Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 5.769
Filtrar
1.
PLoS One ; 15(8): e0238042, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32841280

RESUMO

Long-term chemical fertilizer input causes soil organic matter losses, structural compaction, and changes in soil water and nutrient availability, which have been subdued in the most of dry farmland in China. The concept of "more efficiency with less fertilizer input" has been proposed and is urgently needed in current agriculture. Application of chemical fertilizer combined with organic manure (OM) could be a solution for soil protection and sustainable production of dry-land maize (Zea mays. L). Field research over three consecutive years on the Loess Plateau of China was conducted to evaluate the integrated effects of chemical fertilizer strategies and additional OM input on soil nutrients availability and water use in maize. The results showed that, after harvest, soil bulk density decreased significantly with OM application, concomitant with 11.9, 18.7 and 97.8% increases in topsoil total nitrogen, organic matter, and available phosphorus contents, respectively, compared with those under equal chemical NPK input. Water use in the 1.0-1.5 m soil profile was improved, therefore, the soil conditions were better for maize root growth, leaf area and shoot biomass of individual maize plants increased significantly with OM application. Optimized NPK strategies increased grain yield and water use efficiency by 18.5 and 20.6%, respectively, compared to only chemical NP input. Furthermore, additional OM input promoted yield and water use efficiency by 8.9 and 5.8%, respectively. Addition of OM promotes sustainable soil and maize grain productivity as well as friendly soil environmental management of dry land farming.


Assuntos
Esterco/análise , Nutrientes/metabolismo , Compostos Orgânicos/farmacologia , Solo/química , Água/análise , Zea mays/efeitos dos fármacos , Zea mays/crescimento & desenvolvimento , Biomassa , China , Fertilizantes/análise , Nitrogênio/metabolismo , Fósforo/metabolismo , Desenvolvimento Sustentável , Zea mays/metabolismo
2.
BMC Bioinformatics ; 21(1): 365, 2020 Aug 24.
Artigo em Inglês | MEDLINE | ID: mdl-32838742

RESUMO

BACKGROUND: The amount of published full-text articles has increased dramatically. Text mining tools configure an essential approach to building biological networks, updating databases and providing annotation for new pathways. PESCADOR is an online web server based on LAITOR and NLProt text mining tools, which retrieves protein-protein co-occurrences in a tabular-based format, adding a network schema. Here we present an HPC-oriented version of PESCADOR's native text mining tool, renamed to LAITOR4HPC, aiming to access an unlimited abstract amount in a short time to enrich available networks, build new ones and possibly highlight whether fields of research have been exhaustively studied. RESULTS: By taking advantage of parallel computing HPC infrastructure, the full collection of MEDLINE abstracts available until June 2017 was analyzed in a shorter period (6 days) when compared to the original online implementation (with an estimated 2 years to run the same data). Additionally, three case studies were presented to illustrate LAITOR4HPC usage possibilities. The first case study targeted soybean and was used to retrieve an overview of published co-occurrences in a single organism, retrieving 15,788 proteins in 7894 co-occurrences. In the second case study, a target gene family was searched in many organisms, by analyzing 15 species under biotic stress. Most co-occurrences regarded Arabidopsis thaliana and Zea mays. The third case study concerned the construction and enrichment of an available pathway. Choosing A. thaliana for further analysis, the defensin pathway was enriched, showing additional signaling and regulation molecules, and how they respond to each other in the modulation of this complex plant defense response. CONCLUSIONS: LAITOR4HPC can be used for an efficient text mining based construction of biological networks derived from big data sources, such as MEDLINE abstracts. Time consumption and data input limitations will depend on the available resources at the HPC facility. LAITOR4HPC enables enough flexibility for different approaches and data amounts targeted to an organism, a subject, or a specific pathway. Additionally, it can deliver comprehensive results where interactions are classified into four types, according to their reliability.


Assuntos
Software , Arabidopsis/metabolismo , Proteínas de Arabidopsis/metabolismo , Bases de Dados Factuais , Proteínas de Plantas/metabolismo , Mapas de Interação de Proteínas , Zea mays/metabolismo
3.
PLoS One ; 15(7): e0234610, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32645008

