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1.
Ecotoxicol Environ Saf ; 209: 111761, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33333341

RESUMO

Cobalt (Co) and copper (Cu) co-exist commonly in the contaminated soils and at excessive levels, they are toxic to plants. However, their joint effect and possible interaction have not been fully addressed. In this work, a hydroponic experiment was performed to investigate the combined effects of Co and Cu on two barley genotypes at transcriptional level by RNA-seq analysis. The results identified 358 genes inclusively expressed in both genotypes under single and combined treatments of Co and Cu, with most of them being related to metal transport, stress response and transcription factor. The combined treatment induced more differently expressed genes (DEGs) than the single treatment, with Yan66, a metal tolerant genotype having more DEGs than Ea52, a sensitive genotype. The pathways associated with anthocyanin biosynthesis, MAPK signaling, glutathione biosynthesis, phenylalanine metabolism, photosynthesis, arginin biosynthesis, fatty acid elongation, and plant hormone signal transduction biosynthesis were induced and inhibited in Yan66 and Ea52, respectively. Furthermore, flavonoid biosynthesis was much more largely enhanced and accordingly more free flavonoid components (naringin, narirutin and neohesperidin) were accumulated in Yan66 than in Ea52. It may be suggested that high tolerance to both Co and Cu in Yan66 is attributed to its high gene regulatory ability.


Assuntos
Cobalto/toxicidade , Cobre/metabolismo , Hordeum/fisiologia , Adaptação Fisiológica/fisiologia , Cobalto/metabolismo , Cobre/toxicidade , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Genótipo , Hordeum/efeitos dos fármacos , Hordeum/genética , Hidroponia , Fotossíntese/efeitos dos fármacos , Reguladores de Crescimento de Planta/metabolismo , Estresse Fisiológico , Fatores de Transcrição/genética , Transcriptoma
2.
Nat Commun ; 11(1): 5138, 2020 10 12.
Artigo em Inglês | MEDLINE | ID: mdl-33046693

RESUMO

Grasses have varying inflorescence shapes; however, little is known about the genetic mechanisms specifying such shapes among tribes. Here, we identify the grass-specific TCP transcription factor COMPOSITUM 1 (COM1) expressing in inflorescence meristematic boundaries of different grasses. COM1 specifies branch-inhibition in barley (Triticeae) versus branch-formation in non-Triticeae grasses. Analyses of cell size, cell walls and transcripts reveal barley COM1 regulates cell growth, thereby affecting cell wall properties and signaling specifically in meristematic boundaries to establish identity of adjacent meristems. COM1 acts upstream of the boundary gene Liguleless1 and confers meristem identity partially independent of the COM2 pathway. Furthermore, COM1 is subject to purifying natural selection, thereby contributing to specification of the spike inflorescence shape. This meristem identity pathway has conceptual implications for both inflorescence evolution and molecular breeding in Triticeae.


Assuntos
Hordeum/metabolismo , Inflorescência/crescimento & desenvolvimento , Meristema/metabolismo , Proteínas de Plantas/metabolismo , Regulação da Expressão Gênica de Plantas , Hordeum/genética , Hordeum/crescimento & desenvolvimento , Inflorescência/genética , Inflorescência/metabolismo , Meristema/genética , Meristema/crescimento & desenvolvimento , Proteínas de Plantas/genética , Transdução de Sinais
3.
PLoS One ; 15(8): e0237834, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32853269

RESUMO

Water deficit is one of the major limitations to food production worldwide and most climate change scenarios predict an aggravation of the situation. To face the expected increase in drought stress in the coming years, breeders are working to elucidate the genetic control of barley growth and productivity traits under water deficit. Barley is known as a relatively drought tolerant crop and genetic variability was observed for drought tolerance traits. The objectives of the present study were the quantification of morphological and physiological responses in a collection of 209 spring barley genotypes to drought stress, and the genetic analysis by genome-wide association study to find quantitative trait loci (QTL) and the allele contributions for each of the investigated traits. In six pot experiments, 209 spring barley genotypes were grown under a well-watered and water-limited regime. Stress phases were initiated individually for each genotype at the beginning of tillering and spiking for the vegetative- and the generative stage experiments, respectively, and terminated when the transpiration rates of stress treatments reached 10% of the well-watered control. After the stress phase, a total of 42 productivity related traits such as the dry matter of plant organs, tiller number, leaf length, leaf area, amount of water soluble carbohydrates in the stems, proline content in leaves and osmotic adjustment of corresponding well-watered and stressed plants were analysed, and QTL analyses were performed to find marker-trait associations. Significant water deficit effects were observed for almost all traits and significant genotype x treatment interactions (GxT) were observed for 37 phenotypic traits. Genome-wide association studies (GWAS) revealed 77 significant loci associated with 16 phenotypic traits during the vegetative stage experiment and a total of 85 significant loci associated with 13 phenotypic traits during the generative stage experiment for traits such as leaf area, number of green leaves, grain yield, harvest index and stem length. For traits with significant GxT interactions, genotypic differences for relative values were analysed using one way ANOVA. More than 110 loci for GxT interaction were found for 17 phenotypic traits explaining in many cases more than 50% of the genetic variance.


