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1.
BMC Plant Biol ; 19(1): 341, 2019 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-31382871

RESUMO

BACKGROUND: Barley is a low phosphorus (P) demand cereal crop. Tibetan wild barley, as a progenitor of cultivated barley, has revealed outstanding ability of tolerance to low-P stress. However, the underlying mechanisms of low-P adaption and the relevant genetic controlling are still unclear. RESULTS: We identified low-P tolerant barley lines in a doubled-haploid (DH) population derived from an elite Tibetan wild barley accession and a high-yield cultivar. The tolerant lines revealed greater root plasticity in the terms of lateral root length, compared to low-P sensitive lines, in response to low-P stress. By integrating the QTLs associated with root length and root transcriptomic profiling, candidate genes encoding isoflavone reductase, nitrate reductase, nitrate transporter and transcriptional factor MYB were identified. The differentially expressed genes (DEGs) involved the growth of lateral root, Pi transport within cells as well as from roots to shoots contributed to the differences between low-P tolerant line L138 and low-P sensitive lines L73 in their ability of P acquisition and utilization. CONCLUSIONS: The plasticity of root system is an important trait for barley to tolerate low-P stress. The low-P tolerance in the elite DH line derived from a cross of Tibetan wild barley and cultivated barley is characterized by enhanced growth of lateral root and Pi recycling within plants under low-P stress.


Assuntos
Hordeum/fisiologia , Fósforo/metabolismo , Raízes de Plantas/fisiologia , Adaptação Fisiológica , Perfilação da Expressão Gênica , Genes de Plantas/genética , Genes de Plantas/fisiologia , Hordeum/genética , Hordeum/crescimento & desenvolvimento , Hordeum/metabolismo , Fósforo/deficiência , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/metabolismo , Locos de Características Quantitativas/genética , Estresse Fisiológico
2.
Food Chem ; 298: 124973, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31261005

RESUMO

The aim of the present study was to explore the underlying mechanisms involved in anthocyanin biosynthesis in purple, blue, and white barley using quantitative proteomics analysis. We identified the differences in protein expression and related functions involved in anthocyanin biosynthesis in purple, blue, and white barley (named H, M, and L groups, respectively, based on their anthocyanin content) using TMT-liquid chromatography/mass spectroscopy-based proteomic methods. Totally, 297, 300, 254, and 1421 differentially expressed proteins (DEPs) were found in H vs. L, H vs. M, L vs. M, and H vs. L vs. M groups, respectively. Six clusters of proteins from the 1421 DEPs were mainly involved in carbon metabolism, amino acid and secondary metabolite biosynthesis, and metabolic pathways. Several proteins were validated using parallel reaction monitoring. The proteins involved in amino acid biosynthesis, carbon metabolism, metabolic pathways, and phenylpropanoid biosynthesis were responsible for the color differences in the three barley varieties.


Assuntos
Antocianinas/metabolismo , Hordeum/metabolismo , Proteínas de Plantas/análise , Proteínas de Plantas/metabolismo , Cromatografia Líquida , Pigmentação , Proteômica/métodos , Espectrometria de Massas em Tandem
3.
Food Chem ; 293: 32-40, 2019 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-31151618

RESUMO

Low alcohol hulless barley wine (HW) is a popular beverage among the highland areas in China. It is known to have several health benefits due to the presence of ß-glucan and antioxidant compounds. Therefore, the total ß-glucan content, total phenols and flavonoids of HW samples from the highland areas of Sichuan province and Tibet were determined in this study. The results indicated that HW is abundant in both ß-glucan (54-76 mg/L) and phenolic compounds (131-178 mg/L). Moreover, this study also investigated the flavor and aroma characteristics of HW samples. A total of forty six volatile aroma substances were identified by GC-MS. The HWs could be classified into three distinct groups in terms of the region of origin according to the results of PCA based on the GC-MS data. These findings provide a useful foundation for further study of the health benefits and the flavor characteristics of HW in highland areas.


Assuntos
Aromatizantes/análise , Hordeum/química , Fenóis/análise , Compostos Orgânicos Voláteis/análise , Vinho/análise , beta-Glucanas/análise , China , Cromatografia Gasosa-Espectrometria de Massas , Hordeum/metabolismo , Análise de Componente Principal , Paladar
4.
Plant Mol Biol ; 101(1-2): 41-61, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31183604

RESUMO

KEY MESSAGE: Several classes of transcription factors are involved in the activation of defensins. A new type of the transcription factor responsible for the regulation of wheat grain specific defensins was characterised in this work. HD-Zip class IV transcription factors constitute a family of multidomain proteins. A full-length cDNA of HD-Zip IV, designated TaGL7 was isolated from the developing grain of bread wheat, using a specific DNA sequence as bait in the Y1H screen. 3D models of TaGL7 HD complexed with DNA cis-elements rationalised differences that underlined accommodations of binding and non-binding DNA, while the START-like domain model predicted binding of lipidic molecules inside a concave hydrophobic cavity. The 3'-untranslated region of TaGL7 was used as a probe to isolate the genomic clone of TdGL7 from a BAC library prepared from durum wheat. The spatial and temporal activity of the TdGL7 promoter was tested in transgenic wheat, barley and rice. TdGL7 was expressed mostly in ovary at fertilisation and its promoter was active in a liquid endosperm during cellularisation and later in the endosperm transfer cells, aleurone, and starchy endosperm. The pattern of TdGL7 expression resembled that of genes that encode grain-specific lipid transfer proteins, particularly defensins. In addition, GL7 expression was upregulated by mechanical wounding, similarly to defensin genes. Co-bombardment of cultured wheat cells with TdGL7 driven by constitutive promoter and seven grain or root specific defensin promoters fused to GUS gene, revealed activation of four promoters. The data confirmed the previously proposed role of HD-Zip IV transcription factors in the regulation of genes that encode lipid transfer proteins involved in lipid transport and defence. The TdGL7 promoter could be used to engineer cereal grains with enhanced resistance to insects and fungal infections.


Assuntos
Defensinas/genética , Regulação da Expressão Gênica de Plantas , Fatores de Transcrição/genética , Triticum/genética , DNA Complementar/genética , Grão Comestível/genética , Grão Comestível/metabolismo , Genes Reporter , Hordeum/genética , Hordeum/metabolismo , Especificidade de Órgãos , Oryza/genética , Oryza/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas , Regiões Promotoras Genéticas/genética , Fatores de Transcrição/metabolismo , Triticum/metabolismo , Técnicas do Sistema de Duplo-Híbrido
5.
Food Chem ; 295: 138-146, 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31174742

RESUMO

This study investigates the impact of different gelatinization characteristics of small and large barley starch granules on their enzymatic hydrolysis and sugar production during mashing. Therefore, a barley malt suspension was consecutively incubated at 45, 62, 72 and 78 °C to monitor starch behavior and enzymatic starch hydrolysis and sugar production. The combination of microscopic and rapid visco analyses showed that small starch granules persisted longer in the system and were present non-gelatinized at temperatures higher than 62 °C. HPAEC-PAD analysis showed that 8% of the total amount of starch, predominantly small granules, gelatinized at temperatures between 62 °C and 78 °C. Due to their delayed gelatinization in this system, their enzymatic hydrolysis yielded relatively more dextrins compared to what was observed for large granules. It was concluded that small granules should be taken into account when optimizing enzymatic hydrolysis of barley starch, like in brewing, distilling or bio-ethanol production.


Assuntos
Hordeum/metabolismo , Amido/química , Açúcares/metabolismo , Varredura Diferencial de Calorimetria , Dextrinas/metabolismo , Enzimas/metabolismo , Hidrólise , Tamanho da Partícula , Amido/metabolismo , Temperatura Ambiente , Viscosidade
6.
Ecotoxicol Environ Saf ; 180: 756-761, 2019 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-31154200

RESUMO

Nitrated polycyclic aromatic hydrocarbons (Nitro-PAHs) as important organic pollutants are ubiquitous in the atmospheric environment, agricultural soils and aquatic environments to pose a severe polluting risk. However, little is known about the mechanism of Nitro-PAHs genotoxicity in plants. We analyzed seeds germination, seedlings growth, and toxicity mechanism following 1-Nitropyrene treatment in Hordeum vulgare. Our results reveal that 1-NP treatment could be an inhibited agent on seeds germination and growth of roots and shoots. Additionally, the reduction of mitotic index and the increasing frequency of micronucleus suggest that 1-NP may pose a potential risk of genotoxicity in the plant. We further clarify that O2- and H2O2 radicals contribute to 1-NP stimulation induced oxidative damage. Our study provides insights into the role of Nitro-PAHs exposure on growth processing toxicity and genotoxicity in plant and provided a useful reference for the surveillance and risk management of Nitro-PAHs in environments.


Assuntos
Hordeum/efeitos dos fármacos , Mutagênicos/toxicidade , Estresse Oxidativo/efeitos dos fármacos , Hidrocarbonetos Policíclicos Aromáticos/toxicidade , Poluentes do Solo/toxicidade , Radicais Livres/metabolismo , Germinação/efeitos dos fármacos , Hordeum/crescimento & desenvolvimento , Hordeum/metabolismo , Óxidos de Nitrogênio/toxicidade , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/crescimento & desenvolvimento , Pirenos/toxicidade
7.
Plant Sci ; 285: 151-164, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31203880

RESUMO

Enhancing the accumulation of essential mineral elements in cereal grains is of prime importance for combating human malnutrition. Biofortification by breeding holds great potential for improving nutrient accumulation in grains. However, conventional breeding approaches require element analysis of many grain samples, which causes high costs. Here we applied hyperspectral imaging to estimate the concentration of 15 grain elements (C, B, Ca, Cd, Cu, Fe, K, Mg, Mn, Mo, N, Na, P, S, Zn) in high-throughput in the wild barley nested association mapping (NAM) population HEB-25, comprising 1,420 BC1S3 lines derived from crossing 25 wild barley accessions with the cultivar 'Barke'. Nutrient concentrations varied largely with a multitude of lines having higher micronutrient concentration than 'Barke'. In a genome-wide association study (GWAS), we located 75 quantitative trait locus (QTL) hotspots, whereof many could be explained by major genes such as NO APICAL MERISTEM-1 (NAM-1) and PHOTOPERIOD 1 (Ppd-H1). The GWAS approach revealed exotic alleles that were able to increase grain element concentrations. Remarkably, a QTL linked to GIBBERELLIN 20 OXIDASE 2 (HvGA20ox2) significantly increased several grain elements without yield loss. We conclude that introgressing promising exotic alleles into elite breeding material can assist in improving the nutritional value of barley grains.


Assuntos
Grão Comestível/genética , Hordeum/genética , Produção Agrícola , Grão Comestível/crescimento & desenvolvimento , Estudo de Associação Genômica Ampla , Hordeum/crescimento & desenvolvimento , Hordeum/metabolismo , Valor Nutritivo/genética , Locos de Características Quantitativas/genética , Característica Quantitativa Herdável , Análise Espectral/métodos
8.
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
9.
Mol Plant Microbe Interact ; 32(10): 1303-1313, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31194615

RESUMO

Pipecolic acid (Pip) is an essential component of systemic acquired resistance, priming resistance in Arabidopsis thaliana against (hemi)biotrophic pathogens. Here, we studied the potential role of Pip in bacteria-induced systemic immunity in barley. Exudates of barley leaves infected with the systemic immunity-inducing pathogen Pseudomonas syringae pv. japonica induced immune responses in A. thaliana. The same leaf exudates contained elevated Pip levels compared with those of mock-treated barley leaves. Exogenous application of Pip induced resistance in barley against the hemibiotrophic bacterial pathogen Xanthomonas translucens pv. cerealis. Furthermore, both a systemic immunity-inducing infection and exogenous application of Pip enhanced the resistance of barley against the biotrophic powdery mildew pathogen Blumeria graminis f. sp. hordei. In contrast to a systemic immunity-inducing infection, Pip application did not influence lesion formation by a systemically applied inoculum of the necrotrophic fungus Pyrenophora teres. Nitric oxide (NO) levels in barley leaves increased after Pip application. Furthermore, X. translucens pv. cerealis induced the accumulation of superoxide anion radicals and this response was stronger in Pip-pretreated compared with mock-pretreated plants. Thus, the data suggest that Pip induces barley innate immune responses by triggering NO and priming reactive oxygen species accumulation.


Assuntos
Resistência à Doença , Hordeum , Óxido Nítrico , Ácidos Pipecólicos , Arabidopsis/microbiologia , Resistência à Doença/efeitos dos fármacos , Resistência à Doença/fisiologia , Hordeum/metabolismo , Hordeum/microbiologia , Ácidos Pipecólicos/metabolismo , Ácidos Pipecólicos/farmacologia , Doenças das Plantas/microbiologia , Pseudomonas syringae/fisiologia , Espécies Reativas de Oxigênio/metabolismo , Xanthomonas/fisiologia
10.
BMC Complement Altern Med ; 19(1): 143, 2019 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-31226979

RESUMO

BACKGROUND: Constipation, a common health problem, causes discomfort and affects the quality of life. This study intended to evaluate the potential laxative effect of triple fermented barley (Hordeum vulgare L.) extract (FBe), produced by saccharification, Saccharomyces cerevisiae, and Weissella cibaria, on loperamide (LP)-induced constipation in Sprague-Dawley (SD) rats, a well-established animal model of spastic constipation. METHODS: Spastic constipation was induced via oral treatment with LP (3 mg/kg) for 6 days 1 h before the administration of each test compound. Similarly, FBe (100, 200 and 300 mg/kg) was orally administered to rats once a day for 6 days. The changes in number, weight, and water content of fecal, motility ratio, colonic mucosa histology, and fecal mucous contents were recorded. The laxative properties of FBe were compared with those of a cathartic stimulant, sodium picosulfate. A total of 48 (8 rats in 6 groups) healthy male rats were selected and following 10 days of acclimatization. Fecal pellets were collected one day before administration of the first dose and starting from immediately after the fourth administration for a duration of 24 h. Charcoal transfer was conducted after the sixth and final administration of the test compounds. RESULTS: In the present study, oral administration of 100-300 mg/kg of FBe exhibited promising laxative properties including intestinal charcoal transit ratio, thicknesses and mucous producing goblet cells of colonic mucosa with decreases of fecal pellet numbers and mean diameters remained in the lumen of colon, mediated by increases in gastrointestinal motility. CONCLUSION: Therefore, FBe might act as a promising laxative agent and functional food ingredient to cure spastic constipation, with less toxicity observed at a dose of 100 mg/kg.


Assuntos
Constipação Intestinal/dietoterapia , Alimentos Fermentados/análise , Hordeum/microbiologia , Laxantes/metabolismo , Extratos Vegetais/metabolismo , Animais , Constipação Intestinal/induzido quimicamente , Alimentos Fermentados/microbiologia , Hordeum/química , Hordeum/metabolismo , Humanos , Laxantes/química , Loperamida/efeitos adversos , Masculino , Extratos Vegetais/química , Ratos , Ratos Sprague-Dawley , Saccharomyces cerevisiae/metabolismo , Weissella/metabolismo
11.
Ecotoxicol Environ Saf ; 180: 234-241, 2019 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-31096127

RESUMO

Cobalt (Co) commonly co-exists with copper (Cu) in natural soils, but the information about their combined effects on plants is poorly available. In this study, we hydroponically investigated the combined effects of Co and Cu on two barley genotypes differing in Co toxicity tolerance to reveal the interaction pattern of these two metals. The results showed that single treatment of Co or Cu at the dose of 100 µM led to a significant decrease of growth and photosynthetic rate, and a significant increase of lipid peroxidation, ROS radicals as well as anti-oxidative enzyme (SOD, CAT and GR) activities and glutathione content, with the extent of effect being less in Yan66 than Ea52. The combined treatment of Co and Cu alleviated the toxicity of both metals in comparison with each metal treatment alone, as reflected by improved growth and photosynthesis, and much slight oxidative stress. The alleviation of metal toxicity upon combined treatment is mainly attributed to a drastic reduction of Co uptake and its translocation from roots to shoots. It may be suggested that interaction of Co and Cu on their uptake and movement in plants is antagonistic.


Assuntos
Cobalto/toxicidade , Cobre/toxicidade , Hordeum/efeitos dos fármacos , Poluentes do Solo/toxicidade , Antioxidantes/metabolismo , Interações de Medicamentos , Glutationa/metabolismo , Hordeum/enzimologia , Hordeum/metabolismo , Peroxidação de Lipídeos , Estresse Oxidativo/efeitos dos fármacos , Fotossíntese/efeitos dos fármacos
12.
Plant Sci ; 283: 83-94, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31128718

RESUMO

The continuing growth of the human population creates an inevitable necessity for higher crop yields, which are mandatory for the supply with adequate amounts of food. However, increasing grain yield may lead to a reduction of grain quality, such as a decline in protein and mineral nutrient concentrations causing the so-called hidden hunger. To assess the interdependence between quantity and quality and to evaluate the biofortification potential of wild barley, we conducted field studies, examining the interplay between plant development, yield, and nutrient concentrations, using HEB-YIELD, a subset of the wild barley nested association mapping population HEB-25. A huge variation of nutrient concentration in grains was obtained, since we identified lines with a more than 50% higher grain protein, iron, and zinc concentration in comparison to the recurrent parent 'Barke'. We observed a negative relationship between grain yield and nutritional value in barley, indicated by predominantly negative correlations between yield and nutrient concentrations. Analyzing the genetic control of nutrient concentration in mature grains indicated that numerous genomic regions determine the final nutritional value of grains and wild alleles were frequently associated with higher nutrient concentrations. The targeted introgression of wild barley alleles may enable biofortification in future barley breeding.


Assuntos
Biofortificação , Grão Comestível/metabolismo , Hordeum/metabolismo , Biofortificação/métodos , Cromossomos de Plantas/genética , Estudos de Associação Genética , Marcadores Genéticos , Hordeum/genética , Valor Nutritivo , Locos de Características Quantitativas
13.
Plant Cell Rep ; 38(8): 1013-1016, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31139893

RESUMO

KEY MESSAGE: The hormonal ratios along the barley spike regulate the development, atrophy and abortion of the spikelets and could be the mechanism by which the barley spike adapts its yield potential. Barley (Hordeum vulgare L.) is one of the oldest cereal crops known to be cultivated since about 10,000 years. The inflorescence of cultivated barley is an indeterminate spike that produces three single-flowered spikelets at each rachis node which make it unique among the grasses. The yield production in barley is predominantly controlled by very important parameters such as number of tillers and number of spikelets per spike. These two parameters are negatively correlated. Therefore, studying the biological and genetics of the spikelet development during the spike developmental stages is essential for breeding programs. Here we summarize our current understanding of the crosstalk between hormones such as auxin, cytokinin, gibberellin and abscisic acid along the spike and what is their role in regulating spike and spikelet development in barley. We conclude that the hormonal ratios at the apical, central, and basal sections of the spike not only regulate the spike developmental stages, but also the development, atrophy, and abortion of the spikelets. This hormonal dependent modification of the grain number along the spike could be the mechanism by which the barley spike adapts its yield potential.


Assuntos
Hordeum/metabolismo , Hordeum/fisiologia , Proteínas de Plantas/metabolismo , Ácido Abscísico/metabolismo , Regulação da Expressão Gênica de Plantas/fisiologia , Giberelinas/metabolismo , Ácidos Indolacéticos/metabolismo , Proteínas de Plantas/genética
14.
J Plant Physiol ; 238: 20-28, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31125706

RESUMO

The aim of this study was to observe the possible function of increased superoxide and NO production in the response of barley root tip to the harmful level of Cd. While superoxide generation was detected only in the transition zone, the formation of NO was observed in the apical elongation zones of the control root tips. However, the root region with the superoxide generation was also associated with peroxynitrite specific fluorescence signal. Superoxide, H2O2 and peroxynitrite generation increased with Cd treatment in a dose-dependent manner. In turn, NO level increased at low 10-20 µM but decreased at high 50-60 µM Cd concentrations in comparison with the control. While co-treatment of roots with rotenone markedly attenuated the Cd-induced superoxide generation and lipid peroxidation, it increased the level of NO in the root tips. Although rotenone did not influence the Cd-induced increase of GPX activity at 10-30 µM Cd concentrations, it markedly reversed the high 40-60 µM Cd concentrations-induced decline of GPX activity. Cd-induced cell death was associated with robust superoxide generation, but not with a high level of peroxynitrite. The Cd-evoked inhibition of root growth was significantly reversed by a strong antioxidant N-acetyl cysteine but not by a peroxynitrite scavenger uric acid, suggesting that similarly to Cd-induced cell death, an imbalance in the ROS homeostasis and not an enhanced level of peroxynitrite is responsible for the Cd-induced root growth inhibition. Based on these findings, it can be assumed that NO acts mainly in the regulation of superoxide level in the tips of root. Under Cd stress, the enhanced NO level is involved in the scavenging of highly toxic superoxide through the formation of peroxynitrite, thus reducing the superoxide-mediated cell death in barley root.


Assuntos
Cádmio/toxicidade , Hordeum/efeitos dos fármacos , Meristema/efeitos dos fármacos , Óxido Nítrico/metabolismo , Ácido Peroxinitroso/metabolismo , Superóxidos/metabolismo , Morte Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Hordeum/metabolismo , Peróxido de Hidrogênio/metabolismo , Peroxidação de Lipídeos/efeitos dos fármacos , Meristema/metabolismo , Espécies Reativas de Oxigênio/metabolismo
15.
J Plant Physiol ; 238: 29-39, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31129469

RESUMO

Control of gene expression and induction of cellular protection mechanisms are two important processes that plants employ to protect themselves against abiotic stresses. ABA-, stress, and ripening-induced (ASR) proteins have been identified to participate in such responses. Previous studies have proposed that these proteins can act as transcription factors and as molecular chaperones protecting transgenic plants against stresses; however a gene network regulated by ASRs has not been explored. To expand our knowledge on the function of these proteins in cereals, we present the functional characterization of a barley ASR gene. Expression of HvASR5 was almost ubiquitous in different organs and responded to ABA and to different stress treatments. When expressed ectopically, HvASR5 was able to confer drought and salt stress tolerance to Arabidopsis thaliana and to improve growth performance of rice plants under stress conditions. A transcriptomic analysis with two transgenic rice lines overexpressing HvASR5 helped to identify potential downstream targets and understand ASR-regulated cellular processes. HvASR5 up-regulated the expression of a distinct set of genes associated with stress responses, metabolic processes (particularly carbohydrate metabolism), as well as reproduction and development. These data, together with the confirmed nuclear and cytoplasmic localization of HvASR5, further support the hypothesis that HvASR5 can also carry out roles as molecular protector and transcriptional regulator.


Assuntos
Genes de Plantas/genética , Hordeum/genética , Oryza/genética , Proteínas de Plantas/fisiologia , Clonagem Molecular , Perfilação da Expressão Gênica , Genes de Plantas/fisiologia , Hordeum/metabolismo , Hordeum/fisiologia , Oryza/metabolismo , Oryza/fisiologia , Filogenia , Proteínas de Plantas/genética , Plantas Geneticamente Modificadas , Análise de Sequência de DNA , Estresse Fisiológico
16.
J Agric Food Chem ; 67(22): 6324-6335, 2019 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-31083935

RESUMO

This study was conducted to evaluate the effect of growth conditions and genotype on the barley yield and ß-glucan content of grain and malt. Total and water-extractable (W-E) ß-glucans and their molecular and structural properties were analyzed in nine 2-row barley varieties and corresponding malts. The total ß-glucan content of barley is not influenced by year or by the cultivar, while the grain yield and W-E ß-glucan content are significantly influenced by the year. Barley W-E ß-glucans have a molecular weight between 1.0 × 105 and 4.0 × 105 Da and a random coil conformation. ß-Glucan levels in malt are significantly lower than in barley, and neither the total nor the W-E ß-glucans are influenced by environmental factors or genetic aspects. W-E ß-glucans are mainly composed of fractions with Mw values below 1.0 × 105 Da. In conclusion, the molecular characterization of ß-glucans could represent a powerful tool to understand their role in the brewing process.


Assuntos
Hordeum/crescimento & desenvolvimento , beta-Glucanas/química , Manipulação de Alimentos , Genótipo , Hordeum/química , Hordeum/genética , Hordeum/metabolismo , Sementes/química , Sementes/genética , Sementes/crescimento & desenvolvimento , Sementes/metabolismo , beta-Glucanas/metabolismo
17.
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
18.
Plant Physiol Biochem ; 140: 18-26, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31078052

RESUMO

Arabidopsis thaliana cyclic nucleotide-gated ion channel gene 4 (AtCNGC4) loss-of-function mutant dnd2 exhibits elevated accumulation of salicylic acid (SA), dwarfed morphology, reduced hypersensitive response (HR), altered disease resistance and spontaneous lesions on plant leaves. An orthologous barley mutant, nec1, has been reported to over-accumulate indole-3-acetic acid (IAA) and to exhibit changes in stomatal regulation in response to exogenous auxin. Here we show that the Arabidopsis dnd2 over-accumulates both IAA and abscisic acid (ABA) and displays related phenotypic and physiological changes, such as, reduced stomatal size, higher stomatal density and stomatal index. dnd2 showed increased salt tolerance in root growth assay and significantly reduced stomatal conductance, while maintaining near wt reaction in stomatal conductance upon external application of ABA, and probably consequently increased drought stress tolerance. Introduction of both sid2-1 and fmo1 into dnd2 background resulting in removal of SA did not alter stomatal conductance. Hence, the closed stomata of dnd2 is probably a result of increased ABA levels and not increased SA levels. The triple dnd2sid2abi1-1 mutant exhibited intermediate stomatal conductance compared to dnd2 and abi1-1 (ABA insensitive, open stomata), while the response to external ABA was as in abi1-1 suggesting that reduced stomatal conductance in dnd2 is not due to impaired ABA signaling. In conclusion, Arabidopsis dnd2 mutant exhibited ABA overaccumulation and stomatal phenotypes, which may contribute to the observed improvement in drought stress resistance. Thus, Arabidopsis dnd2 mutant may serve as a model for studying crosstalk between biotic and abiotic stress and hormonal response in plants.


Assuntos
Ácido Abscísico/metabolismo , Proteínas de Arabidopsis/metabolismo , Arabidopsis/genética , Arabidopsis/metabolismo , Ácidos Indolacéticos/metabolismo , Estômatos de Plantas/metabolismo , Proteínas de Arabidopsis/genética , Secas , Regulação da Expressão Gênica de Plantas/genética , Regulação da Expressão Gênica de Plantas/fisiologia , Hordeum/genética , Hordeum/metabolismo , Estômatos de Plantas/genética
19.
Int J Mol Sci ; 20(7)2019 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-30965578

RESUMO

The identification of gene(s) that are involved in Cd accumulation/tolerance is vital in developing crop cultivars with low Cd accumulation. We developed a doubled haploid (DH) population that was derived from a cross of Suyinmai 2 (Cd-sensitive) × Weisuobuzhi (Cd-tolerant) to conduct quantitative trait loci (QTL) mapping studies. We assessed chlorophyll content, traits that are associated with development, metal concentration, and antioxidative enzyme activity in DH population lines and parents under control and Cd stress conditions. A single QTL, designated as qShCd7H, was identified on chromosome 7H that was linked to shoot Cd concentration; qShCd7H explained 17% of the phenotypic variation. Comparative genomics, map-based cloning, and gene silencing were used in isolation, cloning, and functional characterization of the candidate gene. A novel gene HvPAA1, being related to shoot Cd concentration, was identified from qShCd7H. Sequence comparison indicated that HvPAA1 carried seven domains with an N-glycosylation motif. HvPAA1 is predominantly expressed in shoots. Subcellular localization verified that HvPAA1 is located in plasma membrane. The silencing of HvPAA1 resulted in growth inhibition, greater Cd accumulation, and a significant decrease in Cd tolerance. We conclude HvPAA1 is a novel plasma membrane-localized ATPase that contributes to Cd tolerance and accumulation in barley. The results provide us with new insights that may aid in the screening and development of Cd-tolerant and low-Cd-accumulation crops.


Assuntos
Adenosina Trifosfatases/metabolismo , Cádmio/metabolismo , Hordeum/metabolismo , Adenosina Trifosfatases/genética , Cromossomos de Plantas/genética , Ligação Genética , Haploidia , Fenótipo , Locos de Características Quantitativas/genética
20.
J Sci Food Agric ; 99(11): 5176-5186, 2019 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-31021402

RESUMO

BACKGROUND: The literature on the role of calcium ion (Ca2+ ) in relation to phenolic compounds metabolism and related enzymes activities remains controversial. It is still unclear whether Ca2+ affects phenolic compounds content of barley sprouts. This study investigated the role and function of Ca2+ in phenolic compound metabolism of barley (Hordeum vulgare L.) sprouts under sodium chloride (NaCl) stress. RESULTS: Calcium chloride (CaCl2 ) significantly improved total calcium and calmodulin (CaM) contents as well as Ca2+ concentration, and enhanced phenolic compound accumulation by regulating the gene, protein expression and the activities of enzymes related to phenolics biosynthesis. Specifically, CaCl2 significantly increased the activities of phenylalanine ammonia lyase (PAL), cinnamic acid 4-hydroxylase (C4H), 4-coumarate coenzyme A ligase (4CL) and ferulic acid 5-hydroxylase (F5H) by up-regulating the corresponding protein expression. The activity of p-coumaric acid 3-hydroxylase (C3H) decreased during germination while caffeic acid O-methyltransferase (COMT) increased initially and then decreased, which was consistent with the changes in gene and protein expression under CaCl2 treatment. Conversely, lanthanum(III) chloride (LaCl3 ), ethylene glycol tetraacetic acid (EGTA) and 2-aminoethoxydiphenyl borate (2-APB) induced opposite effects. Decreased calcium and CaM contents and Ca2+ concentration were observed, and fluctuation change of relevant gene and protein expressions and PAL, C4H, 4CL, C3H, COMT and F5H activitives were also detected. CONCLUSION: Calcium ion played an important role for mediating NaCl stress-induced phenolics accumulation in barley sprouts. It required both Ca2+ influx and release from apoplast and intracellular stores, respectively. © 2019 Society of Chemical Industry.


Assuntos
Hordeum/metabolismo , Fenóis/metabolismo , Sementes/crescimento & desenvolvimento , Cloreto de Sódio/metabolismo , Cloreto de Cálcio/metabolismo , Coenzima A Ligases/metabolismo , Germinação , Hordeum/enzimologia , Hordeum/crescimento & desenvolvimento , Metiltransferases/metabolismo , Sementes/enzimologia , Sementes/metabolismo
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