RESUMO

The objective of this study was to evaluate the effect of the physical form of starter and inclusion of hay in the diet of preweaning dairy calves on performance, digestibility, ruminal development, and mRNA expression of genes involved in ruminal metabolism. Holstein × Gyr crossbred male calves (n = 38 1day old) were assigned to 3 treatments for 9 weeks: Control (n = 13; pellet starter with 4 mm diameter and 18 mm length and 4% steam-flaked corn), Ground (n = 12; same starter of the control but ground pass through a 4.0 mm sieve), or Ground plus 5% chopped Tifton hay GH (n = 13). All calves were fed 4 L/d of whole milk up to 63 d of age and were abruptly weaned at 64 d of age. Water and diets were offered ad libitum. Samples of ruminal contents were obtained from all animals at 30, 45, and 60 d of age to evaluate pH, ammonia nitrogen, and volatile fatty acids (VFA). At 55 d of age, an apparent digestibility assay was performed using 18 animals (n = 6/ treatment). At 65 d of age, the 18 animals were euthanized to evaluate the development of the digestive tract. The physical form of starter and the dietary inclusion of hay did not influence starter intake (Control 326 g/d, Ground 314 g/d and GH 365 g/d), daily weight gain (Control 541g/d, Ground 531g/d and GH 606g/d), feed efficiency, apparent nutrient digestibility, energy partitioning, nitrogen balance, ruminal pH, ammonia nitrogen concentration, VFA, the development of the digestive tract and the mRNA expression of genes involved in AGV metabolism.


Assuntos
Ração Animal/análise , Criação de Animais Domésticos/métodos , Dieta/veterinária , Animais , Animais Recém-Nascidos/crescimento & desenvolvimento , Peso Corporal , Bovinos , Fibras na Dieta/metabolismo , Masculino , Leite/metabolismo , Nutrientes , Rúmen/metabolismo , Desmame , Ganho de Peso , Zea mays/metabolismo
4.
PLoS One ; 15(7): e0232811, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32614852

RESUMO

In the present work, the olive mill solid waste (OMSW)-derived biochar (BC) was produced at various pyrolytic temperatures (300-700°C) and characterized to investigate its potential negative versus positive application effects on pH, electrical conductivity (EC), and nutrients (P, K, Na, Ca, Mg, Fe, Mn, Zn, and Cu) availability in a calcareous loamy sand soil. Therefore, a greenhouse pot experiment with maize (Zea mays L.) was conducted using treatments consisting of a control (CK), inorganic fertilizer of NPK (INF), and 1% and 3% (w/w) of OMSW-derived BCs. The results showed that BC yield, volatile matter, functional groups, and zeta potential decreased with pyrolytic temperature, whereas BC pH, EC, and its contents of ash and fixed carbon increased with pyrolytic temperature. The changes in the BC properties with increasing pyrolytic temperatures reflected on soil pH, EC and the performance of soil nutrients availability. The BC application, especially with increasing pyrolytic temperature and/or application rate, significantly increased soil pH, EC, NH4OAc-extractable K, Na, Ca, and Mg, and ammonium bicarbonate-diethylenetriaminepentaacetic acid (AB-DTPA)-extractable Fe and Zn, while AB-DTPA-extractable Mn decreased. The application of 1% and 3% BC, respectively, increased the NH4OAc-extractable K by 2.5 and 5.2-fold for BC300, by 3.2 and 8.0-fold for BC500, and by 3.3 and 8.9-fold for BC700 compared with that of untreated soil. The results also showed significant increase in shoot content of K, Na, and Zn, while there was significant decrease in shoot content of P, Ca, Mg, and Mn. Furthermore, no significant effects were observed for maize growth as a result of BC addition. In conclusion, OMSW-derived BC can potentially have positive effects on the enhancement of soil K availability and its plant content but it reduced shoot nutrients, especially for P, Ca, Mg, and Mn; therefore, application of OMSW-derived BC to calcareous soil might be restricted.


Assuntos
Carvão Vegetal/farmacologia , Nutrientes/análise , Olea/química , Areia/química , Solo/química , Carvão Vegetal/química , Concentração de Íons de Hidrogênio , Minerais/metabolismo , Nutrientes/metabolismo , Fatores de Tempo , Zea mays/efeitos dos fármacos , Zea mays/crescimento & desenvolvimento , Zea mays/metabolismo
5.
PLoS One ; 15(7): e0236571, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32730284

RESUMO

The occurrence of genotype by environment interaction (G x E), which is defined as the differential response of genotypes to environmental variation, is frequently reported in maize cultures, making it challenging to recommend cultivars. Methods allowing to study the potential nonlinear pattern of genotype responses to environmental variation allied to prior beliefs on unknown parameters are interesting to evaluate the phenotypic adaptability and stability of genotypes. In this context, the present study aimed to assess the adaptability and stability of maize hybrids, by using the Bayesian segmented regression model, and evaluate the efficacy of using informative and minimally informative prior distributions for the selection of cultivars. Randomized complete-block design experiments were carried out to study the yield (kg/ha) of 25 maize hybrids, in 22 different environments, in Northeastern Brazil. The Bayesian segmented regression model fitted using informative prior distributions presented lower credibility intervals and Deviance Criterium of Information values, compared to those obtained by fitting using minimally informative distributions. Therefore, the model using informative prior distributions was considered for the adaptability and stability evaluation of maize genotypes. Once most northeastern farmers in Brazil have limited capital, the genotype P4285HX should be considered for planting, due to its high yield performance and adaptability to unfavorable environments.