Assuntos
Hordeum/genética , Hordeum/fisiologia , Locos de Características Quantitativas/genética , Estações do Ano , Água , Adaptação Fisiológica , Análise de Variância , Biomassa , Desidratação , Secas , Variação Genética , Genótipo , Hordeum/anatomia & histologia , Padrões de Herança/genética , Fenótipo , Análise de Regressão
4.
PLoS One ; 15(6): e0235475, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32603381

RESUMO

Sea barley Hordeum marinum is an important germplasm resource. However, the origin of this tetraploid H. marinum subsp. gussoneanum is still unclear, which has caused great perplexity to the exploration and utilization of germplasm resources. We used two single-copy nuclear genes, thioredoxin-like gene (TRX) and waxy1 gene encoding granule-bound starch synthase (WAXY1) to analyze 41 accessions of Hordeum marinum. The phylogenies of different genes told different story of evolution of tetraploids of H. marinum subsp. gussoneanum. The phylogenetic trees showed that two distinct copies of sequences from both genes were detected for some accessions of the tetraploids of H. marinum subsp. gussoneanum, and diploid marinum might also contribute to the origin and evolution of the tetraploid gussoneanum. Our findings suggested that tetraploid more likely originated from the diploids of H. marinum subsp. gussoneanum and another ancestor that might be an extinct unknown diploid species. Homogenization of gene in tetraploids also occurred after polyploidization as both TRX and WAXY1 sequences in some accessions of tetraploid H. marinum subsp. gussoneanum cannot be distinguished, indicating the complicated evolution of this tetraploid.


Assuntos
Hordeum/genética , Filogenia , Evolução Biológica , Genes de Plantas , Genoma de Planta , Poliploidia , Sintase do Amido/genética , Tetraploidia , Tiorredoxinas/genética
5.
PLoS One ; 15(7): e0235565, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32614894

RESUMO

Powdery mildew is an important foliar disease of barley (Hordeum vulgare L.) caused by the biotrophic fungus Blumeria graminis f. sp. hordei (Bgh). The understanding of the resistance mechanism is essential for future resistance breeding. In particular, the identification of race-nonspecific resistance genes is important because of their regarded durability and broad-spectrum activity. We assessed the severity of powdery mildew infection on detached seedling leaves of 267 barley accessions using two poly-virulent isolates and performed a genome-wide association study exploiting 201 of these accessions. Two-hundred and fourteen markers, located on six barley chromosomes are associated with potential race-nonspecific Bgh resistance or susceptibility. Initial steps for the functional validation of four promising candidates were performed based on phenotype and transcription data. Specific candidate alleles were analyzed via transient gene silencing as well as transient overexpression. Microarray data of the four selected candidates indicate differential regulation of the transcription in response to Bgh infection. Based on our results, all four candidate genes seem to be involved in the responses to powdery mildew attack. In particular, the transient overexpression of specific alleles of two candidate genes, a potential arabinogalactan protein and the barley homolog of Arabidopsis thaliana's Light-Response Bric-a-Brac/-Tramtrack/-Broad Complex/-POxvirus and Zinc finger (AtLRB1) or AtLRB2, were top candidates of novel powdery mildew susceptibility genes.


