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1.
BMC Plant Biol ; 19(1): 368, 2019 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-31429706

RESUMO

BACKGROUND: We previously reported the involvement of nitric oxide (NO) and cyclic nucleotide-gated ion channel 6 (CNGC6) in the responses of plants to heat shock (HS) exposure. To elucidate their relationship with heat tolerance in Arabidopsis thaliana, we examined the effects of HS on several groups of seedlings: wild type, cngc6, and cngc6 complementation and overexpression lines. RESULTS: After HS exposure, the level of NO was lower in cngc6 seedlings than in wild-type seedlings but significantly elevated in the transgenic lines depending on CNGC6 expression level. The treatment of seeds with calcium ions (Ca2+) enhanced the NO level in Arabidopsis seedlings under HS conditions, whereas treatment with EGTA (a Ca2+ chelator) reduced it, implicating that CNGC6 stimulates the accumulation of NO depending on an increase in cytosolic Ca2+ ([Ca2+]cyt). This idea was proved by phenotypic observations and thermotolerance testing of transgenic plants overexpressing NIA2 and NOA1, respectively, in a cngc6 background. Western blotting indicated that CNGC6 stimulated the accumulation of HS proteins via NO. CONCLUSION: These data indicate that CNGC6 acts upstream of NO in the HS pathway, which improves our insufficient knowledge of the initiation of plant responses to high temerature.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Cálcio/metabolismo , Canais de Cátion Regulados por Nucleotídeos Cíclicos/metabolismo , Óxido Nítrico/metabolismo , Termotolerância , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Canais de Cálcio/metabolismo , Canais de Cátion Regulados por Nucleotídeos Cíclicos/genética , Citosol/metabolismo , Proteínas de Choque Térmico/genética , Proteínas de Choque Térmico/metabolismo , Resposta ao Choque Térmico , Mutação , Nitrato Redutase/genética , Nitrato Redutase/metabolismo , Óxido Nítrico Sintase/genética , Óxido Nítrico Sintase/metabolismo , Plântula/genética , Plântula/metabolismo
2.
J Agric Food Chem ; 67(35): 9772-9781, 2019 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-31398019

RESUMO

This study aims to investigate the response profiles of vitamin E and carotenoids on transcription and metabolic levels of sweet corn seedlings under temperature stress. The treated temperatures were set as 10 °C (low temperature, LT), 25 °C (control, CK), and 40 °C (high temperature, HT) for sweet corn seedlings. The gene expression profiles of vitamin E and carotenoids biosynthesis pathways were analyzed by real time quantitative polymerase chain reaction (RT-qPCR), and the composition profiles were analyzed by high performance liquid chromatography (HPLC). Results showed that vitamin E gradually accumulated in response to LT stress but was limited by HT stress. The increase of carotenoids was suppressed by LT stress whereas HT stress promoted it. The existing results elaborated the interactive and competitive relationships of vitamin E and carotenoids in sweet corn seedlings to respond to extreme temperature stress at transcriptional and metabolic levels. The present study would improve sweet corn temperature resilience with integrative knowledge in the future.


Assuntos
Carotenoides/metabolismo , Vitamina E/metabolismo , Zea mays/metabolismo , Carotenoides/análise , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plântula/química , Plântula/genética , Plântula/crescimento & desenvolvimento , Plântula/metabolismo , Estresse Fisiológico , Temperatura Ambiente , Vitamina E/análise , Zea mays/química , Zea mays/genética , Zea mays/crescimento & desenvolvimento
3.
J Environ Sci (China) ; 84: 155-165, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31284907

RESUMO

Nitrogen dioxide (NO2) is an important substance in atmospheric photochemical processes and can also be absorbed by plants. NO2 fluxes between the atmosphere and P. nigra seedlings were investigated by a double dynamic chambers method in Beijing from June 15 to September 3, 2017. The range of NO2 exchange fluxes between P. nigra seedlings and the atmosphere was from -14.6 to 0.8 nmol/(m2·sec) (the positive data represent NO2 emission from trees, while the negative values indicate absorption). Under ambient concentrations, the mean NO2 flux during the fast-growing stage (Jun. 15-Aug. 4) was -3.0 nmol/(m2·sec), greater than the flux of -1.5 nmol/(m2·sec) during the later growth stage (Aug. 8-Sept. 3). The daily exchange fluxes of NO2 obviously fluctuated. The fluxes were largest in the morning and decreased gradually over time. Additionally, the NO2 fluxes were larger under high light intensities than under low light intensities during the whole growth period. The effects of temperature on NO2 fluxes were different under two growth periods. The NO2 exchange fluxes were larger in a range of temperatures close to 44°C in the fast-growing stage, whereas there were no evident differences in NO2 exchange fluxes under widely differing temperatures in the later growth stage. Under polluted conditions, the uptake ability of NO2 was weakened. Additionally, the compensation point of NO2 was 5.6 ppb in the fast-growing stage, whereas it was 1.4 ppb in the later growth stage. The deposition velocities of NO2 were between 0.3 and 2.4 mm/sec.


Assuntos
Dióxido de Nitrogênio/metabolismo , Plântula/metabolismo , Atmosfera , Umidade , Pinus , Estações do Ano
4.
Physiol Plant ; 166(4): 892-893, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31294874

RESUMO

Drought is an increasingly common climatic event that can devastate ecosystems, as well as surrounding agricultural and forestry industries. Few places face this challenge more than Australia, where millennia of droughts linked to geography and climatic drivers, such as El Niño, have shaped the flora and fauna into forms predicated on resilience and economy. How an organism responds to these cyclic challenges is a combination of the inherent tolerance mechanisms encoded in their genome and outside influences, such as the effect of nutrients and symbiotic interactions. In this issue of Physiologia Plantarum, Tariq et al. (2019) describes how the presence of the element phosphorus can bolster the physiological and biochemical response of eucalypt seedlings to severe drought conditions.


Assuntos
Secas , Genoma de Planta/genética , Fósforo/metabolismo , Plântula/genética , Plântula/metabolismo , Austrália
5.
Genome Biol ; 20(1): 139, 2019 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-31307500

RESUMO

BACKGROUND: Bread wheat is an allohexaploid species with a 16-Gb genome that has large intergenic regions, which presents a big challenge for pinpointing regulatory elements and further revealing the transcriptional regulatory mechanisms. Chromatin profiling to characterize the combinatorial patterns of chromatin signatures is a powerful means to detect functional elements and clarify regulatory activities in human studies. RESULTS: In the present study, through comprehensive analyses of the open chromatin, DNA methylome, seven major chromatin marks, and transcriptomic data generated for seedlings of allohexaploid wheat, we detected distinct chromatin architectural features surrounding various functional elements, including genes, promoters, enhancer-like elements, and transposons. Thousands of new genic regions and cis-regulatory elements are identified based on the combinatorial pattern of chromatin features. Roughly 1.5% of the genome encodes a subset of active regulatory elements, including promoters and enhancer-like elements, which are characterized by a high degree of chromatin openness and histone acetylation, an abundance of CpG islands, and low DNA methylation levels. A comparison across sub-genomes reveals that evolutionary selection on gene regulation is targeted at the sequence and chromatin feature levels. The divergent enrichment of cis-elements between enhancer-like sequences and promoters implies these functional elements are targeted by different transcription factors. CONCLUSIONS: We herein present a systematic epigenomic map for the annotation of cis-regulatory elements in the bread wheat genome, which provides new insights into the connections between chromatin modifications and cis-regulatory activities in allohexaploid wheat.


Assuntos
Montagem e Desmontagem da Cromatina , Metilação de DNA , Código das Histonas , Elementos Reguladores de Transcrição , Triticum/genética , Evolução Biológica , Epigenômica , Genoma de Planta , Plântula/metabolismo , Triticum/metabolismo
6.
BMC Plant Biol ; 19(1): 320, 2019 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-31319813

RESUMO

BACKGROUND: Plant cell walls participate in all plant-environment interactions. Maintaining cell wall integrity (CWI) during these interactions is essential. This realization led to increased interest in CWI and resulted in knowledge regarding early perception and signalling mechanisms active during CWI maintenance. By contrast, knowledge regarding processes mediating changes in cell wall metabolism upon CWI impairment is very limited. RESULTS: To identify genes involved and to investigate their contributions to the processes we selected 23 genes with altered expression in response to CWI impairment and characterized the impact of T-DNA insertions in these genes on cell wall composition using Fourier-Transform Infrared Spectroscopy (FTIR) in Arabidopsis thaliana seedlings. Insertions in 14 genes led to cell wall phenotypes detectable by FTIR. A detailed analysis of four genes found that their altered expression upon CWI impairment is dependent on THE1 activity, a key component of CWI maintenance. Phenotypic characterizations of insertion lines suggest that the four genes are required for particular aspects of CWI maintenance, cell wall composition or resistance to Plectosphaerella cucumerina infection in adult plants. CONCLUSION: Taken together, the results implicate the genes in responses to CWI impairment, cell wall metabolism and/or pathogen defence, thus identifying new molecular components and processes relevant for CWI maintenance.


Assuntos
Arabidopsis/genética , Parede Celular/metabolismo , Genes de Plantas/fisiologia , Arabidopsis/metabolismo , Arabidopsis/fisiologia , Ascomicetos , Parede Celular/fisiologia , Resistência à Doença/genética , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas/genética , Técnicas de Silenciamento de Genes , Interações Hospedeiro-Patógeno , Doenças das Plantas/imunologia , Plântula/metabolismo , Plântula/fisiologia , Espectroscopia de Infravermelho com Transformada de Fourier
7.
Ecotoxicol Environ Saf ; 181: 491-498, 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31229839

RESUMO

Indian mustard (Brassica juncea L.) was more tolerance to Cs than some sensitive plants, such as Arabidopsis thaliana and Vicia faba, and may have a special detoxification mechanism. In this study, the effects on reactive oxygen species (ROS) content, the antioxidant enzyme system and chelation system in Indian mustard were studied by observing different plant physiological responses. In addition, we focused on the analysis of gene regulatory networks related to ROS formation, ROS scavenging system, and other stress-response genes to Cs exposure using a transcriptome-sequencing database. The results showed that ROS and malonaldehyde content in seedlings increased significantly in Cs-treatment groups. The enzyme activities of superoxide dismutase, peroxidase, catalase, and ascorbate peroxidase were increased, and the synthesis of antioxidants glutathione, phytochelatin and metallothionein also increased under Cs treatment. Further analysis showed that ROS formation pathways were primarily the photosynthetic electron transport chain process and photorespiration process in the peroxisome. Antioxidant enzyme systems and the respiratory burst oxidase homolog protein-mediated signal transduction pathway played a key role in ROS scavenging. In summary, one of the mechanisms of tolerance and detoxification of Indian mustard to Cs was that it enhanced the scavenging ability of antioxidant enzymes to ROS, chelated free Cs ions in cells and regulated the expression of related disease-resistant genes.


Assuntos
Antioxidantes/metabolismo , Césio/metabolismo , Mostardeira/fisiologia , Poluentes do Solo/metabolismo , Estresse Fisiológico/genética , Redes Reguladoras de Genes , Mostardeira/enzimologia , Mostardeira/genética , Mostardeira/metabolismo , Oxirredução , Fitoquelatinas/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Plântula/enzimologia , Plântula/metabolismo
8.
Ecotoxicol Environ Saf ; 181: 345-352, 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31202935

RESUMO

Nanomaterials are being used increasingly in various areas such as electronic devices manufacture, medicine, mechanical devices production, and even food industry. Therefore, the evaluation of their toxicity is mandatory. Graphene oxide (GO) has been shown to have both positive as well as negative impact on different crop plants, depending on species, dose, and duration of exposure. The current study evaluated the impact of GO sheets at different concentrations (500, 1000 and 2000 mg/L) on physiological, biochemical and genetic levels to determine the possible toxic action. Wheat caryopses were treated with GO for 48 h and 7 days. The germination rate and roots elongation decreased in a dose-response manner, except the sample treated with GO at a concentration of 1000 mg/L. Mitotic index has ascendant trend; its increase may be due to the accumulation of prophases GO induced significant accumulation of the cells with aberrations, their presence suggests a clastogenic/aneugenic effect of these carbon nanomaterials. Regarding enzymatic and non-enzymatic antioxidant system defence, the activity varied depending on the dose of GO. Thus, chlorophyll a pigments content decreased significantly at high dose (2000 mg/L), while the carotenoid pigments had lower content at 500 mg/L of GO, and no statistical difference encountered in case of chlorophyll b amount. The antioxidant enzyme activity (CAT, POD, and SOD) was higher at low dose of GO, indicating the presence of oxidative stress generated as a response to the GO treatment. Also, the free radical scavenging activity of the polyphenolic compounds was enhanced upon GO exposure. The GO accumulation has been identified by transmission electron microscopy only at plumules level, near the intercellular space.


Assuntos
Grafite/toxicidade , Nanoestruturas/toxicidade , Triticum/efeitos dos fármacos , Antioxidantes/metabolismo , Clorofila/metabolismo , Clorofila A/metabolismo , Germinação/efeitos dos fármacos , Estresse Oxidativo , Óxidos/toxicidade , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/crescimento & desenvolvimento , Plântula/efeitos dos fármacos , Plântula/enzimologia , Plântula/metabolismo , Triticum/enzimologia , Triticum/crescimento & desenvolvimento , Triticum/metabolismo
9.
Plant Physiol Biochem ; 141: 466-476, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31252252

RESUMO

The present study was aimed to investigate adaptation in physiology and biochemistry of Solanum lycopersicum seedlings under NaCl (NaCl0; 0.0 g NaCl kg-1 sand, NaCl1; 0.3 g NaCl/kg sand and NaCl2; 0.5 g NaCl/kg sand) stress, simultaneously supplemented with different (deprived; 0 mg/kg sand, LN; 105 mg/kg sand, MN; 210 mg/kg sand and HN; 270 mg/kg sand) levels of nitrogen (N). NaCl at both doses caused significant loss in growth, K+ content, K+/Na+ ratio, total chlorophyll and photosynthetic oxygen evolution. Further, N supplementation influences growth of test seedlings, that attained maximum growth in HN followed by MN, LN and deprived N conditions. N at HN level significantly declined Na+ accumulation in the cell and enhanced level of K+. NaCl treatment enhanced level of oxidative stress biomarkers: superoxide radical (O2•-), hydrogen peroxide (H2O2), MDA equivalents contents and electrolyte leakage in leaf as well as root despite enhanced activity of SOD, POD, CAT and GST, and enzymes participating in the ascorbate-glutathione cycle (AsA-GSH cycle) viz. APX, DHAR and GR. At the same time, higher contents of total AsA (AsA + DHA) and total GSH (GSH + GSSG), and maintained ratios of AsA/DHA and GSH/GSSG in HN fed seedlings were observed. Overall, the results suggest that HN supplementation was able in alleviating NaCl induced toxicity in test seedlings which was mainly due to the up-regulation of the AsA-GSH cycle, K+ and K+/Na+ ratio, which resulted into better growth performance of HN fed seedlings under NaCl stress while reverse was noticed for LN and deprive N conditions.


Assuntos
Lycopersicon esculentum/metabolismo , Nitrogênio/química , Espécies Reativas de Oxigênio/metabolismo , Salinidade , Antioxidantes/metabolismo , Ácido Ascórbico/metabolismo , Biomarcadores/metabolismo , Clorofila/metabolismo , Glutationa/metabolismo , Peróxido de Hidrogênio/metabolismo , Peroxidação de Lipídeos , Malondialdeído/metabolismo , Estresse Oxidativo , Oxigênio/metabolismo , Fotossíntese , Pigmentação , Folhas de Planta/metabolismo , Raízes de Plantas/metabolismo , Brotos de Planta/metabolismo , Potássio/química , Plântula/metabolismo , Cloreto de Sódio/química
10.
Plant Physiol Biochem ; 141: 477-486, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31252253

RESUMO

The induction of leaf injuries, including leaf chlorosis and epinasty, by continuous light in tomato plants is one of the most interesting and mysterious phenomena regarding plant interactions with light, the mechanism of which has not yet been revealed. To gain further insights into this particular response of tomato plants, we cultivated tomato seedlings (Solanum lycopersicum cv. Momotaro) for 14 days under continuous light with different ratios of red and blue light and compared their performance to those grown under continuous or 14/10-h photoperiodic white light using novel methods to quantitatively evaluate the level of leaf chlorosis and epinasty. Continuous monochromatic blue light induced severe chlorosis but almost completely alleviated epinasty in tomato leaf. In contrast, continuous monochromatic red light caused a lower level of leaf chlorosis but very severe epinasty. The combination of red and blue light at different ratios significantly reduced both leaf chlorosis and epinasty under continuous light condition. Carbohydrate contents showed no correlation with leaf chlorosis, while glucose and fructose contents showed correlations with the petiole and leaflet curvatures. Histochemical staining with 3,3'-diaminobenzidine and nitro blue tetrazodium chloride also did not reveal any significant buildup of hydrogen peroxide and superoxide anion in monochromatic blue light treatment. Taken together, these results suggest that chlorosis and epinasty are two distinctive leaf injuries caused by continuous light that may follow very different mechanisms, and an overaccumulation of carbohydrates in the leaf may not be the main cause of continuous light-induced leaf chlorosis in tomato.


Assuntos
Luz , Lycopersicon esculentum/efeitos da radiação , Folhas de Planta/efeitos da radiação , 3,3'-Diaminobenzidina/química , Anemia Hipocrômica/metabolismo , Carboidratos/química , Cor , Frutose/química , Glucose/química , Peróxido de Hidrogênio/química , Lycopersicon esculentum/crescimento & desenvolvimento , Oxigênio/química , Fotoquímica , Fotoperíodo , Fotossíntese , Doenças das Plantas , Proteínas de Plantas/metabolismo , Plântula/metabolismo , Sais de Tetrazólio/química
11.
Food Chem ; 296: 150-159, 2019 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-31202299

RESUMO

Sea fennel is an herbaceous aromatic and edible halophyte, naturally occurring in coastal areas of the Mediterranean basin. Besides its scientific interest as a salt-tolerant species it exhibits considerable nutritional value and economical potential. As sea fennel is distributed in maritime areas, where natural iodine is available in high concentrations, the aim of this study was to evaluate whether sea fennel has the potential to accumulate elevated iodine concentrations under cultivation. A biofortification experiment in a hydroponic system applying two forms of iodine, KI and KIO3 in different concentrations was set up and monitored using sophisticated targeted elementary and metabolite analysis. The biofortification potential and possible effects on nutritional value were investigated. This study revealed that both iodine forms increased the iodine content of sea fennel tissues. Nutritional and health promoting components, biomass production but also antioxidant potential were stable or even improved under the iodine treatments.


Assuntos
Apiaceae/metabolismo , Hidroponia/métodos , Iodo/química , Valor Nutritivo , Apiaceae/crescimento & desenvolvimento , Biofortificação , Biomassa , Carotenoides/análise , Carotenoides/isolamento & purificação , Cromatografia Líquida de Alta Pressão , Cromatografia Gasosa-Espectrometria de Massas , Extratos Vegetais/análise , Plântula/metabolismo , Compostos Orgânicos Voláteis/análise
12.
Environ Sci Pollut Res Int ; 26(22): 23192-23197, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31187379

RESUMO

Soil alkalinity caused by salts, such as sodium bicarbonate (NaHCO3), and the frequently associated waterlogging problems are pervasive in agriculture and have a deleterious impact on crop production. However, various plant growth regulators, including brassinosteroids, are considered to be important against different abiotic stresses experienced by plants due to drought, salinity, and heavy metal stress. We investigated the putative role of 24-epibrassinolide (EBL), an active brassinosteroid, on red rice plants experiencing alkaline stress. Seedlings were pre-treated with 0.01 µM EBL for 30 min and later, exposed to NaHCO3 (25 mM) and were sampled, 5 days after treatments. Results showed that the pre-treatment of seedlings with EBL under non-stress conditions could promote rice plant growth. Growth parameters including dry weight (DW), root and coleoptile lengths were reduced under alkaline stress, whereas EBL application reduced the level of inhibition, as compared with NaHCO3 treatment. Enhanced levels of malondialdehyde content, hydrogen peroxide, and superoxide radicals were significantly diminished by EBL pre-treatment. Moreover, pre-treatment of EBL to alkaline-treated rice seedlings largely stimulated the enzymatic activities of ascorbate peroxidase, catalase, and superoxide dismutase. Thus, the results suggest that pre-application of EBL significantly ameliorates alkaline stress in rice.


Assuntos
Ascorbato Peroxidases/química , Brassinosteroides/farmacologia , Catalase/metabolismo , Oryza/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Reguladores de Crescimento de Planta/farmacologia , Plântula/metabolismo , Estresse Fisiológico/efeitos dos fármacos , Superóxido Dismutase/metabolismo , Ascorbato Peroxidases/metabolismo , Peróxido de Hidrogênio/química , Malondialdeído/química , Plântula/efeitos dos fármacos , Esteroides Heterocíclicos , Superóxido Dismutase/química
13.
J Microbiol Biotechnol ; 29(6): 877-886, 2019 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-31154743

RESUMO

Brewing with buckwheat as an ingredient has been proven to be successful in several previous studies. However, few studies have focused on the effects of buckwheat on the rutin content and antioxidant activity of beer. In order to develop a lager beer with high rutin content and desirable sensory characteristics, tartary buckwheat malt was used as a brewing adjunct. The results showed that the rutin-degrading enzyme was the key factor affecting the rutin content in the wort and beer. Compared to beer made using the common mashing method, the rutin content in the buckwheat beers produced using an improved mashing method was approximately 60 times higher. The total flavonoid contents in buckwheat beers also depended strongly on the mashing methods, ranging from 530.75 to 1,704.68 mg QE/l. The rutin-rich beers also showed better oxidative stability during forced-aging. Meanwhile, the buckwheat beers were found to be acceptable in terms of the main quality attributes, flavor, and taste.


Assuntos
Cerveja/análise , Fagopyrum/química , Rutina/química , Amilases/metabolismo , Antioxidantes/metabolismo , Fagopyrum/metabolismo , Fermentação , Flavonoides/química , Manipulação de Alimentos , Hordeum/química , Hordeum/metabolismo , Quercetina/química , Rutina/metabolismo , Plântula/química , Plântula/metabolismo , Sensação , Paladar
14.
Nat Commun ; 10(1): 2222, 2019 05 20.
Artigo em Inglês | MEDLINE | ID: mdl-31110237

RESUMO

Substrates associate and products dissociate from enzyme catalytic sites rapidly, which hampers investigations of their trajectories. The high-resolution structure of the native Hordeum exo-hydrolase HvExoI isolated from seedlings reveals that non-covalently trapped glucose forms a stable enzyme-product complex. Here, we report that the alkyl ß-D-glucoside and methyl 6-thio-ß-gentiobioside substrate analogues perfused in crystalline HvExoI bind across the catalytic site after they displace glucose, while methyl 2-thio-ß-sophoroside attaches nearby. Structural analyses and multi-scale molecular modelling of nanoscale reactant movements in HvExoI reveal that upon productive binding of incoming substrates, the glucose product modifies its binding patterns and evokes the formation of a transient lateral cavity, which serves as a conduit for glucose departure to allow for the next catalytic round. This path enables substrate-product assisted processive catalysis through multiple hydrolytic events without HvExoI losing contact with oligo- or polymeric substrates. We anticipate that such enzyme plasticity could be prevalent among exo-hydrolases.


Assuntos
Domínio Catalítico , Glucosidases/metabolismo , Modelos Moleculares , Proteínas de Plantas/metabolismo , Biocatálise , Cristalografia por Raios X , Ensaios Enzimáticos/métodos , Glucosidases/química , Glucosidases/isolamento & purificação , Glicosídeos/metabolismo , Hordeum/metabolismo , Simulação de Dinâmica Molecular , Ressonância Magnética Nuclear Biomolecular , Proteínas de Plantas/química , Proteínas de Plantas/isolamento & purificação , Proteínas Recombinantes/isolamento & purificação , Proteínas Recombinantes/metabolismo , Plântula/metabolismo , Especificidade por Substrato
15.
Plant Physiol Biochem ; 140: 105-112, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31091491

RESUMO

Abscisic acid (ABA) is one of the main participants in the regulation of plant responses to water deficiency. Knowledge of the ABA signal transduction pathways in gymnosperms is rather limited, especially in comparison with those in angiosperms. Seedlings of Scots pine and Norway spruce are known for their contrasting behaviour strategies under water deficit. To characterize the possible role of ABA in these differences, ABA dynamics were investigated under conditions of water deficit in seedlings of these two species. The content of ABA and its catabolites was followed in the roots and needles of seedlings of Pinus sylvestris and Picea abies under conditions of polyethylene glycol (PEG)-induced water deficiency (-0.15 and -0.5 MPa) for 10 days. The expression of the main genes for ABA-biosynthetic enzymes was also analysed. ABA showed more pronounced stress-dependent dynamics in pine roots than in spruce roots, whereas in needles, the response was greater for spruce than pine. The ABA increase during drought was mainly due to de novo synthesis and the shift in the balance between ABA synthesis and catabolism towards synthesis. The ABA-glucosyl ester did not serve as a reserve for the release of free ABA under water deficiency. The expression levels of the main ABA biosynthetic genes showed a weak or no correlation with changes in ABA content under water stress, i.e., the ABA content in the seedlings of both species was not directly linked to the transcript levels of the main ABA biosynthetic genes. Less-pronounced stress-induced changes in ABA in pine needles than in spruce needles may be related to pine seedlings having a less conservative strategy of growth and maintenance of water balance under water deficit.


Assuntos
Ácido Abscísico/metabolismo , Secas , Picea/metabolismo , Pinus sylvestris/metabolismo , Desidratação , Picea/efeitos dos fármacos , Pinus sylvestris/efeitos dos fármacos , Polietilenoglicóis/farmacologia , Plântula/efeitos dos fármacos , Plântula/metabolismo
16.
Int J Mol Sci ; 20(9)2019 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-31075903

RESUMO

Boron (B) is a micronutrient for plant development, and its deficiency alters many physiological processes. However, the current knowledge on how plants are able to sense the B-starvation signal is still very limited. Recently, it has been reported that B deprivation induces an increase in cytosolic calcium concentration ([Ca2+]cyt) in Arabidopsis thaliana roots. The aim of this work was to research in Arabidopsis whether [Ca2+]cyt is restored to initial levels when B is resupplied and elucidate whether apoplastic Ca2+ is the major source for B-deficiency-induced rise in [Ca2+]cyt. The use of chemical compounds affecting Ca2+ homeostasis showed that the rise in root [Ca2+]cyt induced by B deficiency was predominantly owed to Ca2+ influx from the apoplast through plasma membrane Ca2+ channels in an IP3-independent manner. Furthermore, B resupply restored the root [Ca2+]cyt. Interestingly, expression levels of genes encoding Ca2+ transporters (ACA10, plasma membrane PIIB-type Ca2+-ATPase; and CAX3, vacuolar cation/proton exchanger) were upregulated by ethylene glycol tetraacetic acid (EGTA) and abscisic acid (ABA). The results pointed out that ACA10, and especially CAX3, would play a major role in the restoration of Ca2+ homeostasis after 24 h of B deficiency.


Assuntos
Arabidopsis/metabolismo , Boro/deficiência , Sinalização do Cálcio , Cálcio/metabolismo , Citosol/metabolismo , Arabidopsis/genética , Boro/farmacologia , Sinalização do Cálcio/efeitos dos fármacos , Citosol/efeitos dos fármacos , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/genética , Raízes de Plantas/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Plântula/efeitos dos fármacos , Plântula/metabolismo
17.
BMC Genomics ; 20(1): 381, 2019 May 16.
Artigo em Inglês | MEDLINE | ID: mdl-31096913

RESUMO

BACKGROUND: Salinization seriously threatens land use efficiency and crop yields across the world. Understanding the mechanisms plants use to protect against salt stress will help breeders develop salt-tolerant vegetable crops. Okra (Abelmoschus esculentus L.) is an important vegetable crop of the mallow family, which is now cultivated in warm regions worldwide. To understand the effects of salt stress on the protein level of okra, a comparative proteomic analysis of okra seedlings grown in the presence of 0 or 300 mmol L- 1 NaCl treatment was performed using an integrated approach of Tandem Mass Tag labeling and LC-MS/MS integrated approach. RESULTS: A total of 7179 proteins were identified in this study, for which quantitative information was available for 5774 proteins. In the NaCl/control comparison group, there were 317 differentially expressed proteins (DEPs), of which 165 proteins were upregulated and 152 proteins downregulated in the presence of NaCl. Based on the above data, we carried out a systematic bioinformatics analysis of proteins with information, including protein annotation, domain characteristics, functional classification, and pathway enrichment. Enriched gene ontology and Kyoto Encyclopedia of Genes and Genomes pathway analysis showed that the DEPs were most strongly associated with "response to stress" and "protein processing in endoplasmic reticulum". Furthermore, several heat shock proteins were identified as DEPs. CONCLUSIONS: This information provides a reference direction for further research on the okra proteome in the downstream of the salt stress response, with our data revealing that the responses of okra to salt stress involves by various pathways.


Assuntos
Abelmoschus/metabolismo , Biologia Computacional/métodos , Proteínas de Plantas/metabolismo , Proteômica/métodos , Estresse Salino , Plântula/metabolismo , Abelmoschus/crescimento & desenvolvimento , Mapas de Interação de Proteínas , Plântula/crescimento & desenvolvimento
18.
Environ Pollut ; 251: 45-55, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31071632

RESUMO

Hydrogen gas (H2) has been shown as an important factor in plant tolerance to abiotic stresses, but the underlying mechanisms remain unclear. In the present study, the effects of H2 and its interaction with nitric oxide (NO) on alleviating cadmium (Cd) stress in Brassica campestris seedlings were investigated. NO donor (SNP) or hydrogen-rich water (HRW) treatment showed a significant improvement in growth of Cd-stressed seedlings. Cd treatment upregulated both endogenous NO and H2 (36% and 66%, respectively), and the increase of H2 was prior to NO increase. When treated with NO scavenger (PTIO) or NO biosynthesis enzyme inhibitors (L-NAME and Gln), HRW-induced alleviation under Cd stress was prevented. Under Cd stress, HRW pretreatment significantly enhanced the NO accumulation, and together up-regulated the activity of NR (nitrate reductase) and expression of NR. HRW induced lower reactive oxygen species (ROS), higher AsA content, enhanced activity of POD (peroxidase) and SOD (superoxide dismutase) in seedling roots were inhibited by PTIO, L-NAME and Gln. Through proteomic analysis, the level of 29 proteins were changed in response to H2 and NO-induced amelioration of Cd stress. Nearly half of them were involved in oxidation-reduction processes (about 20%) or antioxidant enzymes (approximately 20%). These results strongly indicate that in Cd-stressed seedlings, pretreatment with HRW induces the accumulation of H2 (biosynthesized or permeated), which further stimulates the biosynthesis of NO through the NR pathway. Finally, H2 and NO together enhance the antioxidant capabilities of seedlings in response to Cd toxicity.


Assuntos
Antioxidantes/metabolismo , Brassica/efeitos dos fármacos , Cádmio/toxicidade , Hidrogênio/farmacologia , Óxido Nítrico/biossíntese , Poluentes do Solo/toxicidade , Brassica/enzimologia , Brassica/metabolismo , Cádmio/metabolismo , Doadores de Óxido Nítrico/farmacologia , Oxirredução , Proteômica , Plântula/efeitos dos fármacos , Plântula/enzimologia , Plântula/metabolismo , Poluentes do Solo/metabolismo , Regulação para Cima/efeitos dos fármacos
19.
Plant Cell Physiol ; 60(8): 1790-1803, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31111914

RESUMO

The elucidation of epigenetic responses of salt-responsive genes facilitates understanding of the underlying mechanisms that confer salt tolerance in rice. However, it is still largely unknown how epigenetic mechanisms are associated with the expression of salt-responsive genes in rice and other crops. In this study, we reported tissue-specific gene expression and tissue-specific changes in chromatin modifications or signatures between seedlings and roots in response to salt treatment. Our study indicated that among six of individual mark examined (H3K4me3, H3K27me3, H4K12ac, H3K9ac, H3K27ac and H3K36me3), a positive association between salt-related changes in histone marks and the expression of differentially expressed genes (DEGs) was observed only for H3K9ac and H4K12ac in seedlings and H3K36me3 in roots. In contrast, chromatin states (CSs) with combinations of six histone modification marks played crucial roles in the differential expression of salt-responsive genes between seedlings and roots. Most importantly, CS7 containing the bivalent marks H3K4me3 and H3K27me3, with a mutual exclusion of functions with each other, displayed distinct functions in the expression of DEGs in both tissues. Specifically, H3K27me3 in CS7 mainly suppressed the expression of DEGs in roots, while H3K4me3 affected the expression of down- and up-regulated genes, possibly by antagonizing the repressive role of H3K27me3 in seedlings. Our findings indicate distinct impacts of the CSs on the differential expression of salt-responsive genes between seedlings and roots in rice, which provides an important background for understanding chromatin-based epigenetic mechanisms that might confer salt tolerance in plants.


Assuntos
Cromatina/metabolismo , Oryza/metabolismo , Raízes de Plantas/metabolismo , Plântula/metabolismo , Divisão Celular/genética , Divisão Celular/fisiologia , Regulação da Expressão Gênica de Plantas , Oryza/genética , Peroxirredoxinas/genética , Peroxirredoxinas/metabolismo , Fotossíntese/genética , Fotossíntese/fisiologia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Raízes de Plantas/genética , Plântula/genética
20.
Ecotoxicol Environ Saf ; 180: 656-667, 2019 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-31136876

RESUMO

Owing to the active use of rare-earth elements in many areas, it is necessary to study their behavior in the environment and their biological impact on plants. Despite the role of melatonin and sulfur in plant growth, development and abiotic stress tolerance; it is still not clear how they have a strong regulatory influence and synergistic effect on growth, physiological and biochemical characteristics of plants under different environmental stresses. Therefore, this study highlights how melatonin and sulfur together potentially involved in a reversal of lanthanum-inhibited photosynthetic and growth responses in tomato seedlings. Here, we reported that seedlings grown in a medium containing 150 µM lanthanum exhibited increased overproduction of reactive oxygen species (ROS) and lipid peroxidation together with increased Chlorophyll degradation, and activity of chlorophyllase, proline dehydrogenase and glycolate oxidase (GOx), and decreased photosynthesis and growth. However, the application of melatonin and sulfur showed significant responses on tomato seedlings, although the response of their combined treatment was more effective by further increasing photosynthesis and growth under lanthanum toxicity. Melatonin supplied with sulfur suppressed ROS formation, lipid peroxidation and activity of GOx, and increased photosynthesis by upregulating activities of carbonic anhydrase and ribulose-1,5-bisphosphate carboxylase/oxygenase. Also, sulfur supplementation with melatonin to seedlings resulted in an elevation in the accumulation of Chl and proline by increasing δ-aminolevulinic acid and activity of δ-aminolevulinic acid dehydratase and Δ1-pyrroline-5-carboxylate synthetase activity. The administration of melatonin with sulfur substantially induced upregulation of enzymes (superoxide dismutase, ascorbate peroxidase, monodehydroascorbate reductase, dehydroascorbate reductase and glutathione reductase) activities involved in the antioxidant system, thereby mitigating ROS-induced oxidative damage. Thus, this study provides strong evidence that melatonin and sulfur have strong regulatory influence and synergistic role in alleviating the adverse effect of lanthanum-toxicity by increasing photosynthesis and growth.


Assuntos
Poluentes Ambientais/toxicidade , Lantânio/toxicidade , Lycopersicon esculentum/efeitos dos fármacos , Melatonina/farmacologia , Enxofre/farmacologia , Antioxidantes/metabolismo , Peroxidação de Lipídeos/efeitos dos fármacos , Lycopersicon esculentum/crescimento & desenvolvimento , Lycopersicon esculentum/metabolismo , Fotossíntese/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Plântula/efeitos dos fármacos , Plântula/crescimento & desenvolvimento , Plântula/metabolismo
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