Assuntos
Modelos Genéticos , Zea mays/genética , Adaptação Fisiológica/genética , Teorema de Bayes , Interação Gene-Ambiente , Genótipo , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/metabolismo , Zea mays/crescimento & desenvolvimento , Zea mays/metabolismo
6.
PLoS One ; 15(7): e0236634, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32706842

RESUMO

Potassium (K) input is essential for the improvement of soil fertility in agricultural systems. However, organic amendment may differ from mineral K fertilization with respect to modifying the soil K transformation among different fractions, affecting soil K availability. We conducted a 60-day lab incubation experiment to evaluate the response of soil K dynamics and availability in various fractions with a view to simulating crop residue return and chemical K fertilization in an Anthrosol of northwest China. The tested soil was divided into two main groups, no K fertilization (K0) and K fertilization (K1), each of which was subjected to four straw addition regimes: no straw addition (Control), wheat straw addition (WS), maize straw addition (MS), and both wheat straw and maize straw addition (WS+MS). Soil K levels in the available (AK) and non-exchangeable (NEK) fractions were both significantly increased after K addition, following the order of K>WS>MS. Fertilizer K was the most efficient K source, demonstrating a 72.9% efficiency in increasing soil AK, while wheat and maize straw exhibited efficiencies of 47.1% and 39.3%, respectively. Furthermore, K fertilization and wheat and maize straw addition increased the soil AK in a cumulative manner when used in combination. The mobility factor (MF) and reduced partition index (IR) of soil K were used to quantitate the comprehensive soil K mobility and stability, respectively. Positive relationships were observed between the MF and all relatively available fractions of soil K, whereas the IR value of soil K correlated negatively with both MF and all available fractions of soil K. In conclusion, straw amendment could be inferior to mineral K fertilization in improving soil K availability when they were almost equal in the net K input. Crop straw return coupled with K fertilization can be a promising strategy for improving both soil K availability and cycling in soil-plant systems.


Assuntos
Agricultura , Potássio/química , Solo/química , Triticum/metabolismo , Zea mays/metabolismo , China , Fertilizantes/análise , Potássio/metabolismo , Análise de Componente Principal , Triticum/química , Zea mays/química
7.
Proc Natl Acad Sci U S A ; 117(28): 16649-16659, 2020 07 14.
Artigo em Inglês | MEDLINE | ID: mdl-32586957

RESUMO

Low availability of nitrogen (N) is often a major limiting factor to crop yield in most nutrient-poor soils. Arbuscular mycorrhizal (AM) fungi are beneficial symbionts of most land plants that enhance plant nutrient uptake, particularly of phosphate. A growing number of reports point to the substantially increased N accumulation in many mycorrhizal plants; however, the contribution of AM symbiosis to plant N nutrition and the mechanisms underlying the AM-mediated N acquisition are still in the early stages of being understood. Here, we report that inoculation with AM fungus Rhizophagus irregularis remarkably promoted rice (Oryza sativa) growth and N acquisition, and about 42% of the overall N acquired by rice roots could be delivered via the symbiotic route under N-NO3 - supply condition. Mycorrhizal colonization strongly induced expression of the putative nitrate transporter gene OsNPF4.5 in rice roots, and its orthologs ZmNPF4.5 in Zea mays and SbNPF4.5 in Sorghum bicolor OsNPF4.5 is exclusively expressed in the cells containing arbuscules and displayed a low-affinity NO3 - transport activity when expressed in Xenopus laevis oocytes. Moreover, knockout of OsNPF4.5 resulted in a 45% decrease in symbiotic N uptake and a significant reduction in arbuscule incidence when NO3 - was supplied as an N source. Based on our results, we propose that the NPF4.5 plays a key role in mycorrhizal NO3 - acquisition, a symbiotic N uptake route that might be highly conserved in gramineous species.


Assuntos
Proteínas de Transporte de Ânions/metabolismo , Glomeromycota/fisiologia , Micorrizas/fisiologia , Nitrogênio/metabolismo , Oryza/metabolismo , Proteínas de Plantas/metabolismo , Proteínas de Transporte de Ânions/genética , Regulação da Expressão Gênica de Plantas , Nitratos/metabolismo , Oryza/genética , Oryza/crescimento & desenvolvimento , Oryza/microbiologia , Proteínas de Plantas/genética , Raízes de Plantas/genética , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/metabolismo , Raízes de Plantas/microbiologia , Sorghum/genética , Sorghum/metabolismo , Sorghum/microbiologia , Zea mays/genética , Zea mays/metabolismo , Zea mays/microbiologia
8.
Proc Natl Acad Sci U S A ; 117(24): 13800-13809, 2020 06 16.
Artigo em Inglês | MEDLINE | ID: mdl-32493747

RESUMO

While colocalization within a bacterial operon enables coexpression of the constituent genes, the mechanistic logic of clustering of nonhomologous monocistronic genes in eukaryotes is not immediately obvious. Biosynthetic gene clusters that encode pathways for specialized metabolites are an exception to the classical eukaryote rule of random gene location and provide paradigmatic exemplars with which to understand eukaryotic cluster dynamics and regulation. Here, using 3C, Hi-C, and Capture Hi-C (CHi-C) organ-specific chromosome conformation capture techniques along with high-resolution microscopy, we investigate how chromosome topology relates to transcriptional activity of clustered biosynthetic pathway genes in Arabidopsis thaliana Our analyses reveal that biosynthetic gene clusters are embedded in local hot spots of 3D contacts that segregate cluster regions from the surrounding chromosome environment. The spatial conformation of these cluster-associated domains differs between transcriptionally active and silenced clusters. We further show that silenced clusters associate with heterochromatic chromosomal domains toward the periphery of the nucleus, while transcriptionally active clusters relocate away from the nuclear periphery. Examination of chromosome structure at unrelated clusters in maize, rice, and tomato indicates that integration of clustered pathway genes into distinct topological domains is a common feature in plant genomes. Our results shed light on the potential mechanisms that constrain coexpression within clusters of nonhomologous eukaryotic genes and suggest that gene clustering in the one-dimensional chromosome is accompanied by compartmentalization of the 3D chromosome.


Assuntos
Arabidopsis/genética , Cromossomos de Plantas/genética , Lycopersicon esculentum/genética , Família Multigênica , Proteínas de Plantas/genética , Zea mays/genética , Arabidopsis/metabolismo , Cromossomos de Plantas/metabolismo , Genoma de Planta , Lycopersicon esculentum/metabolismo , Oryza/genética , Oryza/metabolismo , Proteínas de Plantas/metabolismo , Zea mays/metabolismo
9.
PLoS One ; 15(4): e0232294, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32353025

RESUMO

Spring maize sowing occurs during a period of low temperature (LT) in Northeast China, and the LT suppresses nitrogen (N) metabolism and photosynthesis, further reducing dry matter accumulation. Diethyl aminoethyl hexanoate (DA-6) improves N metabolism; hence, we studied the effects of DA-6 on maize seedlings under LT conditions. The shoot and root fresh weight and dry weight decreased by 17.70%~20.82% in the LT treatment, and decreased by 5.81%~13.57% in the LT + DA-6 treatment on the 7th day, respectively. Exogenous DA-6 suppressed the increases in ammonium (NH4+) content and glutamate dehydrogenase (GDH) activity, and suppressed the decreases in nitrate (NO3-) and nitrite (NO2-) contents, and activities of nitrate reductase (NR), nitrite reductase (NiR), glutamine synthetase (GS), glutamate synthase (GOGAT) and transaminase activities. NiR activity was most affected by DA-6 under LT conditions. Additionally, exogenous DA-6 suppressed the net photosynthetic rate (Pn) decrease, and the suppressed the increases of superoxide anion radical (O2·-) generation rate and hydrogen peroxide (H2O2) content. Taken together, our results suggest that exogenous DA-6 mitigated the repressive effects of LT on N metabolism by improving photosynthesis and modulating oxygen metabolism, and subsequently enhanced the LT tolerance of maize seedlings.


Assuntos
Caproatos/farmacologia , Nitrogênio/metabolismo , Plântula/efeitos dos fármacos , Plântula/metabolismo , Zea mays/efeitos dos fármacos , Zea mays/metabolismo , Compostos de Amônio/metabolismo , China , Temperatura Baixa , Glutamato Sintase/metabolismo , Glutamato-Amônia Ligase/metabolismo , Peróxido de Hidrogênio/metabolismo , Nitrato Redutase/metabolismo , Nitratos/metabolismo , Nitrito Redutases/metabolismo , Nitritos/metabolismo , Fotossíntese/efeitos dos fármacos , Proteínas de Plantas/metabolismo , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/metabolismo , Brotos de Planta/efeitos dos fármacos , Brotos de Planta/metabolismo
10.
PLoS One ; 15(5): e0232269, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32357181

RESUMO

Susceptibility of plants to abiotic stresses, including extreme temperatures, salinity and drought, poses an increasing threat to crop productivity worldwide. Here the drought-induced response of maize was modulated by applications of methyl jasmonate (MeJA) and salicylic acid (SA) to seeds prior to sowing and to leaves prior to stress treatment. Pot experiments were conducted to ascertain the effects of exogenous applications of these hormones on maize growth, physiology and biochemistry under drought stress and well-watered (control) conditions. Maize plants were subjected to single as well as combined pre-treatments of MeJA and SA. Drought stress severely affected maize morphology and reduced relative water content, above and below-ground biomass, rates of photosynthesis, and protein content. The prolonged water deficit also led to increased relative membrane permeability and oxidative stress induced by the production of malondialdehyde (from lipid peroxidation), lipoxygenase activity (LOX) and the production of H2O2. The single applications of MeJA and SA were not found to be effective in maize for drought tolerance while the combined pre-treatments with exogenous MeJA+SA mitigated the adverse effects of drought-induced oxidative stress, as reflected in lower levels of lipid peroxidation, LOX activity and H2O2. The same pre-treatment also maintained adequate water status of the plants under drought stress by increasing osmolytes including proline, total carbohydrate content and total soluble sugars. Furthermore, exogenous applications of MeJA+SA approximately doubled the activities of the antioxidant enzymes catalase, peroxidase and superoxide dismutase. Pre-treatment with MeJA alone gave the highest increase in drought-induced production of endogenous abscisic acid (ABA). Pre-treatment with MeJA+SA partially prevented drought-induced oxidative stress by modulating levels of osmolytes and endogenous ABA, as well as the activities of antioxidant enzymes. Taken together, the results show that seed and foliar pre-treatments with exogenous MeJA and/or SA can have positive effects on the responses of maize seedlings to drought.


Assuntos
Acetatos/farmacologia , Ciclopentanos/farmacologia , Secas , Oxilipinas/farmacologia , Reguladores de Crescimento de Planta/farmacologia , Ácido Salicílico/farmacologia , Estresse Fisiológico/efeitos dos fármacos , Zea mays/efeitos dos fármacos , Antioxidantes/metabolismo , Carotenoides/metabolismo , Clorofila/metabolismo , Concentração Osmolar , Estresse Oxidativo/efeitos dos fármacos , Proteínas de Plantas/metabolismo , Análise de Componente Principal , Sementes/efeitos dos fármacos , Solo , Zea mays/crescimento & desenvolvimento , Zea mays/metabolismo
11.
PLoS One ; 15(5): e0233674, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32469984

RESUMO

Timing and rate of nitrogen (N) fertilizer application can influence maize (Zea mays L.) grain yield, N uptake, and nitrogen use efficiency (NUE) parameters, but results have been inconsistent across the upper Midwest. This study compared single (fall and preplant) and split applications of differing N rates for maize under irrigated conditions on loamy sand at Becker, MN and under rainfed conditions on loam and clay loam soils at Lamberton, MN and Waseca, MN, respectively, in 2014 to 2016. Fall and preplant applications of N were applied at recommended and 125% of recommended rates (RN) according to University of Minnesota guidelines. Split-application treatments included a two-way (Sp, applied at 75% and 100% of RN) and a three-way split (TSp applied at 50%, 75%, and 100% of RN), with the total N rate equally split among application times. At Becker, maize grain yield with TSp was 12.6 to 15.7 Mg ha-1 among years and significantly greater than that with fall or preplant treatments. The TSp treatment also improved agronomic efficiency (AE) and recovery efficiency (RE) by an average of 30% over fall or preplant treatments. At Lamberton, maize grain yield, AE and RE did not differ among treatments. However, TSp75 improved AE by 8.3 kg kg-1 while producing comparable yields to fall and preplant treatments. At Waseca, Sp or TSp improved grain yield and AE compared with fall treatments. These results suggest that split applications of N can increase maize grain yield, AE, and RE on irrigated coarse-textured soils and applying N fertilizer near planting or as a split application can improve N management on non-irrigated clay loam soils.


Assuntos
Produção Agrícola/métodos , Fertilizantes , Nitrogênio , Zea mays/crescimento & desenvolvimento , Irrigação Agrícola , Fertilizantes/análise , Nitrogênio/análise , Nitrogênio/metabolismo , Chuva , Solo/química , Zea mays/metabolismo
12.
Mol Genet Genomics ; 295(5): 1091-1102, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32409904

RESUMO

Long non-coding RNAs (lncRNAs) play a broad spectrum of distinctive regulatory roles through interactions with proteins. However, only a few plant lncRNAs have been experimentally characterized. We propose GPLPI, a graph representation learning method, to predict plant lncRNA-protein interaction (LPI) from sequence and structural information. GPLPI employs a generative model using long short-term memory (LSTM) with graph attention. Evolutionary features are extracted using frequency chaos game representation (FCGR). Manifold regularization and l2-norm are adopted to obtain discriminant feature representations and mitigate overfitting. The model captures locality preserving and reconstruction constraints that lead to better generalization ability. Finally, potential interactions between lncRNAs and proteins are predicted by integrating catboost and regularized Logistic regression based on L-BFGS optimization algorithm. The method is trained and tested on Arabidopsis thaliana and Zea mays datasets. GPLPI achieves accuracies of 85.76% and 91.97% respectively. The results show that our method consistently outperforms other state-of-the-art methods.


Assuntos
Biologia Computacional/métodos , Proteínas de Plantas/metabolismo , Plantas/metabolismo , RNA Longo não Codificante/metabolismo , Algoritmos , Arabidopsis/metabolismo , Aprendizado Profundo , Modelos Logísticos , Modelos Moleculares , Proteínas de Plantas/química , RNA Longo não Codificante/química , RNA de Plantas/química , RNA de Plantas/metabolismo , Zea mays/metabolismo
13.
Food Chem ; 327: 127058, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-32464462

RESUMO

A "turn-on" fluorescence sensor was developed for total detection of fumonisin B1, B2 and B3 (FB1, FB2 and FB3) in maize samples. Rhodamine B isothiocyanate (RBITC) and gold nanoparticles (AuNPs) were employed as the energy donor-acceptor pairs. The intensity of restored fluorescence was inversely proportional to the concentration of the FBs. The limit of detection (LOD) of the sensor for FB1 was 23.80 pg/mL. The coefficient of variation (CV) was both less than 7% for intra- and inter-assay. The linear range was from 51.39 to 2125.92 pg/mL. The average recoveries of FBs from maize samples were ranged from 88.7% to 107.2%. The correlation coefficient of the results between the developed sensor and LC-MS/MS was 0.9970. To fulfill the procedure of the assay, only 46 min was needed. These results suggest that the fluorescence "turn-on" sensor has great potential applications in the analysis of FBs in maize samples.


Assuntos
Cisteamina/química , Fumonisinas/análise , Espectrometria de Fluorescência/métodos , Contaminação de Alimentos/análise , Ouro/química , Limite de Detecção , Nanopartículas Metálicas/química , Rodaminas/química , Zea mays/química , Zea mays/metabolismo
14.
Proc Natl Acad Sci U S A ; 117(22): 12464-12471, 2020 06 02.
Artigo em Inglês | MEDLINE | ID: mdl-32424100

RESUMO

Plant cuticles are composed of wax and cutin and evolved in the land plants as a hydrophobic boundary that reduces water loss from the plant epidermis. The expanding maize adult leaf displays a dynamic, proximodistal gradient of cuticle development, from the leaf base to the tip. Laser microdissection RNA Sequencing (LM-RNAseq) was performed along this proximodistal gradient, and complementary network analyses identified potential regulators of cuticle biosynthesis and deposition. A weighted gene coexpression network (WGCN) analysis suggested a previously undescribed function for PHYTOCHROME-mediated light signaling during the regulation of cuticular wax deposition. Genetic analyses reveal that phyB1 phyB2 double mutants of maize exhibit abnormal cuticle composition, supporting the predictions of our coexpression analysis. Reverse genetic analyses also show that phy mutants of the moss Physcomitrella patens exhibit abnormal cuticle composition, suggesting an ancestral role for PHYTOCHROME-mediated, light-stimulated regulation of cuticle development during plant evolution.


Assuntos
Folhas de Planta/crescimento & desenvolvimento , Transcriptoma , Zea mays/genética , Bryopsida/genética , Bryopsida/metabolismo , Bryopsida/efeitos da radiação , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas/efeitos da radiação , Luz , Folhas de Planta/genética , Folhas de Planta/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Transcriptoma/efeitos da radiação , Zea mays/crescimento & desenvolvimento , Zea mays/metabolismo , Zea mays/efeitos da radiação
15.
Sheng Wu Gong Cheng Xue Bao ; 36(3): 518-528, 2020 Mar 25.
Artigo em Chinês | MEDLINE | ID: mdl-32237545

RESUMO

In order to explore the effect of intercropping on the uptake of heavy metal cadmium (Cd), pot experiments were undertaken using three different planting methods: monoculture, restrictive intercropping and intercropping. The effects of Cd accumulation in different plant parts, and their causes, were examined using a plant species regarded as a relatively high heavy metal accumulator (tomato: Lycopersicon esculentum var. Zhongshu 4) and a species regarded as a relatively low heavy metal accumulator (maize: Zea mays L. var. Jinzhumi). Cd levels for all experiments were 3.70 mg/kg. Results indicate that restricted intercropping and intercropping of tomato and maize increased the accumulation of Cd (from 13.52 mg/kg to 24.94 mg/kg and 27.30 mg/kg in tomato leaf, respectively). Compared with the control group, pH levels in soil surrounding tomato roots in the intercropped samples decreased and the activity of acid phosphatase increased, while the activity of urease decreased. Intercropping can also change the structure of the crop root microorganism population, increase the abundance of microbiological species that promote the uptake of heavy metals, and finally achieve high accumulation of Cd in tomatoes. Our research results provide reference for controlling soil heavy metal pollution and ensuring food safety by using an intercropping model.


Assuntos
Agricultura , Cádmio , Lycopersicon esculentum , Poluentes do Solo , Zea mays , Agricultura/métodos , Cádmio/metabolismo , Lycopersicon esculentum/metabolismo , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/microbiologia , Poluentes do Solo/metabolismo , Zea mays/metabolismo
16.
PLoS One ; 15(4): e0232164, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32330189

RESUMO

Maize (Zea mays L) is one of main nutrients sources for humans and animals worldwide. In Africa, storage of maize ensures food resources availability throughout the year. However, it often suffers losses exceeding 20% due to insects such as the larger grain borer, Prostephanus truncatus (Horn) (Coleoptera; Bostrichidae), major pest of stored maize in the tropical countries. This study aims to select resistant varieties to reduce maize storage losses and explain the physicochemical parameters role in grains susceptibility. In the first study, maize grains were artificially infested under no-choice method with insects. Susceptibility parameters such as weight loss, grain damage, number of emerged insects, median development time and susceptibility index varied significantly through maize varieties. Dobie susceptibility index (SI) was assessed as a major indicator of resistance. The most resistant varieties were Early-Thaï, DMR-ES and Tzee-Yellow. Conversely, Synth-9243, Obatampa and Synth-C varieties were susceptible. SWAN, Across-Pool and Tzee-White were classified as moderately resistant varieties. The insect reproductive potential was significantly different in the nine maize varieties and Early-Thaï, DMR-ES and Tzee-Yellow varieties were the least favourable host. To assess the relationship between grains physicochemical characteristics and varietal susceptibility, moisture, total phenolics, palmitic acid, proteins, amylose, density and grain hardness were evaluated according to standardized methods. Palmitic acid, SI, insects emerged and grain damage were significantly and positively correlated with each other, and negatively correlated with grains hardness, phenolics and amylose contents. Maize susceptibility index was significantly and negatively correlated to amylose, and phenolics contents and positively correlated to palmitic acid content. This study identified three resistant maize varieties to P. tuncatus and revealed that the major factors involved in this resistance were hardness, phenolic and amylose contents of grains.


Assuntos
Besouros/patogenicidade , Zea mays/crescimento & desenvolvimento , Zea mays/parasitologia , África , Amilose/metabolismo , Animais , Grão Comestível/crescimento & desenvolvimento , Grão Comestível/metabolismo , Ácido Palmítico/metabolismo , Fenol/metabolismo , Estruturas Vegetais/crescimento & desenvolvimento , Estruturas Vegetais/metabolismo , Estruturas Vegetais/parasitologia , Zea mays/metabolismo
17.
PLoS Genet ; 16(4): e1007881, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32310948

RESUMO

Meiotic double-strand breaks (DSBs) are generated by the evolutionarily conserved SPO11 complex in the context of chromatin loops that are organized along axial elements (AEs) of chromosomes. However, how DSBs are formed with respect to chromosome axes and the SPO11 complex remains unclear in plants. Here, we confirm that DSB and bivalent formation are defective in maize spo11-1 mutants. Super-resolution microscopy demonstrates dynamic localization of SPO11-1 during recombination initiation, with variable numbers of SPO11-1 foci being distributed in nuclei but similar numbers of SPO11-1 foci being found on AEs. Notably, cytological analysis of spo11-1 meiocytes revealed an aberrant AE structure. At leptotene, AEs of wild-type and spo11-1 meiocytes were similarly curly and discontinuous. However, during early zygotene, wild-type AEs become uniform and exhibit shortened axes, whereas the elongated and curly AEs persisted in spo11-1 mutants, suggesting that loss of SPO11-1 compromised AE structural maturation. Our results reveal an interesting relationship between SPO11-1 loading onto AEs and the conformational remodeling of AEs during recombination initiation.


Assuntos
Endodesoxirribonucleases/metabolismo , Recombinação Homóloga , Meiose , Zea mays/citologia , Zea mays/metabolismo , Núcleo Celular/genética , Núcleo Celular/metabolismo , Pareamento Cromossômico , Quebras de DNA de Cadeia Dupla , Endodesoxirribonucleases/genética , Genes de Plantas/genética , Meiose/genética , Mutação , Fenótipo , Zea mays/genética
18.
Food Chem ; 321: 126712, 2020 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-32247179

RESUMO

Zein, a class of prolamine proteins extracted from maize, is extensively used in the food and pharmaceutical industries. Characterization of its components is essential for quality control and safety evaluation. We performed in silico digestion of zein proteins using tandem combinations of different proteinases, to improve protein sequence coverage and subsequent identification by nano-LC-MS/MS analysis. Trypsin/chymotrypsin yielded the highest protein sequence coverage of up to 79.5% and increased the number of proteins from 11 to 35 compared to trypsin/Lys-C. Besides, SDS-PAGE analysis revealed 37 proteins in the zein extract, as well as the possibility of protein polymers. Also, 420 peptides originating from 71 proteins were identified, of which 116 were predicted as bioactive by in silico approach. In conclusion, in silico prediction coupled with multi-enzyme digestion can significantly improve the coverage of complex zein protein proteome, and the potential function of zein proteins and peptides need be further investigated.


Assuntos
Excipientes/química , Peptídeos/química , Zea mays/química , Zeína/química , Sequência de Aminoácidos , Cromatografia Líquida de Alta Pressão , Excipientes/metabolismo , Peptídeos/metabolismo , Proteoma/química , Proteoma/metabolismo , Espectrometria de Massas em Tandem , Zea mays/metabolismo , Zeína/metabolismo
19.
Nat Commun ; 11(1): 1937, 2020 04 22.
Artigo em Inglês | MEDLINE | ID: mdl-32321909

RESUMO

The fiber in corn kernels, currently unutilized in the corn to ethanol process, represents an opportunity for introduction of cellulose conversion technology. We report here that Clostridium thermocellum can solubilize over 90% of the carbohydrate in autoclaved corn fiber, including its hemicellulose component glucuronoarabinoxylan (GAX). However, Thermoanaerobacterium thermosaccharolyticum or several other described hemicellulose-fermenting thermophilic bacteria can only partially utilize this GAX. We describe the isolation of a previously undescribed organism, Herbinix spp. strain LL1355, from a thermophilic microbiome that can consume 85% of the recalcitrant GAX. We sequence its genome, and based on structural analysis of the GAX, identify six enzymes that hydrolyze GAX linkages. Combinations of up to four enzymes are successfully expressed in T. thermosaccharolyticum. Supplementation with these enzymes allows T. thermosaccharolyticum to consume 78% of the GAX compared to 53% by the parent strain and increases ethanol yield from corn fiber by 24%.


Assuntos
Clostridiales/metabolismo , Técnicas de Cocultura/métodos , Etanol/metabolismo , Microbiologia Industrial/métodos , Thermoanaerobacterium/metabolismo , Zea mays/microbiologia , Celulose/metabolismo , Clostridiales/genética , Fermentação , Temperatura Alta , Thermoanaerobacterium/genética , Xilanos/metabolismo , Zea mays/metabolismo
20.
PLoS One ; 15(4): e0231764, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32348336

RESUMO

Most business-as-usual scenarios for farming under changing climate regimes project that the agriculture sector will be significantly impacted from increased temperatures and shifting precipitation patterns. Perhaps ironically, agricultural production contributes substantially to the problem with yearly greenhouse gas (GHG) emissions of about 11% of total anthropogenic GHG emissions, not including land use change. It is partly because of this tension that Climate Smart Agriculture (CSA) has attracted interest given its promise to increase agricultural productivity under a changing climate while reducing emissions. Considerable resources have been mobilized to promote CSA globally even though the potential effects of its widespread adoption have not yet been studied. Here we show that a subset of agronomic practices that are often included under the rubric of CSA can contribute to increasing agricultural production under unfavorable climate regimes while contributing to the reduction of GHG. However, for CSA to make a significant impact important investments and coordination are required and its principles must be implemented widely across the entire sector.


Assuntos
Produção Agrícola/organização & administração , Produtos Agrícolas/metabolismo , Abastecimento de Alimentos , Efeito Estufa/prevenção & controle , Cooperação Internacional , Mudança Climática , Produção Agrícola/métodos , Produção Agrícola/tendências , Tomada de Decisões Gerenciais , Gases de Efeito Estufa/efeitos adversos , Oryza/metabolismo , Solo/química , Triticum/metabolismo , Zea mays/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA