , Folhas de Planta/metabolismo , Zea mays/metabolismo , Catalase/metabolismo , Desidratação , Relação Dose-Resposta a Droga , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Glutationa/metabolismo , Melatonina/farmacologia , Melatonina/fisiologia , Peroxidase/metabolismo , Folhas de Planta/efeitos dos fármacos , Folhas de Planta/fisiologia , Proteômica , Reação em Cadeia da Polimerase em Tempo Real , Superóxido Dismutase/metabolismo , Zea mays/efeitos dos fármacos , Zea mays/fisiologia
18.
Food Chem ; 299: 125116, 2019 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-31295637

RESUMO

The effects of exogenous melatonin treatment on the enzymatic browning and nutritional quality of fresh-cut pear fruit were investigated. Fresh-cut fruit soaked with 0, 0.05, 0.1 and 0.5 mM melatonin were stored at 4 °C. Our results showed that 0.1 mM melatonin treatment was optimal for reducing the surface browning and maintaining the titratable acidity of the fresh-cut fruit, which significantly decreased MDA and H2O2 contents and the growth of microorganism, enhanced total phenolic content and antioxidant capacity, and delayed the reduction of ascorbic acid. Furthermore, melatonin treatment at 0.1 mM decreased the expression of genes involving in enzymatic browning pathway including POD, PPO1, PPO5 and LOX1, and reduced PPO activity. Moreover, this treatment increased the expression of PAL and CHS, and enhanced PAL and CHS activities. These results showed that melatonin treatment might be a promising strategy to alleviate browning and improve the nutritional quality of fresh-cut pear fruit.


Assuntos
Frutas/efeitos dos fármacos , Melatonina/farmacologia , Valor Nutritivo , Pyrus/efeitos dos fármacos , Antioxidantes/análise , Antioxidantes/metabolismo , Ácido Ascórbico/análise , Ácido Ascórbico/metabolismo , Armazenamento de Alimentos , Frutas/química , Frutas/metabolismo , Frutas/microbiologia , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Peróxido de Hidrogênio/análise , Peróxido de Hidrogênio/metabolismo , Malondialdeído/análise , Malondialdeído/metabolismo , Fenóis/análise , Pyrus/química , Pyrus/genética , Pyrus/metabolismo
19.
Food Chem ; 299: 125138, 2019 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-31302430

RESUMO

As an environmentally friendly approach for fruit quality improvement, the effect of preharvest UV-C on the physiology of strawberry fruit during postharvest storage remains to be assessed. Strawberry fruit developed with supplementary UV-C were stored at room temperature for 2 weeks. Preharvest UV-C attenuated fruit postharvest senescence and altered phytochemicals composition. Higher ester titer was found in the treated fruit at harvest, whereas higher terpene and furanone contents were detected after 72 h of storage. At harvest, polyphenolics accumulated to a higher level in UV-C group, but the difference disappeared after 24 h of storage. Meanwhile, the intrinsic level of abscisic acid and the expressions of FaPYR1, SnRK2, and FaASR in the UV-C-treated fruit was enhanced at harvest but returned to a lower level as storage proceeded. This study highlights the time-dependent effect of preharvest UV-C on strawberry fruit postharvest biochemical indexes and the possible involvement of abscisic acid signaling factors.


Assuntos
Ácido Abscísico/metabolismo , Armazenamento de Alimentos/métodos , Fragaria/fisiologia , Frutas/fisiologia , Compostos Fitoquímicos/metabolismo , Ácido Abscísico/genética , Fragaria/química , Fragaria/efeitos da radiação , Frutas/química , Frutas/metabolismo , Frutas/efeitos da radiação , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Compostos Fitoquímicos/análise , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Polifenóis/análise , Polifenóis/metabolismo , Terpenos/análise , Terpenos/metabolismo , Raios Ultravioleta
20.
J Sci Food Agric ; 99(14): 6418-6430, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31294466

RESUMO

BACKGROUND: Dracocephalum kotschyi Boiss. is a valuable source of rosmarinic acid (RA) and methoxylated hydroxyflavones (such as xanthomicrol and cirsimaritin) with antioxidative and antiplatelet effects and with antiproliferative potential against various cancer cells. The extensive application of nanotechnology in hairy root cultures is a new sustainable production platform for producing these active constituents. In the present study, hairy roots derived from 4-week-old leaves and Agrobacterium rhizogenes strain ATCC15834 were used to investigate the impact of various concentrations of iron oxide nanoparticles (Fe NPs) in two elicitation time exposures (24 and 48 h) on growth, antioxidant enzyme activity, total phenolic and flavonoid content (TPC and TFC), and some polyphenols. Gene expression levels of phenylalanine ammonia-lyase (pal) and rosmarinic acid synthase (ras) were also analyzed. RESULTS: Iron nanoparticles enhanced biomass accumulation in hairy roots. The treatment time and Fe NP dosage largely improved the activity of antioxidant enzymes, TPC and TFC. The highest RA (1194 µg g-1 FW) content (9.7-fold), compared to controls, was detected with 24 h of exposure to 75 mg L-1 Fe NP, which was consistent with the expression of pal and ras genes under the influence of elicitation. The xanthomicrol, cirsimaritin, and isokaempferide content was increased 11.87, 3.85, and 2.27-fold, respectively. CONCLUSION: Stimulation of D. kotschyi hairy roots by Fe NPs led to a significant increase in the induction and production of important pharmaceutical compounds such as rosmarinic acid and xanthomicrol. © 2019 Society of Chemical Industry.


Assuntos
Antineoplásicos Fitogênicos/biossíntese , Compostos Férricos/farmacologia , Flavonoides/biossíntese , Lamiaceae/efeitos dos fármacos , Lamiaceae/metabolismo , Proteínas de Plantas/genética , Raízes de Plantas/crescimento & desenvolvimento , Antineoplásicos Fitogênicos/farmacologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Flavonoides/farmacologia , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Humanos , Lamiaceae/genética , Lamiaceae/crescimento & desenvolvimento , Nanopartículas/química , Fenilalanina Amônia-Liase/genética , Fenilalanina Amônia-Liase/metabolismo , Proteínas de Plantas/metabolismo , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/genética , Raízes de Plantas/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA