Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 28.818
Filtrar
1.
J Environ Qual ; 49(3): 769-773, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-33016393

RESUMO

Closed-chamber methodology is widely used for the estimation of greenhouse gas (GHG) emissions in agricultural systems. The volume displaced by plants inside chambers influences GHG flux estimation, although generally it is not discounted from chamber headspace in the calculation. A novel image analysis-based procedure is proposed to estimate plant volume and to assess its impact on nitrous oxide (N2 O) flux estimations in a wheat (Triticum aestivum L. 'Rimbaud') crop. A maximum of 2.2% of the 13-L chambers was displaced by plants, leading to a systematic 0.9% overestimation in cumulative N2 O emissions if plant volume was not considered. Thus, plant canopy volume should be taken into account for improving the accuracy of emissions.


Assuntos
Gases de Efeito Estufa , Óxido Nitroso/análise , Agricultura , Triticum
2.
Plant Genome ; 13(1): e20011, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-33016629

RESUMO

Genome-wide association mapping identifies quantitative trait loci (QTL) that influence the mean differences between the marker genotypes for a given trait. While most loci influence the mean value of a trait, certain loci, known as variance heterogeneity QTL (vQTL) determine the variability of the trait instead of the mean trait value (mQTL). In the present study, we performed a variance heterogeneity genome-wide association study (vGWAS) for grain cadmium (Cd) concentration in bread wheat. We used double generalized linear model and hierarchical generalized linear model to identify vQTL associated with grain Cd. We identified novel vQTL regions on chromosomes 2A and 2B that contribute to the Cd variation and loci that affect both mean and variance heterogeneity (mvQTL) on chromosome 5A. In addition, our results demonstrated the presence of epistatic interactions between vQTL and mvQTL, which could explain variance heterogeneity. Overall, we provide novel insights into the genetic architecture of grain Cd concentration and report the first application of vGWAS in wheat. Moreover, our findings indicated that epistasis is an important mechanism underlying natural variation for grain Cd concentration.


Assuntos
Pão , Triticum , Cádmio , Estudo de Associação Genômica Ampla , Genômica , Triticum/genética
3.
J Environ Manage ; 263: 110365, 2020 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-32883473

RESUMO

Nanoparticles (NPs) application in soil as nano-fertilizers to increase crop yield is getting attention due to their higher efficiency and less environmental risks. This study investigated the interactive effects of variable titanium dioxide nanoparticles (TiO2-NPs) levels (0, 30, 50 and 100 mg kg-1) superimposed to phosphorus (P) fertilizer application in soil at the rates of 0, 25 and 50 mg kg-1 on wheat crop. Physiological parameters of plants, their antioxidant enzymes activities (SOD, POD), and contents of crude protein, H2O2, MDA and metals/nutrients (Al, Ca, Mg, Fe, Zn and Cu) were measured. Data on physiological traits revealed that application of 50 mg kg-1 of TiO2-NPs without P fertilizer significantly enhanced the root and shoot length by 63 and 26%, respectively. Increased contents of nutrients in the shoots, viz., Ca (316%), Cu (296%), Al (171%) and Mg (187%) with 50 mg kg-1 TiO2-NPs treatment reflected improvement in crop growth and grain quality. Furthermore, P contents in plant tissues were raised up to 56% with 50 mg kg-1 of TiO2-NPs even in the absence of P fertilizer. In the soil, concentration of phytoavailable P was significantly increased up to 63.3% in the presence of 50 mg kg-1 TiO2-NPs as compared to control. Contents of crude protein in grain were also enhanced by 22.8% (at P50) and 17.4% (at P25) with 50 mg kg-1 TiO2-NPs application. Along with P application, TiO2-NPs triggered the activities of SOD (2.06-33.97%) and POD (up to 13.19%), and H2O2 production (50.6-138.8%). However, MDA contents were not elevated significantly at any level of TiO2-NPs, and remained at par with control. It was noteworthy that highest level of TiO2-NPs, viz., 100 mg kg-1 exhibited plant and nutrients response lower than that with 50 mg kg-1. Further, TiO2-NPs triggered the bioavailability of micronutrient heavy metals (Zn, Cu and Fe) and Al, which could have toxicity at higher concentrations. These results suggested that TiO2-NPs might have some affinities with phosphate compounds and metal ions in the soil to bring them in soluble form, which enhanced their bioavailability. Although it improved the crop yield and quality, but toxic or negative impact of TiO2-NPs was also apparent at higher dose. Therefore, investigations on the potential interactions of NPs with other nutrients and toxic metals are needed to enhance our understanding for the safer application of nano-fertilizer.


Assuntos
Nanopartículas , Poluentes do Solo/análise , Peróxido de Hidrogênio , Fósforo , Solo , Titânio , Triticum
4.
Sci Total Environ ; 741: 140488, 2020 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-32887004

RESUMO

Nitrogen fertilization significantly increases greenhouse gases (GHGs) emission, when applied from inorganic or organic sources. Minimizing GHGs from agroecosystems without compromising crop yield for stabilization of green production systems remains a challenge. Being an integral component of wheat production technology, the nitrogen (N) application deems to be indispensable. Thus, to reduce the application of N fertilizer and keep in view the minimization of GHGs emission, without compromising soil fertility and wheat production, field experiments were performed with treatments included maize straw mulch (S1: 0, S2: 4500, S3: 9000 kg ha-1) and nitrogen fertilizer (N1: 0, N2: 192 and N3: 240 kg ha-1) during 2015-17. Results showed that the cumulative CO2 and N2O emission from 9000 kg ha-1 of maize straw mulch with 192 kg N ha-1 (S3N2) significantly decreased by 0.67% and 33.7%, respectively, averaged over two years compared with that of 9000 kg ha-1 of maize straw mulch with 240 kg N ha-1 (S3N3). Likewise, the average soil moisture content significantly increased by 10% and 10.6% for S3N2 and S3N3 treatments at 0-10 cm soil depth, respectively, compared to S1N1. Similarly, the S3N2 and S3N3 treatments had lowered the soil temperature by 0.2 and 0.1 °C, respectively, over S1N1 in wheat grown fields. The grain yield of wheat was increased by 45% and 45% under S3N3 and S3N2 treatments than S1N1, respectively. The S3N2 treatment was more economical than S3N3 for wheat crop. Therefore, maize straw mulch (S3) combined with 20% less N fertilizer (N2) from commercial source were considered as a viable production technology to improve crop yield, and reduce soil CO2 and N2O emissions.


Assuntos
Fertilizantes/análise , Triticum , Agricultura , Dióxido de Carbono , China , Nitrogênio/análise , Óxido Nitroso/análise , Solo , Zea mays
5.
PLoS One ; 15(8): e0236226, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32866160

RESUMO

Amine oxidases (AOs) including copper containing amine oxidases (CuAOs) and FAD-dependent polyamine oxidases (PAOs) are associated with polyamine catabolism in the peroxisome, apoplast and cytoplasm and play an essential role in growth and developmental processes and response to biotic and abiotic stresses. Here, we identified PAO genes in common wheat (Triticum aestivum), T. urartu and Aegilops tauschii and reported the genome organization, evolutionary features and expression profiles of the wheat PAO genes (TaPAO). Expression analysis using publicly available RNASeq data showed that TaPAO genes are expressed redundantly in various tissues and developmental stages. A large percentage of TaPAOs respond significantly to abiotic stresses, especially temperature (i.e. heat and cold stress). Some TaPAOs were also involved in response to other stresses such as powdery mildew, stripe rust and Fusarium infection. Overall, TaPAOs may have various functions in stress tolerances responses, and play vital roles in different tissues and developmental stages. Our results provided a reference for further functional investigation of TaPAO proteins.


Assuntos
Resposta ao Choque Frio/genética , Oxirredutases atuantes sobre Doadores de Grupo CH-NH/genética , Proteínas de Plantas/genética , Termotolerância/genética , Triticum/genética , Aegilops/enzimologia , Aegilops/genética , Processamento Alternativo , Sequência de Aminoácidos , Conjuntos de Dados como Assunto , Evolução Molecular , Perfilação da Expressão Gênica , Regulação da Expressão Gênica no Desenvolvimento , Regulação da Expressão Gênica de Plantas , Genes de Plantas , Genoma de Planta , Estudo de Associação Genômica Ampla , Cadeias de Markov , Modelos Genéticos , Peso Molecular , Família Multigênica , Oxirredutases atuantes sobre Doadores de Grupo CH-NH/química , Oxirredutases atuantes sobre Doadores de Grupo CH-NH/metabolismo , Filogenia , Proteínas de Plantas/química , Proteínas de Plantas/metabolismo , Domínios Proteicos/genética , RNA-Seq , Alinhamento de Sequência , Triticum/enzimologia
6.
PLoS One ; 15(8): e0236186, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32866164

RESUMO

AIM: To establish a gene co-expression network for identifying principal modules and hub genes that are associated with drought resistance mechanisms, analyzing their mechanisms, and exploring candidate genes. METHODS AND FINDINGS: 42 data sets including PRJNA380841 and PRJNA369686 were used to construct the co-expression network through weighted gene co-expression network analysis (WGCNA). A total of 1,896,897,901 (284.30 Gb) clean reads and 35,021 differentially expressed genes (DEGs) were obtained from 42 samples. Functional enrichment analysis indicated that photosynthesis, DNA replication, glycolysis/gluconeogenesis, starch and sucrose metabolism, arginine and proline metabolism, and cell cycle were significantly influenced by drought stress. Furthermore, the DEGs with similar expression patterns, detected by K-means clustering, were grouped into 29 clusters. Genes involved in the modules, such as dark turquoise, yellow, and brown, were found to be appreciably linked with drought resistance. Twelve central, greatly correlated genes in stage-specific modules were subsequently confirmed and validated at the transcription levels, including TraesCS7D01G417600.1 (PP2C), TraesCS5B01G565300.1 (ERF), TraesCS4A01G068200.1 (HSP), TraesCS2D01G033200.1 (HSP90), TraesCS6B01G425300.1 (RBD), TraesCS7A01G499200.1 (P450), TraesCS4A01G118400.1 (MYB), TraesCS2B01G415500.1 (STK), TraesCS1A01G129300.1 (MYB), TraesCS2D01G326900.1 (ALDH), TraesCS3D01G227400.1 (WRKY), and TraesCS3B01G144800.1 (GT). CONCLUSIONS: Analyzing the response of wheat to drought stress during different growth stages, we have detected three modules and 12 hub genes that are associated with drought resistance mechanisms, and five of those genes are newly identified for drought resistance. The references provided by these modules will promote the understanding of the drought-resistance mechanism. In addition, the candidate genes can be used as a basis of transgenic or molecular marker-assisted selection for improving the drought resistance and increasing the yields of wheat.


Assuntos
Aclimatação/genética , Regulação da Expressão Gênica de Plantas , Redes Reguladoras de Genes , Estresse Fisiológico/genética , Triticum/genética , China , Análise por Conglomerados , Conjuntos de Dados como Assunto , Secas , Perfilação da Expressão Gênica , Genes de Plantas , Melhoramento Vegetal/métodos , RNA-Seq , Seleção Genética
7.
Nat Commun ; 11(1): 4408, 2020 09 02.
Artigo em Inglês | MEDLINE | ID: mdl-32879311

RESUMO

Understanding extreme weather impacts on staple crops such as wheat is vital for creating adaptation strategies and increasing food security, especially in dryland cropping systems across Southern Africa. This study analyses heat impacts on wheat using daily weather information and a dryland wheat dataset for 71 cultivars across 17 locations in South Africa from 1998 to 2014. We estimate temperature impacts on yields in extensive regression models, finding that extreme heat drives wheat yield losses, with an additional 24 h of exposure to temperatures above 30 °C associated with a 12.5% yield reduction. Results from a uniform warming scenario of +1 °C show an average wheat yield reduction of 8.5%, which increases to 18.4% and 28.5% under +2 and +3 °C scenarios. We also find evidence of differences in heat effects across cultivars, which suggests warming impacts may be reduced through the sharing of gene pools amongst wheat breeding programs.


Assuntos
Adaptação Fisiológica , Produtos Agrícolas , Triticum , Cruzamento/métodos , Mudança Climática , Produtos Agrícolas/crescimento & desenvolvimento , Produtos Agrícolas/fisiologia , Genótipo , Aquecimento Global , Temperatura Alta , África do Sul , Triticum/genética , Triticum/crescimento & desenvolvimento , Triticum/fisiologia
8.
Pestic Biochem Physiol ; 170: 104696, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32980050

RESUMO

Combined application of plant essential oils (EOs) with known antimicrobial effects and silica nanocapsules with high loading capacity and protection capability of the EOs make them proper candidates for creating environmentally friendly fungicides. In this study, EOs of the Lemongrass (LGO) and Clove (CO) were used against Gaeumannomyces graminis var. tritici (Ggt), a causal agent of take-all disease of wheat. To provide controlled delivery of the EOs, they were encapsulated into mesoporous silica nanoparticles (MSNPs) and then compared to the effects of pure EOs both in- vitro and in- vivo. MSNPs were synthesized via the sol-gel process. Various techniques such as Fourier transform infrared spectroscopy (FTIR), the Brunauer-Emmett-Teller (BET), thermogravimetric analysis (TGA), and UV-Vis spectroscopy were used to evaluate the successful loading of the EOs into the pore of MSNPs. The encapsulation efficiency (EE) was calculated as high as 84.24% for LGO and 80.69% for CO, while loading efficiency (LE) was determined 36% and 29% for LGO and CO, respectively. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) displayed spherical shapes and porous structures with average diameters of 50-70 nm. Recognition of the main components of the EOs via gas chromatographic-mass spectrometry (GC-MS) before and after the EO loading, detected eugenol and citral as the most frequent compounds in LGO and CO, respectively. For antifungal test in- vitro, selected concentrations of the pure EOs, EOs loaded in MSNPs (EOs- MSNPs) and Mancozeb ® fungicide based on pre-tests were mixed using potato dextrose agar (PDA). The inhibition percentage (IP) of fungal growth at each concentration, as well as minimum inhibition concentration (MIC) and minimum fungicidal concentrations (MFC) were obtained. The results indicated that antifungal effects in the encapsulated form increased by up to three times. In- vivo, the sterile wheat seeds were treated with pure EOs, EOs-MSNPs, and mancozeb at MFC concentration. Also, in order to keep on the EOs-MSNPs around the seeds, sodium alginate was used. The consequences of in- vivo experiments indicated that rate of disease control in presence of EOs-MSNPs and mancozeb was the same (~70%) and higher than pure EOs (LGO: 57.44%, CO: 49%). Also, improving the growth parameters in wheat plant, the covering of the EOs-MSNPs in alginate, had better control (84%) than that of EOs-MSNPs alone. Further, the release kinetics studies showed a gradual release of LGO and CO from MSNPs for four weeks in water and for five weeks in the soil-plant system. To the best of our knowledge, this is the first report of the control effect of LGO, CO, and their nanocapsule in MSNPs against the take-all disease of wheat. These results showed that the EOs-MSNPs can be a safe product for the efficient control of take-all disease in wheat crop.


Assuntos
Cymbopogon , Nanopartículas , Óleos Voláteis/farmacologia , Antifúngicos/farmacologia , Óleo de Cravo/farmacologia , Dióxido de Silício , Triticum
9.
Yi Chuan ; 42(9): 916-925, 2020 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-32952125

RESUMO

Common wheat (T. aestivum L.) is also known as allohexaploid wheat. Its genome is composed of A/B/D sub-genomes from three closely related diploid ancestors. The evolutionary history of common wheat is used as a classic example to illustrate the mechanism of species formation and chromosome number variation in the current genetics class. In recent years, with the rapid development and application of research technologies, there have been many breakthroughs in the study of common wheat, at the cytological, molecular and genomic level. Here, we summarize the latest research achievements on common wheat, and discuss our practice in combining them with the genetics teaching. Our approach is not only a supplement to the current genetics textbooks, but also enables students to realize that genetics is a constantly evolving natural science. We aim to enhance students' interests in learning, as well as their systematic learning abilities on genetics and related scientific research frontiers.


Assuntos
Triticum , Evolução Biológica , Diploide , Genoma de Planta , Poliploidia , Ensino
10.
Nat Commun ; 11(1): 4382, 2020 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-32873802

RESUMO

Fusarium graminearum is a causal agent of Fusarium head blight (FHB) and a deoxynivalenol (DON) producer. In this study, OSP24 is identified as an important virulence factor in systematic characterization of the 50 orphan secreted protein (OSP) genes of F. graminearum. Although dispensable for growth and initial penetration, OSP24 is important for infectious growth in wheat rachis tissues. OSP24 is specifically expressed during pathogenesis and its transient expression suppresses BAX- or INF1-induced cell death. Osp24 is translocated into plant cells and two of its 8 cysteine-residues are required for its function. Wheat SNF1-related kinase TaSnRK1α is identified as an Osp24-interacting protein and shows to be important for FHB resistance in TaSnRK1α-overexpressing or silencing transgenic plants. Osp24 accelerates the degradation of TaSnRK1α by facilitating its association with the ubiquitin-26S proteasome. Interestingly, TaSnRK1α also interacts with TaFROG, an orphan wheat protein induced by DON. TaFROG competes against Osp24 for binding with the same region of TaSnRKα and protects it from degradation. Overexpression of TaFROG stabilizes TaSnRK1α and increases FHB resistance. Taken together, Osp24 functions as a cytoplasmic effector by competing against TaFROG for binding with TaSnRK1α, demonstrating the counteracting roles of orphan proteins of both host and fungal pathogens during their interactions.