Assuntos
Ascomicetos/genética , Hordeum/genética , Interações Hospedeiro-Patógeno/genética , Doenças das Plantas/microbiologia , Alelos , Ascomicetos/isolamento & purificação , Ascomicetos/patogenicidade , Análise por Conglomerados , Regulação da Expressão Gênica de Plantas , Predisposição Genética para Doença , Estudo de Associação Genômica Ampla , Genótipo , Desequilíbrio de Ligação , Mucoproteínas/genética , Mucoproteínas/metabolismo , Fenótipo , Doenças das Plantas/genética , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plântula/genética , Virulência/genética
6.
PLoS One ; 15(7): e0236037, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32701981

RESUMO

Soil salinity imposes an agricultural and economic burden that may be alleviated by identifying the components of salinity tolerance in barley, a major crop and the most salt tolerant cereal. To improve our understanding of these components, we evaluated a diversity panel of 377 two-row spring barley cultivars during both the vegetative, in a controlled environment, and the reproductive stages, in the field. In the controlled environment, a high-throughput phenotyping platform was used to assess the growth-related traits under both control and saline conditions. In the field, the agronomic traits were measured from plots irrigated with either fresh or saline water. Association mapping for the different components of salinity tolerance enabled us to detect previously known associations, such as HvHKT1;5. Using an "interaction model", which took into account the interaction between treatment (control and salt) and genetic markers, we identified several loci associated with yield components related to salinity tolerance. We also observed that the two developmental stages did not share genetic regions associated with the components of salinity tolerance, suggesting that different mechanisms play distinct roles throughout the barley life cycle. Our association analysis revealed that genetically defined regions containing known flowering genes (Vrn-H3, Vrn-H1, and HvNAM-1) were responsive to salt stress. We identified a salt-responsive locus (7H, 128.35 cM) that was associated with grain number per ear, and suggest a gene encoding a vacuolar H+-translocating pyrophosphatase, HVP1, as a candidate. We also found a new QTL on chromosome 3H (139.22 cM), which was significant for ear number per plant, and a locus on chromosome 2H (141.87 cM), previously identified using a nested association mapping population, which associated with a yield component and interacted with salinity stress. Our study is the first to evaluate a barley diversity panel for salinity stress under both controlled and field conditions, allowing us to identify contributions from new components of salinity tolerance which could be used for marker-assisted selection when breeding for marginal and saline regions.


Assuntos
Cromossomos de Plantas , Hordeum/genética , Tolerância ao Sal/genética , Flores/genética , Flores/metabolismo , Genótipo , Hordeum/crescimento & desenvolvimento , Hordeum/metabolismo , Pirofosfatase Inorgânica/genética , Fenótipo , Proteínas de Plantas/genética , Locos de Características Quantitativas , Solo/química
7.
PLoS One ; 15(6): e0234052, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32502173

RESUMO

Like other crop species, barley, the fourth most important crop worldwide, suffers from the genetic bottleneck effect, where further improvements in performance through classical breeding methods become difficult. Therefore, indirect selection methods are of great interest. Here, genomic prediction (GP) based on 33,005 SNP markers and, alternatively, metabolic prediction (MP) based on 128 metabolites with sampling at two different time points in one year, were applied to predict multi-year agronomic traits in the nested association mapping (NAM) population HEB-25. We found prediction abilities of up to 0.93 for plant height with SNP markers and of up to 0.61 for flowering time with metabolites. Interestingly, prediction abilities in GP increased after reducing the number of incorporated SNP markers. The estimated effects of GP and MP were highly concordant, indicating MP as an interesting alternative to GP, being able to reflect a stable genotype-specific metabolite profile. In MP, sampling at an early developmental stage outperformed sampling at a later stage. The results confirm the value of GP for future breeding. With MP, an interesting alternative was also applied successfully. However, based on our results, usage of MP alone cannot be recommended in barley. Nevertheless, MP can assist in unravelling physiological pathways for the expression of agronomically important traits.


Assuntos
Genoma de Planta , Hordeum/genética , Metaboloma , Teorema de Bayes , Mapeamento Cromossômico , Genótipo , Hordeum/metabolismo , Fenótipo , Polimorfismo de Nucleotídeo Único
8.
J Food Sci ; 85(6): 1725-1734, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32484938

RESUMO

The proximate composition, total phenolics, antioxidant activity, minerals, and trace elements were determined in 42 barley landraces in order to highlight their nutritional potential and promote their cultivation. Two-row barley landraces had a higher average content of starch, protein, total phenolic compounds, and iron, when compared with six-row ones that presented higher mean ash and fiber concentrations. Additionally, the six-row barley landraces with strongly pigmented grains had lower zinc and manganese and higher protein mean concentrations than the whitish or lightly pigmented barley landraces. Factor analysis and linear discriminant analysis were used to correctly differentiate samples according to type of barley (landrace or commercial) and number of rows. In general, all the parameters varied considerably among the barley landraces analyzed, but some barley landraces could be emphasized according to fiber, minerals, and phenolic antioxidants. There were important differences in the mean values in all the chemical parameters according to the island of origin of the barley grains. The application of linear discriminant analysis was also a useful tool to differentiate all the barley landraces with six rows according to the island of origin. PRACTICAL APPLICATION: Barley is a versatile cereal that can be used for human and animal feed, brewing, and as biodiesel. From the nutritional point of view, barley is rich in starch, protein, dietary fiber and minerals, as well as antioxidant compounds and vitamins. The landraces analyzed in this study have remained intact for the last 900 years, which gives opportunity to genome of these barley landraces to evolve some very specific traits. The physicochemical characterization of these local landraces carried out by us could be very useful as a source of new quality in breeding programs.


Assuntos
Hordeum/química , Minerais/análise , Sementes/química , Cruzamento , Fibras na Dieta/análise , Hordeum/classificação , Hordeum/genética , Proteínas de Plantas/análise , Espanha , Amido/análise
9.
Ann Bot ; 126(5): 929-942, 2020 10 06.
Artigo em Inglês | MEDLINE | ID: mdl-32575125

RESUMO

BACKGROUND AND AIMS: Vitamin E (tocochromanol) is a lipid-soluble antioxidant and an essential nutrient for human health. Among cereal crops, barley (Hordeum vulgare) contains a high level of vitamin E, which includes both tocopherols and tocotrienols. Although the vitamin E biosynthetic pathway has been characterized in dicots, such as Arabidopsis, which only accumulate tocopherols, knowledge regarding vitamin E biosynthesis in monocots is limited because of the lack of functional mutants. This study aimed to obtain gene knockout mutants to elucidate the genetic control of vitamin E composition in barley. METHODS: Targeted knockout mutations of HvHPT and HvHGGT in barley were created with CRISPR/Cas9-enabled genome editing. High-performance liquid chromatography (HPLC) was performed to analyse the content of tocochromanol isomers in transgene-free homozygous Hvhpt and Hvhggt mutants. KEY RESULTS: Mutagenesis efficiency among T0 regenerated plantlets was 50-65 % as a result of two simultaneously expressed guide RNAs targeting each gene; most of the mutations were stably inherited by the next generation. The transgene-free homozygous mutants of Hvhpt and Hvhggt exhibited decreased grain size and weight, and the HvHGGT mutation led to a shrunken phenotype and significantly lower total starch content in grains. HPLC analysis revealed that targeted mutation of HvHPT significantly reduced the content of both tocopherols and tocotrienols, whereas mutations in HvHGGT completely blocked tocotrienol biosynthesis in barley grains. Transient overexpression of an HvHPT homologue in tobacco leaves significantly increased the production of γ- and δ-tocopherols, which may partly explain why targeted mutation of HvHPT in barley grains did not eliminate tocopherol production. CONCLUSIONS: Our results functionally validated that HvHGGT is the only committed gene for the production of tocotrienols, whereas HvHPT is partly responsible for tocopherol biosynthesis in barley.


Assuntos
Hordeum , Tocotrienóis , Sistemas CRISPR-Cas/genética , Edição de Genes , Hordeum/genética , Humanos , Tocoferóis , Vitamina E
11.
PLoS One ; 15(5): e0232665, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32401769

RESUMO

Genomic selection has been extensively implemented in plant breeding schemes. Genomic selection incorporates dense genome-wide markers to predict the breeding values for important traits based on information from genotype and phenotype records on traits of interest in a reference population. To date, most relevant investigations have been performed using single trait genomic prediction models (STGP). However, records for several traits at once are usually documented for breeding lines in commercial breeding programs. By incorporating benefits from genetic characterizations of correlated phenotypes, multiple trait genomic prediction (MTGP) may be a useful tool for improving prediction accuracy in genetic evaluations. The objective of this study was to test whether the use of MTGP and including proper modeling of spatial effects can improve the prediction accuracy of breeding values in commercial barley and wheat breeding lines. We genotyped 1,317 spring barley and 1,325 winter wheat lines from a commercial breeding program with the Illumina 9K barley and 15K wheat SNP-chip (respectively) and phenotyped them across multiple years and locations. Results showed that the MTGP approach increased correlations between future performance and estimated breeding value of yields by 7% in barley and by 57% in wheat relative to using the STGP approach for each trait individually. Analyses combining genomic data, pedigree information, and proper modeling of spatial effects further increased the prediction accuracy by 4% in barley and 3% in wheat relative to the model using genomic relationships only. The prediction accuracy for yield in wheat and barley yield trait breeding, were improved by combining MTGP and spatial effects in the model.


Assuntos
Hordeum/genética , Melhoramento Vegetal/métodos , Triticum/genética , Interação Gene-Ambiente , Genoma de Planta , Genômica/métodos , Genótipo , Hordeum/crescimento & desenvolvimento , Modelos Genéticos , Fenótipo , Seleção Genética , Triticum/crescimento & desenvolvimento
12.
Sci Data ; 7(1): 139, 2020 05 08.
Artigo em Inglês | MEDLINE | ID: mdl-32385314

RESUMO

Hulless barley (Hordeum vulgare L. var. nudum) is a barley variety that has loose husk cover of the caryopses. Because of the ease in processing and edibility, hulless barley has been locally cultivated and used as human food. For example, in Tibetan Plateau, hulless barley is the staple food for human and essential livestock feed. Although the draft genome of hulless barley has been sequenced, the assembly remains fragmented. Here, we reported an improved high-quality assembly and annotation of the Tibetan hulless barley genome using more than 67X PacBio long-reads. The N50 contig length of the new assembly is at least more than 19 times larger than other available barley assemblies. The new genome assembly also showed high gene completeness and high collinearity of genome synteny with the previously reported barley genome. The new genome assembly and annotation will not only remove major hurdles in genetic analysis and breeding of hulless barley, but will also serve as a key resource for studying barley genomics and genetics.


Assuntos
Genoma de Planta , Hordeum/genética , Anotação de Sequência Molecular , Tibet
13.
Ann Bot ; 126(2): 301-313, 2020 07 24.
Artigo em Inglês | MEDLINE | ID: mdl-32361758

RESUMO

BACKGROUND AND AIMS: In addition to preventing water loss, plant cuticles must also regulate nutrient loss via leaching. The eceriferum mutants in Hordeum vulgare (barley) potentially influence these functions by altering epicuticular wax structure and composition. METHODS: Cultivar 'Bonus' and five of its cer mutants were grown under optimal conditions for vegetative growth and maturation, and nine traits were measured. Nutrient and water amounts going through the soil and the amount of simulated rain as deionized water, affecting phyllosphere humidity, delivered during either the vegetative or maturation phase, were varied. Cer leaf genes and three wilty (wlt) mutations were characterized for reaction to toluidine blue and the rate of non-stomatal water loss. KEY RESULTS: Vegetative phase rain on 'Bonus' significantly decreased kernel weight and numbers by 15-30 %, while in cer.j59 and .c36 decreases of up to 42 % occurred. Maturation phase findings corroborated those from the vegetative phase. Significant pleiotropic effects were identified: cer.j59 decreased culm and spike length and 1000-kernel weight, .c36 decreased kernel number and weight, .i16 decreased spike length and .e8 increased culm height. Excepting Cer.zv and .ym mutations, none of the other 27 Cer leaf genes or wlt mutations played significant roles, if any, in preventing water loss. Cer.zv and .ym mutants lost non-stomatal water 13.5 times faster than those of Cer.j, .yi, .ys and .zp and 18.3 times faster than those of four cultivars and the mutants tested here. CONCLUSIONS: Using yield to measure the net effect of phyllosphere humidity and wax crystal structure revealed that the former is far more important than the latter. The amenable experimental setup described here can be used to delve deeper. Significant pleiotropic effects were identified for mutations in four Cer genes, of which one is known to participate in wax biosynthesis. Twenty-seven Cer leaf genes and three wlt mutations have little if any effect on water loss.


Assuntos
Hordeum/genética , Ceras , Umidade , Fenótipo , Folhas de Planta/genética
14.
PLoS One ; 15(5): e0233077, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32442185

RESUMO

The molecular bases of aphid virulence to aphid crop plant resistance genes are poorly understood. The Russian wheat aphid, Diuraphis noxia, (Kurdjumov), and the greenbug, Schizaphis graminum (Rondani), are global pest of cereal crops. Each species damages barley, oat, rye and wheat, but S. graminum includes fescue, maize, rice and sorghum in its host range. This study was conducted to compare and contrast the transcriptomes of S. graminum biotype I and D. noxia biotype 1 when each ingested phloem from leaves of varieties of bread wheat, Triticum aestivum L., containing no aphid resistance (Dn0), resistance to D. noxia biotype 1 (Dn4), or resistance to both D. noxia biotype 1 and S. graminum biotype I (Dn7, wheat genotype 94M370). Gene ontology enrichments, k-means analysis and KEGG pathway analysis indicated that 94M370 plants containing the Dn7 D. noxia resistance gene from rye had stronger effects on the global transcriptional profiles of S. graminum and D. noxia relative to those fed Dn4 plants. S. graminum responds to ingestion of phloem sap from 94M370 plants by expression of unigenes coding for proteins involved in DNA and RNA repair, and delayed tissue and structural development. In contrast, D. noxia displays a completely different transcriptome after ingesting phloem sap from Dn4 or 94M370 plants, consisting of unigenes involved primarily in detoxification, nutrient acquisition and structural development. These variations in transcriptional responses of D. noxia and S. graminum suggest that the underlying evolutionary mechanism(s) of virulence in these aphids are likely species specific, even in cases of cross resistance.


Assuntos
Afídeos/fisiologia , Resistência à Doença , Perfilação da Expressão Gênica/métodos , Hordeum/genética , Proteínas de Insetos/genética , Ração Animal , Animais , Afídeos/classificação , Afídeos/genética , Regulação da Expressão Gênica , Ontologia Genética , Herbivoria , Sequenciamento de Nucleotídeos em Larga Escala , Folhas de Planta/genética , Proteínas de Plantas/genética , Análise de Sequência de RNA , Especificidade da Espécie
15.
J Food Sci ; 85(6): 1689-1698, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32458491

RESUMO

Three hulless barley varieties were grown under normal conditions during 2017/2018 and 2018/2019, to improve their agronomic yield, and to assess how the genotype influences ß-glucan contents, and its structural, thermal, rheological, and functional properties, as intended to be used in food applications. The extracted gums with hot water at 55 °C and pH 8.0, showed contents from 5.75% to 6.41% (w/w), and concentrations from 68.55% to 79.29% of ß-glucan, with some starch and protein impurities. The results of the agronomic trail indicated the highly significant (P ≤ 0.01) influence of the genotype on all studied characteristics, and on the ß-glucan contents (0.28** and 0.33** ) at both seasons. The morphology of the three gums was significantly different in the distribution and structure of networks. Peak intensities of the -OH and -CH groups and CH2 stretching were higher and wider in Giza129 and Giza131. ß-Glucan networks melt from 71.5 to 87.18 °C, and Giza131 exhibited the highest thermal stability. The aqueous dispersions (1%) of ß-glucan gums exhibited a non-Newtonian behavior, and Giza130 presented the highest significant (P ≤ 0.05) apparent viscosity (η) and foaming stability. Giza129 showed the highest significant water and fat binding capacities, whereas Giza131 showed the highest significant foaming capacity. ß-Glucan gums showed different potentials in food applications as fat replacers, stabilizers, thickeners, and foaming agents in food systems. This study suggests planting the proper barley variety in breeding and genetic improvement programs to supply the food industry with the expected ß-glucan content with consistent structural, thermal, rheological, and functional properties. PRACTICAL APPLICATION: ß-Glucans play an important technological role in processed foods. Little current information is available on ß-glucan contents, and its potentiality on food applications, as influenced by variability among hulless barley genotypes. Accordingly, knowledge of ß-glucan levels in barley varieties is a valuable attribute for both consumers and food processors, and it will create an opportunity for scientific cooperation between food technologist and breeders to identify the suitable barley varieties to be used in breeding programs, to obtain barley with required ß-glucan contents, targeted for specific end uses.


Assuntos
Hordeum/química , beta-Glucanas/química , Indústria Alimentícia , Genótipo , Hordeum/classificação , Hordeum/genética , Estrutura Molecular , Amido/análise , Viscosidade
16.
Ann Bot ; 126(3): 435-444, 2020 08 13.
Artigo em Inglês | MEDLINE | ID: mdl-32300777

RESUMO

BACKGROUND AND AIMS: Proteases are responsible for protein degradation during leaf senescence, allowing nutrients to be redirected to sink tissues. In a previous work, we reported that sulphur deficiency produced a delay in the leaf senescence of barley (Hordeum vulgare L.) plants, at both vegetative and reproductive stages. In this work, we analyse the effect of sulphur deficiency on the expression of several genes coding for proteases of different catalytic groups, which have been strongly associated with leaf senescence. METHODS: Four independent experiments were performed in order to impose low sulphur availability conditions: one of steady-state sulphur deficiency during the vegetative stage and three of sulphur starvation during vegetative and reproductive stages. KEY RESULTS: Sulphur deficiency inhibited or reduced the senescence-associated induction of seven of the eight proteases analysed. Their induction, as well as senescence and phloem amino acid remobilization, could be achieved with senescence inducers such as methyl-jasmonate (a hormonal stimulus) and darkness, but with different rates of induction dependent on each gene. Sulphur deficiency also exerted an opposite effect on the expression of two cysteine-protease genes (HvSAG12 and HvLEGU) as well as on one serine-protease gene (HvSUBT) according to leaf age and plant phenological stages. All three genes were induced in green leaves but were repressed in senescent leaves of sulphur-deficient plants at the vegetative stage. At the reproductive stage, both cysteine-proteases were only repressed in senescent leaves, while the serine-protease was induced in green and senescent leaves by sulphur deficiency. CONCLUSIONS: Our results highlight the relevance of adequate sulphur nutrition in order to ensure leaf senescence onset and induction of protease genes, which will consequently impact on grain protein composition and quality. In addition, our results provide evidence that leaf age, plant developmental stage and the nature of the stress modulate the sulphur responses.


Assuntos
Hordeum/genética , Proteínas de Plantas/genética , Regulação da Expressão Gênica de Plantas , Peptídeo Hidrolases , Folhas de Planta/genética , Enxofre
17.
Ann Bot ; 126(2): 289-300, 2020 07 24.
Artigo em Inglês | MEDLINE | ID: mdl-32333775

RESUMO

BACKGROUND AND AIMS: Manganese (Mn) deficiency in barley is a global problem. It is difficult to detect in the early stages of symptom development and is commonly pre-emptively corrected by Mn foliar sprays that can be costly. Landraces adapted to marginal lands around the world represent a genetic resource for potential sustainability traits including mineral use efficiency. This research aims to confirm novel Mn use efficiency traits from the Scottish landrace Bere and use an association mapping approach to identify genetic loci associated with the trait. METHODS: A hydroponic system was developed to identify and characterize the Mn deficiency tolerance traits in a collection of landraces, including a large number of Scottish Bere barleys, a group of six-rowed heritage landraces grown in the highlands and islands of Scotland. Measuring chlorophyll fluorescence, the effect of Mn deficiency was identified in the early stages of development. Genotypic data, generated using the 50k Illumina iSelect genotyping array, were coupled with the Mn phenotypic data to create a genome-wide association study (GWAS) identifying candidate loci associated with Mn use efficiency. KEY RESULTS: The Bere lines generally had good Mn use efficiency traits. Individual Bere lines showed large efficiencies, with some Bere lines recording almost double chlorophyll fluorescence readings in limited Mn conditions compared with the elite cultivar Scholar. The Mn-efficient Bere lines had increased accumulation of Mn in their shoot biomass compared with elite cultivars, which was highly correlated to the chlorophyll fluorescence. Several candidate genes were identified as being associated with Mn use efficiency in the GWAS. CONCLUSIONS: Several genomic regions for Mn use efficiency traits originating from the Bere lines were identified. Further examination and validation of these regions should be undertaken to identify candidate genes for future breeding for marginal lands.


Assuntos
Hordeum/genética , Manganês , Estudo de Associação Genômica Ampla , Fenótipo , Escócia
18.
Physiol Plant ; 170(1): 46-59, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32246464

RESUMO

Studying the drought-responsive transcriptome is of high interest as it can serve as a blueprint for stress adaptation strategies. Despite extensive studies in this area, there are still many details to be uncovered, such as the importance of each gene involved in the stress response as well as the relationship between these genes and the physiochemical processes governing stress tolerance. This study was designed to address such important details and to gain insights into molecular responses of barley (Hordeum vulgare L.) to drought stress. To that, we combined RNA-seq data analysis with field and greenhouse drought experiments in a systems biology approach. RNA-sequence analysis identified a total of 665 differentially expressed genes (DEGs) belonging to diverse functional categories. A gene network was derived from the DEGs, which comprised of a total of 131 nodes and 257 edges. Gene network topology analysis highlighted two programmed cell death (PCD) modulating genes, MC1 (metacaspase 1) and TSN1 (Tudor-SN 1), as important (hub) genes in the predicted network. Based on the field trial, a drought-tolerant and a drought-susceptible barley genotype was identified from eight tested cultivars. Identified genotypes exhibited different physiochemical characteristics, including proline content, chlorophyll concentration, percentage of electrolyte leakage and malondialdehyde content as well as expression profiles of MC1 and TSN1 genes. Machine learning and correspondence analysis revealed a significant relationship between drought tolerance and measured characteristics in the context of PCD. Our study provides new insights which bridge barley drought tolerance to PCD through MC1 and TSN1 pathway.


Assuntos
Secas , Hordeum/genética , Apoptose , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas , Estresse Fisiológico/genética
19.
BMC Plant Biol ; 20(1): 142, 2020 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-32252633

RESUMO

BACKGROUND: Reducing the dependence of crop production on chemical fertilizer with its associated costs, carbon footprint and other environmental problems is a challenge for agriculture. New solutions are required to solve this problem, and crop breeding for high nitrogen use efficiency or tolerance of low nitrogen availability has been widely considered to be a promising approach. However, the molecular mechanisms of high nitrogen use efficiency or low-nitrogen tolerance in crop plants are still to be elucidated, including the role of long non-coding RNAs (lncRNAs). RESULTS: In this study, we identified 498 lncRNAs in barley (Hordeum vulgare) landrace B968 (Liuzhutouzidamai), of which 487 were novel, and characterised 56 that were responsive to low-nitrogen stress. For functional analysis of differentially-expressed lncRNAs, the gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment of co-expressed and co-located protein-coding genes were analyzed, and interactions with annotated co-expressed protein coding genes or micro RNAs (miRNAs) were further predicted. Target mimicry prediction between differentially-expressed lncRNAs and miRNAs identified 40 putative target mimics of lncRNAs and 58 target miRNAs. Six differentially-expressed lncRNAs were further validated by qPCR, and one in particular showed consistent differential expression using both techniques. Expression levels of most of the lncRNAs were found to be very low, and this may be the reason for the apparent inconsistency between RNA-seq and qPCR data. CONCLUSIONS: The analysis of lncRNAs that are differentially-expressed under low-nitrogen stress, as well as their co-expressed or co-located protein coding genes and target mimics, could elucidate complex and hitherto uncharacterised mechanisms involved in the adaptation to low-nitrogen stress in barley and other crop plants.


Assuntos
Hordeum/genética , Nitrogênio/metabolismo , RNA Longo não Codificante/genética , Estresse Fisiológico/genética , Biologia Computacional , Perfilação da Expressão Gênica/métodos , Regulação da Expressão Gênica de Plantas , Ontologia Genética , Hordeum/metabolismo , MicroRNAs/genética , RNA de Plantas/genética , RNA-Seq , Plântula/genética , Plântula/metabolismo
20.
PLoS One ; 15(4): e0232056, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32324773

RESUMO

Nitrogen use efficiency (NUE) is the efficiency with which plants acquire and use nitrogen. Plants have high-affinity nitrate transport systems, which involve certain nitrate transporter (NRT) genes. However, limited data are available on the contribution of the NRT2/3 gene family in barley nitrate transport. In the present study, ten putative NRT2 and three putative NRT3 genes were identified using bioinformatics methods. All the HvNRT2/3 genes were located on chromosomes 3H, 5H, 6H or 7H. Remarkably, the presence of tandem repeats indicated that duplication events contributed to the expansion of the NRT2 gene family in barley. In addition, the HvNRT2/3 genes displayed various expression patterns at selected developmental stages and were induced in the roots by both low and high nitrogen levels. Furthermore, the overexpression of HvNRT2.1 improved the yield related traits in Arabidopsis. Taken together, the data generated in the present study will be useful for genome-wide analyses to determine the precise role of the HvNRT2/3 genes during barley development, with the ultimate goal of improving NUE and crop production.


Assuntos
Proteínas de Transporte de Ânions/genética , Proteínas de Transporte de Ânions/metabolismo , Biologia Computacional/métodos , Hordeum/crescimento & desenvolvimento , Mapeamento Cromossômico , Evolução Molecular , Duplicação Gênica , Regulação da Expressão Gênica no Desenvolvimento , Regulação da Expressão Gênica de Plantas , Hordeum/genética , Hordeum/metabolismo , Família Multigênica , Nitratos/metabolismo , Filogenia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Raízes de Plantas/genética , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/metabolismo , Sequências de Repetição em Tandem
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