Assuntos
Proteínas Fúngicas/metabolismo , Fusarium/patogenicidade , Doenças das Plantas/imunologia , Proteínas de Plantas/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Triticum/microbiologia , Fatores de Virulência/metabolismo , Resistência à Doença , Fusarium/imunologia , Fusarium/metabolismo , Interações Hospedeiro-Patógeno/imunologia , Doenças das Plantas/microbiologia , Proteínas de Plantas/genética , Proteínas de Plantas/imunologia , Plantas Geneticamente Modificadas , Complexo de Endopeptidases do Proteassoma/metabolismo , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/imunologia , Proteólise , Tricotecenos/metabolismo , Triticum/imunologia
11.
Nat Commun ; 11(1): 4876, 2020 09 25.
Artigo em Inglês | MEDLINE | ID: mdl-32978378

RESUMO

In most crops, genetic and environmental factors interact in complex ways giving rise to substantial genotype-by-environment interactions (G×E). We propose that computer simulations leveraging field trial data, DNA sequences, and historical weather records can be used to tackle the longstanding problem of predicting cultivars' future performances under largely uncertain weather conditions. We present a computer simulation platform that uses Monte Carlo methods to integrate uncertainty about future weather conditions and model parameters. We use extensive experimental wheat yield data (n = 25,841) to learn G×E patterns and validate, using left-trial-out cross-validation, the predictive performance of the model. Subsequently, we use the fitted model to generate circa 143 million grain yield data points for 28 wheat genotypes in 16 locations in France, over 16 years of historical weather records. The phenotypes generated by the simulation platform have multiple downstream uses; we illustrate this by predicting the distribution of expected yield at 448 cultivar-location combinations and performing means-stability analyses.


Assuntos
Simulação por Computador , Produtos Agrícolas/genética , Genótipo , Incerteza , Tempo (Meteorologia) , Agricultura/métodos , DNA de Plantas , Grão Comestível/genética , França , Interação Gene-Ambiente , Modelos Genéticos , Fenótipo , Triticum/genética
12.
Chemosphere ; 254: 126905, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32957298

RESUMO

With the development of modern technologies, the exploitation and application of rare earth metals (REMs) have increased parallelly. Consequently, more REMs are entering into the environment and therefore there is a pressing need to assess their potential environmental hazards. Here, a standard toxicity test with wheat (Triticum aestivum) was conducted to investigate the single and mixture toxicity of La and Ce in solutions with different levels of calcium and nitrilotriacetic acid (NTA) and results were deciphered by different modeling approaches. Both La and Ce caused adverse effect to wheat, but the presence of Ca and NTA alleviated their toxicity. The obtained EC50 for [La] or [Ce] changed by more than 28-fold and by 4-fold, respectively, with the increase of Ca or NTA. The biotic ligand model (BLM) explained approximately 93% variation of single La or Ce toxicity. The binding constants obtained were 4.14, 6.67, and 6.59 for logKCaBL, logKLaBL, and logKCeBL respectively. The electrostatic toxicity model (ETM) was proved as effective as the BLM, with R2 = 0.93 for La and R2 = 0.92 for Ce. For La-Ce mixtures, parameters from single toxicity approaches were applied successfully to predict the mixture toxicity with concentration addition (CA) model based on the BLM or ETM theory (R2 = 0.92 and RMSE = 8.56; R2 = 0.90 and RMSE = 9.6, respectively). Thus, the results obtained in this study prove that both ETM and BLM theories are appropriate to predict single and mixture REMs toxicity, providing coherent and promising tools for the risk assessment of REM pollution.


Assuntos
Cálcio/química , Cério/toxicidade , Lantânio/toxicidade , Ácido Nitrilotriacético/química , Testes de Toxicidade/métodos , Triticum/efeitos dos fármacos , Ligantes , Modelos Teóricos , Soluções , Eletricidade Estática , Triticum/crescimento & desenvolvimento
13.
Chemosphere ; 254: 126918, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32957302

RESUMO

The increasing application of various surfactants nowadays, may lead to the contamination of the natural environment and represent potential threat to terrestrial higher plants. In this article, the effect of 13 surfactants, with dodecyl alkyl chain and various aromatic (imidazolium, pyridinium, thiazolium) and aliphatic (guanidinium, ammonium, thiosemicarbazidium) polar heads, on germination, development and growth of wheat and cucumber was investigated. The study aimed to prove how changes in lipophilicity of surfactants and their various structural modifications (existence of the aliphatic or aromatic polar group, the introduction of oxygen and sulfur) influence toxicity towards investigated plants. The calculated lipophilic parameter (AlogP) is shown to be a useful parameter for predicting potential toxicity of the compound. The strategy of using surfactants with aliphatic polar heads instead of aromatic prove to be a promising strategy in reducing harmful effect, as well as the introduction of polar groups in the structure of cation. From all investigated compounds, surfactants with imidazolium polar head displayed the most harmful effect towards wheat and cucumber. The cucumber seeds were more sensitive to the addition of surfactants comparing to wheat. All obtained experimental results were additionally investigated using computational methods, simulating the transport of surfactants through a lipid bilayer. The influence of cation tendency to fit in lipid bilayer structure was correlated with toxicity. For the first time, it is concluded that cation ability to mimic the structure of bilayer have less harmful effect on plant development.


Assuntos
Cucumis sativus/efeitos dos fármacos , Imidazóis/toxicidade , Compostos de Piridínio/toxicidade , Tensoativos/toxicidade , Triticum/efeitos dos fármacos , Cátions , Membrana Celular/química , Membrana Celular/efeitos dos fármacos , Cucumis sativus/crescimento & desenvolvimento , Germinação/efeitos dos fármacos , Imidazóis/química , Bicamadas Lipídicas/química , Simulação de Dinâmica Molecular , Compostos de Piridínio/química , Compostos de Piridínio/farmacologia , Plântula/efeitos dos fármacos , Plântula/crescimento & desenvolvimento , Sementes/efeitos dos fármacos , Sementes/crescimento & desenvolvimento , Relação Estrutura-Atividade , Tensoativos/química , Triticum/crescimento & desenvolvimento
14.
Nat Commun ; 11(1): 4572, 2020 09 11.
Artigo em Inglês | MEDLINE | ID: mdl-32917907

RESUMO

Undomesticated wild species, crop wild relatives, and landraces represent sources of variation for wheat improvement to address challenges from climate change and the growing human population. Here, we study 56,342 domesticated hexaploid, 18,946 domesticated tetraploid and 3,903 crop wild relatives in a massive-scale genotyping and diversity analysis. Using DArTseqTM technology, we identify more than 300,000 high-quality SNPs and SilicoDArT markers and align them to three reference maps: the IWGSC RefSeq v1.0 genome assembly, the durum wheat genome assembly (cv. Svevo), and the DArT genetic map. On average, 72% of the markers are uniquely placed on these maps and 50% are linked to genes. The analysis reveals landraces with unexplored diversity and genetic footprints defined by regions under selection. This provides fertile ground to develop wheat varieties of the future by exploring specific gene or chromosome regions and identifying germplasm conserving allelic diversity missing in current breeding programs.


Assuntos
Variação Genética , Genoma de Planta , Triticum/genética , Alelos , Domesticação , Genótipo , Modelos Genéticos , Polimorfismo de Nucleotídeo Único , Alinhamento de Sequência , Tetraploidia
15.
Ecotoxicol Environ Saf ; 202: 110959, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32800231

RESUMO

Long-term field experiments were performed to evaluate the phytotoxic properties of fungal metabolites in oil-contaminated soil and to assess the impact of contamination on the allelopathic activity of soil mycobiota. Two contrasting soils of Northwest Russia (sandy and loamy podzols) exposed to oil contamination underwent changes in abundance and allelopathic activities of soil fungi. Shifts within the microbial community caused by oil contamination affected not only oil-decomposition rates but also ecotoxicity of contaminated soil. There were significant differences in soil toxicity dynamics between sandy and loamy podzols. Four years after contamination, ecotoxicity of loamy podzol decreased, whereas sandy podzol remained highly toxic even nine years after contamination. The abundance and allelopathic activity of fungi is correlated with hydrocarbon degradation dynamics. The soil fungal community demonstrated high allelopathic activity which decreased over time in fertile loamy podzolic soil, whereas in poor sandy podzolic soil it remained high over the nine-year monitoring period. The results illustrate how oil contamination may influence allelopathic interactions in soil and demonstrate the advantage of using fungal metabolite toxicity test for testing of oil-contaminated soil samples.


Assuntos
Fungos/efeitos dos fármacos , Hidrocarbonetos/toxicidade , Micotoxinas/toxicidade , Petróleo/toxicidade , Microbiologia do Solo , Poluentes do Solo/análise , Animais , Biodegradação Ambiental , Daphnia/efeitos dos fármacos , Daphnia/crescimento & desenvolvimento , Ecotoxicologia , Fungos/metabolismo , Hidrocarbonetos/análise , Micotoxinas/metabolismo , Petróleo/análise , Federação Russa , Solo/química , Testes de Toxicidade , Triticum/efeitos dos fármacos , Triticum/crescimento & desenvolvimento
16.
Sheng Wu Gong Cheng Xue Bao ; 36(7): 1356-1364, 2020 Jul 25.
Artigo em Chinês | MEDLINE | ID: mdl-32748593

RESUMO

Salinity is the most important factor for the growth of crops. It is an effective method to alleviate the toxic effect caused by salt stress using saline-alkali-tolerant and growth-promoting bacteria in agriculture. Seven salt-tolerant bacteria were screened from saline-alkali soil, and the abilities of EPS production, alkalinity reduction and IAA production of the selected strains were investigated. A dominant strain DB01 was evaluated. The abilities of EPS production, alkalinity reduction and IAA production of strain DB01 were 0.21 g/g, 8.7% and 8.97 mg/L, respectively. The isolate was identified as Halomonas aquamarina by partial sequencing analysis of its 16S rRNA genes, and had the ability to inhibit the growth of Fusarium oxysporum f. sp., Alternaria solani, Phytophthora sojae and Rhizoctonia cerealis. It also could promote root length and germination rate of wheat seedlings under salt stress. Halomonas aquamarina can provide theoretical basis for the development of soil microbial resources and the application in saline-alkali soil improvement.


Assuntos
Álcalis , Raízes de Plantas , Tolerância ao Sal , Microbiologia do Solo , Álcalis/metabolismo , Bactérias/efeitos dos fármacos , Bactérias/genética , Halomonas/genética , Raízes de Plantas/microbiologia , RNA Ribossômico 16S/genética , Tolerância ao Sal/genética , Plântula/crescimento & desenvolvimento , Plântula/microbiologia , Solo/química , Triticum/microbiologia
17.
Plant Mol Biol ; 104(1-2): 173-185, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32734417

RESUMO

KEY MESSAGE: A novel and major QTL for the effective tiller number was identified on chromosomal arm 1BL and validated in two genetic backgrounds The effective tiller number (ETN) substantially influences plant architecture and the wheat yield improvement. In this study, we constructed a genetic map of the 2SY (20828/SY95-71) recombinant inbred line population based on the Wheat 55K array as well as the simple sequence repeat (SSR) and Kompetitive Allele Specific PCR (KASP) markers. A comparison between the genetic and physical maps indicated the marker positions were consistent in the two maps. Additionally, we identified seven tillering-related quantitative trait locus (QTLs), including Qetn-sau-1B.1, which is a major QTL localized to a 6.17-cM interval flanked by markers AX-89635557 and AX-111544678 on chromosome 1BL. The Qetn-sau-1B.1 QTL was detected in eight environments and explained 12.12-55.71% of the phenotypic variance. Three genes associated with the ETN were detected in the physical interval of Qetn-sau-1B.1. We used a tightly linked KASP marker, KASP-AX-110129912, to further validate this QTL in two other populations with different genetic backgrounds. The results indicated that Qetn-sau-1B.1 significantly increased the ETN by up to 23.5%. The results of this study will be useful for the precise mapping and cloning of Qetn-sau-1B.1.


Assuntos
Cromossomos de Plantas , Locos de Características Quantitativas/genética , Triticum/genética , Bangladesh , Mapeamento Cromossômico , Marcadores Genéticos/genética , Genótipo , Repetições de Microssatélites , Anotação de Sequência Molecular , Fenótipo
18.
PLoS One ; 15(8): e0233665, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32804955

RESUMO

Oligomycins are macrolide antibiotics, produced by Streptomyces spp. that show antagonistic effects against several microorganisms such as bacteria, fungi, nematodes and the oomycete Plasmopara viticola. Conidiogenesis, germination of conidia and formation of appressoria are determining factors pertaining to pathogenicity and successful diseases cycles of filamentous fungal phytopathogens. The goal of this research was to evaluate the in vitro suppressive effects of two oligomycins, oligomycin B and F along with a commercial fungicide Nativo® 75WG on hyphal growth, conidiogenesis, conidial germination, and appressorial formation of the wheat blast fungus, Magnaporthe oryzae Triticum (MoT) pathotype. We also determined the efficacy of these two oligomycins and the fungicide product in vivo in suppressing wheat blast with a detached leaf assay. Both oligomycins suppressed the growth of MoT mycelium in a dose dependent manner. Between the two natural products, oligomycin F provided higher inhibition of MoT hyphal growth compared to oligomycin B with a minimum inhibitory concentration of 0.005 and 0.05 µg/disk, respectively. The application of the compounds completely halted conidial formation of the MoT mycelium in agar medium. Further bioassays showed that these compounds significantly inhibited MoT conidia germination and induced lysis. The compounds also caused abnormal germ tube formation and suppressed appressorial formation of germinated spores. Interestingly, the application of these macrolides significantly inhibited wheat blast on detached leaves of wheat. This is the first report on the inhibition of mycelial growth, conidiogenesis, germination of conidia, deleterious morphological changes in germinated conidia, and suppression of blast disease of wheat by oligomycins from Streptomyces spp. Further study is needed to unravel the precise mode of action of these natural compounds and consider them as biopesticides for controlling wheat blast.


Assuntos
Magnaporthe/efeitos dos fármacos , Magnaporthe/patogenicidade , Oligomicinas/farmacologia , Doenças das Plantas/microbiologia , Doenças das Plantas/prevenção & controle , Triticum/microbiologia , Agentes de Controle Biológico/farmacologia , Grão Comestível/microbiologia , Microbiologia de Alimentos , Fungicidas Industriais/farmacologia , Hifas/efeitos dos fármacos , Hifas/crescimento & desenvolvimento , Magnaporthe/crescimento & desenvolvimento , Micélio/efeitos dos fármacos , Micélio/crescimento & desenvolvimento , Esporos Fúngicos/efeitos dos fármacos , Esporos Fúngicos/crescimento & desenvolvimento
19.
PLoS One ; 15(8): e0236326, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32822363

RESUMO

This study aimed to test whether or not where people come from and move to impacts their method for dealing with stress. We investigated this research question among newcomers crossing between the rice and wheat farming regions in China-south and north China, respectively. New evidence suggests wheat-farming agriculture fosters a coping strategy of changing the environment (primary coping), while rice-farming regions foster the converse strategy of fitting into the environment (secondary coping). Using two longitudinal studies on newcomers at universities located in both the rice and wheat farming regions, we hypothesized that students from south China (rice region) at a university in north China (wheat region) would use more primary coping and it would lead to better adaptation (Study 1). In contrast, students from wheat-farming regions moving to a rice university would benefit from secondary coping as an effective strategy for buffering stress (Study 2). Results indicated that for students from rice-farming regions who were studying universities in wheat-farming regions, secondary coping was damaging and attenuated the stress-adaptation relationship. However, in study 2, the reverse was found, as secondary coping was found to buffer the negative effects of stress on sociocultural adaptation for students from wheat-farming regions who were studying at universities in rice-farming regions. This study lends further support to the theory that ecological factors impact how individuals cope with the acculturative stress of moving to a new environment.


Assuntos
Aculturação , Adaptação Psicológica , Produção Agrícola , Comparação Transcultural , Migração Humana , Adolescente , China , Produtos Agrícolas , Fazendas , Feminino , Geografia , Humanos , Estudos Longitudinais , Masculino , Oryza , Estudantes/psicologia , Triticum , Universidades , Adulto Jovem
20.
Bioresour Technol ; 316: 123882, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32739576

RESUMO

Lignocellulosic biomass fractionaion into its three major components is critically important for efficient feedstock utilization. The hydrothermal-ethanol method has broad application as its first step, hydrothermal treatment, provides high hemicellulose separation efficiency. However, it severely inhibits the delignification on the subsequent ethanol extraction. In this study, the second step, ethanol extraction, was facilitated by the addition of 3% NaOH and 3% H2O2, resulting in a significant improvement of lignin separation (by 48.2%). SEM, AFM, XPS, and XRD were used to characterize the surface composition of the remaining solids (crude cellulose) while the structure of isolated lignin was characterized by FT-IR, CP/MAS 13C NMR, GPC and TGA. The lignin samples isolated with both facilitated and non-facilitated ethanol extraction were compared to elucidate the lignin removal mechanism. The results showed that lignin degradation and crosslinking/polymerization occur in parallel during both the hydrothermal treatment and ethanol extraction.


Assuntos
Etanol , Triticum , Peróxido de Hidrogênio , Hidrólise , Lignina , Espectroscopia de Infravermelho com Transformada de Fourier
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA