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1.
BMC Plant Biol ; 19(1): 335, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31370805

RESUMO

BACKGROUND: Drought is a serious causal factor of reduced crop yields than any other abiotic stresses. As one of the most widely distributed crops, maize plants frequently suffer from drought stress, which causes great losses in the final kernel yield. Drought stress response in plants showed tissue- and developmental stage-specific characteristics. RESULTS: In this study, the ears at the V9 stage, kernels and ear leaf at the 5DAP (days after pollination) stage of maize were used for morphological, physiological and comparative transcriptomics analysis to understand the different features of "sink" or "source" organs and the effects on kernel yield under drought stress conditions. The ABA-, NAC-mediate signaling pathway, osmotic protective substance synthesis and protein folding response were identified as common drought stress response in the three organs. Tissue-specific drought stress responses and the regulators were identified, they were highly correlated with growth, physiological adaptation and yield loss under drought stress. For ears, drought stress inhibited ear elongation, led to the abnormal differentiation of the paired spikelet, and auxin signaling involved in the regulation of cell division and growth and primordium development changes. In the kernels, reduced kernel size caused by drought stress was observed, and the obvious differences of auxin, BR and cytokine signaling transduction appeared, which indicated the modification in carbohydrate metabolism, cell differentiation and growth retardation. For the ear leaf, dramatically and synergistically reduced the expression of photosynthesis genes were observed when suffered from drought stress, the ABA- and NAC- mediate signaling pathway played important roles in the regulation of photosynthesis. CONCLUSIONS: Transcriptomic changes caused by drought were highly correlated with developmental and physiological adaptation, which was closely related to the final yield of maize, and a sketch of tissue- and developmental stage-specific responses to drought stress in maize was drafted.


Assuntos
Zea mays/fisiologia , Produção Agrícola , Desidratação , Grão Comestível/crescimento & desenvolvimento , Grão Comestível/fisiologia , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas/fisiologia , Fotossíntese , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/fisiologia , Zea mays/crescimento & desenvolvimento , Zea mays/metabolismo
2.
BMC Plant Biol ; 19(1): 302, 2019 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-31291890

RESUMO

BACKGROUND: Nitrogen (N) and potassium (K) are two important mineral nutrients in regulating leaf photosynthesis. Studying the interactive effects of N and K on regulating N allocation and photosynthesis (Pn) of rice leaves will be of great significance for further increasing leaf Pn, photosynthetic N use efficiency (PNUE) and grain yield. We measured the gas exchange of rice leaves in a field experiment and tested different kinds of leaf N based on N morphology and function, and calculated the interactive effects of N and K on N allocation and the PNUE. RESULTS: Compared with N0 (0 kg N ha- 1) and K0 (0 kg K2O ha- 1) treatments, the Pn was increased by 17.1 and 12.2% with the supply of N and K. Compared with N0K0 (0 kg N and 0 kg K2O ha- 1), N0K120 (0 kg N and 120 kg K2O ha- 1) and N0K180 (0 kg N and 180 kg K2O ha- 1), N supply increased the absolute content of photosynthetic N (Npsn) by 15.1, 15.5 and 10.5% on average, and the storage N (Nstore) was increased by 32.7, 64.9 and 72.7% on average. The relative content of Npsn was decreased by 5.6, 12.1 and 14.5%, while that of Nstore was increased by 8.7, 27.8 and 33.8%. Supply of K promoted the transformation of Nstore to Npsn despite the leaf N content (Na) was indeed decreased. Compared with N0K0, N180K0 (180 kg N and 0 kg K2O ha- 1) and N270K0 (270 kg N and 0 kg K2O ha- 1), K supply increased the relative content of Npsn by 17.7, 8.8 and 7.3%, and decreased the relative content of Nstore by 24.2, 11.4 and 8.7% respectively. CONCLUSIONS: This study indicated the mechanism that K supply decreased the Na but increased the Npsn content and then increased leaf Pn and PNUE from a new viewpoint of leaf N allocation. The supply of K promoted the transformation of Nstore to Npsn and increased the PNUE. The decreased Nstore mainly resulted from the decrease of non-protein N. Combined use of N and K could optimize leaf N allocation and maintain a high leaf Npsn content and PNUE.


Assuntos
Nitrogênio/metabolismo , Oryza/fisiologia , Potássio/metabolismo , Grão Comestível/genética , Grão Comestível/crescimento & desenvolvimento , Grão Comestível/fisiologia , Oryza/genética , Oryza/crescimento & desenvolvimento , Fotossíntese , Folhas de Planta/genética , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/fisiologia
3.
BMC Plant Biol ; 19(1): 306, 2019 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-31296169

RESUMO

BACKGROUND: Phosphorus (P) deficiency in soil is a worldwide issue and a major constraint on the production of sorghum, which is an important staple food, forage and energy crop. The depletion of P reserves and the increasing price of P fertilizer make fertilizer application impractical, especially in developing countries. Therefore, identifying sorghum accessions with low-P tolerance and understanding the underlying molecular basis for this tolerance will facilitate the breeding of P-efficient plants, thereby resolving the P crisis in sorghum farming. However, knowledge in these areas is very limited. RESULTS: The 29 sorghum accessions used in this study demonstrated great variability in their tolerance to low-P stress. The internal P content in the shoot was correlated with P tolerance. A low-P-tolerant accession and a low-P-sensitive accession were chosen for RNA-seq analysis to identify potential underlying molecular mechanisms. A total of 2089 candidate genes related to P starvation tolerance were revealed and found to be enriched in 11 pathways. Gene Ontology (GO) enrichment analyses showed that the candidate genes were associated with oxidoreductase activity. In addition, further study showed that malate affected the length of the primary root and the number of tips in sorghum suffering from low-P stress. CONCLUSIONS: Our results show that acquisition of P from soil contributes to low-P tolerance in different sorghum accessions; however, the underlying molecular mechanism is complicated. Plant hormone (including auxin, ethylene, jasmonic acid, salicylic acid and abscisic acid) signal transduction related genes and many transcriptional factors were found to be involved in low-P tolerance in sorghum. The identified accessions will be useful for breeding new sorghum varieties with enhanced P starvation tolerance.


Assuntos
Fósforo/deficiência , Reguladores de Crescimento de Planta/metabolismo , Transdução de Sinais/genética , Sorghum/genética , Grão Comestível/genética , Grão Comestível/fisiologia , Perfilação da Expressão Gênica , Solo/química , Sorghum/fisiologia
4.
Chemosphere ; 227: 109-116, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30986592

RESUMO

ZnO nanoparticles (NPs) are studied as a potential solution to alleviate Zn deficiency in human diet due to their special physicochemical properties. However, information for food quality and safety in NP-treated crops is limited. The effects of ZnO NPs and ZnSO4 on germination and growth of wheat (Triticum aestivum L.) were studied in germination and pot experiments. Zn content increased significantly, ZnO NPs were more effective than ZnSO4 at increasing grain Zn content, but less effective at increasing leaf Zn, and no ZnO NPs were detected in the wheat tissues by NP-treatments, indicated by XRD. Both ZnO NPs and ZnSO4 at moderate doses increased grain yield and biomass. Compared with control, the maximum grain yield and biomass of wheat treated with ZnO NPs and ZnSO4 were increased by 56%, 63% and 55%, 72%, respectively. ZnSO4 was more toxic than ZnO NPs at high doses as measured by the inhibitory effects in seed germination, root length, shoot length and dry biomass of seedlings. Structural damage in roots and variation in enzyme activities were greater with ZnSO4 than with ZnO NPs. ZnO NPs did not cause toxicity different from that of ZnSO4, which indicates that ZnO NPs used under the current experimental conditions did not cause Nano specific risks.


Assuntos
Nanopartículas Metálicas/análise , Triticum/crescimento & desenvolvimento , Sulfato de Zinco/metabolismo , Biofortificação , Biomassa , Grão Comestível/fisiologia , Germinação/fisiologia , Folhas de Planta/química , Raízes de Plantas/fisiologia , Plântula/efeitos dos fármacos , Zinco/análise , Óxido de Zinco/química
5.
Int J Mol Sci ; 20(8)2019 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-30991628

RESUMO

Access to adequate irrigation resources is critical for sustained agricultural production, and rice, a staple cereal grain for half of the world population, is one of the biggest users of irrigation. To reduce water use, several water saving irrigation systems have been developed for rice production, but a reliable system to evaluate cultivars for water stress tolerance is still lacking. Here, seven rice cultivars that have diverse yield potential under water stress were evaluated in a field study using four continuous irrigation regimes varying from saturation to wilting point. To understand the relationship between water stress and yield potential, the physiological and leaf metabolic responses were investigated at the critical transition between vegetative and reproductive growth stages. Twenty-nine metabolite markers including carbohydrates, amino acids and organic acids were found to significantly differ among the seven cultivars in response to increasing water stress levels with amino acids increasing but organic acids and carbohydrates showing mixed responses. Overall, our data suggest that, in response to increasing water stress, rice cultivars that do not show a significant yield loss accumulate carbohydrates (fructose, glucose, and myo-inositol), and this is associated with a moderate reduction in stomatal conductance (gs), particularly under milder stress conditions. In contrast, cultivars that had significant yield loss due to water stress had the greatest reduction in gs, relatively lower accumulation of carbohydrates, and relatively high increases in relative chlorophyll content (SPAD) and leaf temperature (Tm). These data demonstrate the existence of genetic variation in yield under different water stress levels which results from a suite of physiological and biochemical responses to water stress. Our study, therefore, suggests that in rice there are different physiological and metabolic strategies that result in tolerance to water stress that should be considered in developing new cultivars for deficit irrigation production systems that use less water.


Assuntos
Grão Comestível/fisiologia , Metaboloma , Oryza/fisiologia , Solo/química , Estresse Fisiológico , Água/metabolismo , Aclimatação , Agricultura , Secas , Fotossíntese , Água/análise
6.
BMC Plant Biol ; 19(1): 126, 2019 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-30947699

RESUMO

BACKGROUND: Durum wheat is considered not suitable for making many food products that bread wheat can. This limitation is largely due to: (i) lack of grain-hardness controlling genes (Puroindoline a and b) and consequently extremely-hard kernel; (ii) lack of high- and low-molecular-weight glutenin subunit loci (Glu-D1 and Glu-D3) that contribute to gluten strength. To improve food processing quality of durum wheat, we stacked transgenic Pina and HMW-glutenin subunit 1Ax1 in durum wheat and developed lines with medium-hard kernel texture. RESULTS: Here, we demonstrated that co-expression of Pina + 1Ax1 in durum wheat did not affect the milling performance that was enhanced by Pina expression. While stacking of Pina + 1Ax1 led to increased flour yield, finer flour particles and decreased starch damage compared to the control lines. Interestingly, Pina and 1Ax1 co-expression showed synergistic effects on the pasting attribute peak viscosity. Moreover, Pina and 1Ax1 co-expression suggests that PINA impacts gluten aggregation via interaction with gluten protein matrix. CONCLUSIONS: The results herein may fill the gap of grain hardness between extremely-hard durum wheat and the soft kernel durum wheat, the latter of which has been developed recently. Our results may also serve as a proof of concept that stacking Puroindolines and other genes contributing to wheat end-use quality from the A and/or D genomes could improve the above-mentioned bottleneck traits of durum wheat and help to expand its culinary uses.


Assuntos
Glutens/genética , Triticum/genética , Pão , Grão Comestível/genética , Grão Comestível/fisiologia , Dureza , Fenótipo , Proteínas de Plantas/genética , Plantas Geneticamente Modificadas , Triticum/fisiologia
7.
Ecotoxicol Environ Saf ; 174: 637-648, 2019 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-30875557

RESUMO

Gamma irradiation has been reported to modulate the biochemical and molecular parameters associated with the tolerance of plant species under biotic/ abiotic stress. Wheat is highly sensitive to heat stress (HS), as evident from the decrease in the quantity and quality of the total grains. Here, we studied the effect of pre-treatment of wheat dry seeds with different doses of gamma irradiation (0.20, 0.25 and 0.30 kGy) on tolerance level and quality of developing wheat endospermic tissue under HS (38 °C, 1 h; continuously for three days). Expression analysis of genes associated with defence and starch metabolism in developing grains showed maximum transcripts of HSP17 (in response to 0.25 kGy + HS) and AGPase (under 0.30 kGy), as compared to control. Gamma irradiation was observed to balance the accumulation of H2O2 by enhancing the activities of SOD and GPx in both the cvs. under HS. Gamma irradiation was observed to stabilize the synthesis of starch and amylose by regulating the activities of AGPase, SSS and α-amylase under HS. The appearance of isoforms of gliadins (α, ß, γ, ω) were observed more in gamma irradiated seeds (0.20 kGy), as compared to control. Gamma irradiation (0.25 kGy in HD3118 & 0.20 kGy in HD3086) was observed to have positive effect on the width, length and test seed weight of the grains under HS. The information generated in present investigation provides easy, cheap and user-friendly technology to mitigate the effect of terminal HS on the grain-development process of wheat along with development of robust seeds with high nutrient density.


Assuntos
Grão Comestível/efeitos da radiação , Endosperma/efeitos da radiação , Raios gama , Estresse Oxidativo/efeitos da radiação , Triticum , Grão Comestível/enzimologia , Grão Comestível/fisiologia , Endosperma/enzimologia , Endosperma/fisiologia , Irradiação de Alimentos , Resposta ao Choque Térmico/efeitos da radiação , Peróxido de Hidrogênio/metabolismo , Sementes/enzimologia , Sementes/fisiologia , Sementes/efeitos da radiação , Amido/biossíntese
8.
Int J Mol Sci ; 20(4)2019 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-30781763

RESUMO

Salinity is an ever-present major constraint and a major threat to legume crops, particularly in areas with irrigated agriculture. Legumes demonstrate high sensitivity, especially during vegetative and reproductive phases. This review gives an overview of legumes sensitivity to salt stress (SS) and mechanisms to cope with salinity stress under unfavorable conditions. It also focuses on the promising management approaches, i.e., agronomic practices, breeding approaches, and genome editing techniques to improve performance of legumes under SS. Now, the onus is on researchers to comprehend the plants physiological and molecular mechanisms, in addition to various responses as part of their stress tolerance strategy. Due to their ability to fix biological nitrogen, high protein contents, dietary fiber, and essential mineral contents, legumes have become a fascinating group of plants. There is an immense need to develop SS tolerant legume varieties to meet growing demand of protein worldwide. This review covering crucial areas ranging from effects, mechanisms, and management strategies, may elucidate further the ways to develop SS-tolerant varieties and to produce legume crops in unfavorable environments.


Assuntos
Grão Comestível/fisiologia , Fabaceae/fisiologia , Estresse Salino/fisiologia , Antioxidantes/metabolismo , Modelos Biológicos , Salinidade
9.
Methods Mol Biol ; 1931: 87-108, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30652285

RESUMO

Sorghum (Sorghum bicolor L. Moench) is a major drought-tolerant cereal crop grown mainly in the semi-arid regions of the world. It is an important basic food cereal in these regions which encompasses most of the developing world in many parts of Africa and Asia. Therefore, sorghum is an important source of nutrients for millions of inhabitants in these regions. In light of this, the nutritional quality of sorghum and how this is assessed is of major research interest. Various assays have been used to determine the contents of macronutrients and micronutrients in sorghum including how digestible and bioaccessible these are. A wide range of indices of sorghum nutritional quality has been generated. Advances in analytical instrumentation have contributed significantly to enhancing the capacity of analysts and researchers to broaden the scope of assays for sorghum nutritional quality and also to improve their accuracy.


Assuntos
Valor Nutritivo/fisiologia , Sorghum/fisiologia , África , Ásia , Secas , Grão Comestível/fisiologia
10.
Ecotoxicol Environ Saf ; 171: 701-708, 2019 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-30658306

RESUMO

Tropospheric ozone (O3) has been identified as the most damaging air pollutant to crop plants in terms of growth and yield reductions. Considering the negative effect of O3 in tropical regions, fourteen commonly grown Indian wheat cultivars with known sensitivity to O3 were tested for their sensitivity/tolerance with respect to two major antioxidants (ascorbic acid and thiols) and grain yield responses against elevated O3 (ambient + 30 ppb) exposure. The objectives of the study were to assess the usefulness of the biochemical markers in the screening of wheat cultivars having differential level of sensitivity to O3 and different release time (modern and old cultivars). Ozone exposure led to an upsurge of ascorbic acid, thiols as well as their ratio greatly in the tolerant group followed by the intermediately sensitive group while least in sensitive one. Both ascorbic acid and thiol contents offered more resistance to early released cultivars compared to modern ones. Ascorbic acid served to be the most influential parameter for determining varietal response under elevated O3 stress and directly linked with O3 tolerance. Overall, the sensitive group suffered maximum yield losses while the minimum was observed in the tolerant group due to the differential enhancement of tolerance offered by antioxidants. Higher concentrations of antioxidants at early growth stages were highly correlated with final yield responses suggesting the role of antioxidants as a determinant of final yield. Findings of this study will help in the identification of O3 tolerant and sensitive wheat cultivars for future screening programs using ascorbic acid and thiols as important markers of O3 tolerance.


Assuntos
Poluentes Atmosféricos/toxicidade , Ácido Ascórbico/metabolismo , Ozônio/toxicidade , Compostos de Sulfidrila/metabolismo , Triticum/efeitos dos fármacos , Biomarcadores/metabolismo , Grão Comestível/efeitos dos fármacos , Grão Comestível/fisiologia , Monitoramento Ambiental , Folhas de Planta/efeitos dos fármacos , Folhas de Planta/fisiologia , Triticum/fisiologia
11.
J Agric Food Chem ; 66(34): 8887-8897, 2018 Aug 29.
Artigo em Inglês | MEDLINE | ID: mdl-30075073

RESUMO

Grain quality and composition in food legumes are influenced by abiotic stresses. This review discusses the influence of abiotic stresses on grain composition and quality in food grains. Grain protein declines under salt stress due to the restricted absorption of nitrate from the soil solution. Grain phosphorus, nitrogen, and potassium contents declined whereas sodium and chloride increased. However, under drought, grain protein increased whereas the oil contents were decreased. For example, among fatty acids, oleic acid content increased; however, linoleic and/or linolenic acids were decreased under drought. Heat stress increased grain oil content whereas grain protein was decreased. Low temperature during late pod-filling reduced starch, protein, soluble sugar, fat, and fiber contents. However, an elevated CO2 level improved omega-3 fatty acid content at the expense of omega-6 fatty acids. Crop management and improvement strategies, next generation sequencing, and gene manipulation can help improve quality of food legumes under abiotic stresses.


Assuntos
Fabaceae/fisiologia , Sementes/química , Secas , Grão Comestível/química , Grão Comestível/fisiologia , Fabaceae/química , Ácidos Graxos/análise , Proteínas de Plantas/análise , Controle de Qualidade , Sementes/fisiologia , Amido/análise , Estresse Fisiológico
12.
Planta ; 248(5): 1263-1275, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30099651

RESUMO

MAIN CONCLUSION: Vacuolar compartments being sustained among the amyloplasts inadequately accumulated in rice endosperm cells are the main cause of chalky ring formation under dry wind conditions. Foehn-induced dry wind during the grain-filling stage induces shoot water deficit in rice (Oryza sativa L.) plants, which form a ring-shaped chalkiness in their endosperm that degrades milling quality and rice appearance. Air spaces formed in several inner cells cause significant transparency loss due to irregular light reflection. Although starch synthesis was suggested to be retarded by osmotic adjustment at foehn-induced moderately low water potential, the source of these air spaces remains unknown. We hypothesised that the preservation of vacuoles accompanied by a temporary reduction in starch biosynthesis in the inner cells leads to the chalky ring formation. Panicle water status measurement, light and transmission electron microscopic (TEM) observations, and an absolute qPCR analysis were conducted. Most starch synthesis-related genes exhibited temporarily reduced expression in the inner zone in accordance with the decrease in panicle water status. TEM observations provided evidence that vacuolar compartments remained among the loosely packed starch granules in the inner endosperm cells, where a chalky ring appeared after kernel dehydration. Taken together, we propose that vacuolar compartments sustained among the amyloplasts inadequately accumulated in rice endosperm cells and caused air space formation that leads to ring-shaped chalkiness under dry wind conditions.


Assuntos
Grão Comestível/ultraestrutura , Oryza/ultraestrutura , Vacúolos/ultraestrutura , Vento , Desidratação , Grão Comestível/metabolismo , Grão Comestível/fisiologia , Endosperma/metabolismo , Expressão Gênica , Perfilação da Expressão Gênica , Microscopia , Oryza/metabolismo , Oryza/fisiologia , Doenças das Plantas/etiologia , Amido/metabolismo , Vacúolos/fisiologia
13.
PLoS One ; 13(4): e0195535, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29630647

RESUMO

The occurrence of water stress during wheat growth is more frequent due to climate change. Three experiments (cyclic drought, cyclic waterlogging, and cyclic drought plus waterlogging) were conducted to investigate the effects of mild and severe cyclic/single water stress at elongation and heading stages on winter wheat (Triticum aestivum L.) yield. The effect of either mild drought at elongation or mild waterlogging at heading on wheat yield was not significant; however, significance did occur under other single water stresses. As the stress becomes more severe, the yield loss significantly increases. Extreme drought/waterlogging treatment at elongation caused a greater yield penalty than stress at heading stage. Except the combination of mild drought and mild waterlogging treatment, cyclic water stress significantly decreased wheat yields. The decrease in wheat yield under cyclic severe drought and waterlogging was significantly higher than any other treatment, with percentage decreases of 71.52 and 73.51%, respectively. In general, a yield reduction from mild cyclic water stress did not indicate more severe damage than single treatments; in contrast, grain yield suffered more when water stress occurred again after severe drought and waterlogging. Drought during elongation significantly decreased kernel number, whereas drought at heading/waterlogging during elongation and heading decreased the spike weight, which might be the main reason for the yield penalty. Furthermore, water stress caused variation in the decrease of total biomass and/or harvest index. The present study indicates comprehensive understanding of the types, degree, and stages of water stress are essential for assessing the impact of multiple water stresses on wheat yield.


Assuntos
Mudança Climática , Desidratação , Triticum/crescimento & desenvolvimento , Triticum/fisiologia , Biomassa , China , Secas , Grão Comestível/crescimento & desenvolvimento , Grão Comestível/fisiologia , Chuva , Estações do Ano , Água/metabolismo
14.
Plant Sci ; 270: 114-122, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29576063

RESUMO

The chloride concentration in the plant determines yield and quality formation for two reasons. First, chlorine is a mineral nutrient and deficiencies thereof induce metabolic problems that interfere with growth. However, due to low requirement of most crops, deficiency of chloride hardly appears in the field. Second, excess of chloride, an event that occurs under chloride-salinity, results in severe physiological dysfunctions impairing both quality and yield formation. The chloride ion can effect quality of plant-based products by conferring a salty taste that decreases market appeal of e.g. fruit juices and beverages. However, most of the quality impairments are based on physiological dysfunctions that arise under conditions of chloride-toxicity: Shelf life of persimmon is shortened due to an autocatalytic ethylene production in fruit tissues. High concentrations of chloride in the soil can increase phyto-availability of the heavy metal cadmium, accumulating in wheat grains above dietary intake thresholds. When crops are cultivated on soils that are moderately salinized by chloride, nitrate fertilization might be a strategy to suppress uptake of chloride by means of an antagonistic anion-anion uptake competition. Overall, knowledge about proteins that catalyse chloride-efflux out of the roots or that restrict xylem loading is needed to engineer more resistant crops.


Assuntos
Cloretos/metabolismo , Cloro/metabolismo , Produtos Agrícolas/efeitos dos fármacos , Doenças das Plantas/prevenção & controle , Cádmio/metabolismo , Cloretos/toxicidade , Produtos Agrícolas/crescimento & desenvolvimento , Produtos Agrícolas/fisiologia , Diospyros/efeitos dos fármacos , Diospyros/crescimento & desenvolvimento , Diospyros/fisiologia , Grão Comestível/efeitos dos fármacos , Grão Comestível/crescimento & desenvolvimento , Grão Comestível/fisiologia , Etilenos/metabolismo , Qualidade dos Alimentos , Frutas/efeitos dos fármacos , Frutas/crescimento & desenvolvimento , Frutas/fisiologia , Osmorregulação , Fotossíntese , Doenças das Plantas/microbiologia , Reguladores de Crescimento de Planta/metabolismo , Salinidade , Solanum tuberosum/efeitos dos fármacos , Solanum tuberosum/crescimento & desenvolvimento , Solanum tuberosum/fisiologia , Triticum/efeitos dos fármacos , Triticum/crescimento & desenvolvimento , Triticum/fisiologia
15.
PLoS One ; 13(3): e0194075, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29518125

RESUMO

Grain number is a major trait for wheat yield under dryland farming. An International Triticeae Mapping Initiative (ITMI) mapping population comprising 105 recombinant inbred lines (RIL) developed from a cross between a Synthetic hexaploid wheat (Triticum aestivum) 'W7984' and a spring wheat variety 'Opata M85' was used to identify quantitative trait loci (QTL) associated with grain number per spike under two treatment conditions, normal watering and water stress during meiosis. Two major QTL for grain number per spike on the main stem Q.Gnu.uwa-5A-1 and Q.Gnu.uwa-5A-2 with phenotypic variations of 25.71% and 24.93%, respectively, were detected on the long arm of chromosome 5A when plants were exposed to water stress during meiosis. One QTL (Q.Gnu.uwa-2A) with a LOD score of 2.8 was detected on the long arm of chromosome 2A under normal watering condition. The alleles associated with higher grain number per spike under different treatment conditions came from the Synthetic W7984 parent. Two populations developed from crosses Synthetic W7984 × Lang and Synthetic W7984 × Westonia were used to validate the identified QTL under water stress during meiosis. SSR markers Xbarc230 and Xbarc319 linked with the identified QTL on chromosome 5AL were validated in the two F2:4 segregating populations. These closely linked SSR markers could potentially be utilized in marker-assisted selection to reduce yield loss in regions where water stress during meiosis occurs frequently. The identified QTL can be incorporated into elite lines / cultivars to improve wheat grain yield.


Assuntos
Irrigação Agrícola , Cromossomos de Plantas/genética , Grão Comestível/genética , Triticum/genética , Segregação de Cromossomos , Cruzamentos Genéticos , DNA de Plantas/genética , Desidratação , Grão Comestível/fisiologia , Escore Lod , Meiose , Fenótipo , Melhoramento Vegetal , Folhas de Planta/química , Locos de Características Quantitativas , Característica Quantitativa Herdável , Sementes , Estresse Fisiológico/genética , Triticum/fisiologia , Água
16.
Phytopathology ; 108(1): 124-132, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29063821

RESUMO

An in vitro spike culture method was optimized to evaluate Fusarium head blight (FHB) resistance in wheat (Triticum aestivum) and used to screen a population of ethyl methane sulfonate treated spike culture-derived variants (SCDV). Of the 134 SCDV evaluated, the disease severity score of 47 of the variants was ≤30%. Single nucleotide polymorphisms (SNP) in the UDP-glucosyltransferase (UGT) genes, TaUGT-2B, TaUGT-3B, and TaUGT-EST, differed between AC Nanda (an FHB-susceptible wheat variety) and Sumai-3 (an FHB-resistant wheat cultivar). SNP at 450 and 1,558 bp from the translation initiation site in TaUGT-2B and TaUGT-3B, respectively were negatively correlated with FHB severity in the SCDV population, whereas the SNP in TaUGT-EST was not associated with FHB severity. Fusarium graminearum strain M7-07-1 induced early expression of TaUGT-2B and TaUGT-3B in FHB-resistant SCDV lines, which were associated with deoxynivalenol accumulation and reduced FHB disease progression. At 8 days after inoculation, deoxynivalenol concentration varied from 767 ppm in FHB-resistant variants to 2,576 ppm in FHB-susceptible variants. The FHB-resistant SCDV identified can be used as new sources of FHB resistance in wheat improvement programs.


Assuntos
Fusarium/fisiologia , Genoma de Planta/genética , Glucosiltransferases/genética , Doenças das Plantas/imunologia , Polimorfismo de Nucleotídeo Único/genética , Tricotecenos/metabolismo , Triticum/genética , Resistência à Doença/genética , Grão Comestível/enzimologia , Grão Comestível/genética , Grão Comestível/microbiologia , Grão Comestível/fisiologia , Glucosiltransferases/metabolismo , Doenças das Plantas/microbiologia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Triticum/enzimologia , Triticum/microbiologia , Triticum/fisiologia
17.
BMC Plant Biol ; 17(Suppl 1): 181, 2017 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-29143605

RESUMO

BACKGROUND: Alike to Reduced height-1 (Rht-1) genes in wheat and the semi dwarfing (sd-1) gene in rice, the sdw1/denso locus involved in the metabolism of the GA, was designated as the 'Green Revolution' gene in barley. The recent molecular characterization of the candidate gene HvGA20ox2 for sdw1/denso locus allows to estimate the impact of the functional polymorphism of this gene on the variation of agronomically important traits in barley. RESULTS: We investigated the effect of the 7-bp deletion in exon 1 of HvGA20ox2 gene (sdw1.d mutation) on the variation of yield-related and malting quality traits in the population of DHLs derived from cross of medium tall barley Morex and semi-dwarf barley Barke. Segregation of plant height, flowering time, thousand grain weight, grain protein content and grain starch was evaluated in two diverse environments separated from one another by 15° of latitude. The 7-bp deletion in HvGA20ox2 gene reduced plant height by approximately 13 cm and delayed flowering time by 3-5 days in the barley segregating DHLs population independently on environmental cue. On other hand, the sdw1.d mutation did not affect significantly either grain quality traits (protein and starch content) or thousand grain weight. CONCLUSIONS: The beneficial effect of the sdw1.d allele could be associated in barley with lodging resistance and extended period of vegetative growth allowing to accumulate additional biomass that supports higher yield in certain environments. However, no direct effect of the sdw1.d mutation on thousand grain weight or grain quality traits in barley was detected.


Assuntos
Genes de Plantas , Hordeum/genética , Oxigenases de Função Mista/genética , Deleção de Sequência , Mapeamento Cromossômico , Cromossomos de Plantas , DNA de Plantas , Grão Comestível/genética , Grão Comestível/fisiologia , Hordeum/química , Hordeum/enzimologia , Fenótipo , Melhoramento Vegetal , Polimorfismo Genético , Locos de Características Quantitativas , Sementes/química , Sementes/genética , Análise de Sequência de DNA , Amido/análise
18.
J Exp Bot ; 68(18): 5233-5245, 2017 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-29106621

RESUMO

Rice grain yield and quality are predicted to be highly vulnerable to global warming. Five genotypes including heat-tolerant and susceptible checks, a heat-tolerant near-isogenic line and two hybrids were exposed to control (31 °C/23 °C, day/night), high night-time temperature (HNT; 31 °C/30 °C), high day-time temperature (HDT; 38 °C/23 °C) and high day- and night-time temperature (HNDT; 38 °C/30 °C) treatments for 20 consecutive days during the grain-filling stage. Grain-filling dynamics, starch metabolism enzymes, temporal starch accumulation patterns and the process of chalk formation were quantified. Compensation between the rate and duration of grain filling minimized the impact of HNT, but irreversible impacts on seed-set, grain filling and ultimately grain weight were recorded with HDT and HNDT. Scanning electron microscopy demonstrated irregular and smaller starch granule formation affecting amyloplast build-up with HDT and HNDT, while a quicker but normal amylopast build-up was recorded with HNT. Our findings revealed temporal variation in the starch metabolism enzymes in all three stress treatments. Changes in the enzymatic activity did not derail starch accumulation under HNT when assimilates were sufficiently available, while both sucrose supply and the conversion of sucrose into starch were affected by HDT and HNDT. The findings indicate differential mechanisms leading to high day and high night temperature stress-induced loss in yield and quality. Additional genetic improvement is needed to sustain rice productivity and quality under future climates.


Assuntos
Oryza/crescimento & desenvolvimento , Amido/metabolismo , Biomassa , Grão Comestível/genética , Grão Comestível/crescimento & desenvolvimento , Grão Comestível/fisiologia , Genótipo , Temperatura Alta , Oryza/genética , Oryza/fisiologia , Sementes/genética , Sementes/crescimento & desenvolvimento , Sementes/fisiologia , Temperatura Ambiente
19.
Trends Plant Sci ; 22(10): 880-893, 2017 10.
Artigo em Inglês | MEDLINE | ID: mdl-28843766

RESUMO

The spectacular yield increases in rice and wheat during the green revolution were partly realized by reduced gibberellin (GA) synthesis or sensitivity, both causing the accumulation of DELLA proteins. Although insights into the regulation of plant growth and development by DELLA proteins advanced rapidly in arabidopsis (Arabidopsis thaliana), DELLA-mediated regulation of downstream responses in cereals has received little attention to date. Furthermore, translating this research from arabidopsis to cereals is challenging given their different growth patterns and our phylogenetic analysis which reveals that DELLA-related DGLLA proteins exist in cereals but not in arabidopsis. Therefore, understanding the molecular basis of DELLA function in cereals holds great potential to improve yield. In this review, we propose to extend the focus of DELLA functional research to cereals, and highlight the appropriate tools that are now available to achieve this.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/genética , Transdução de Sinais , Arabidopsis/fisiologia , Proteínas de Arabidopsis/genética , Grão Comestível/genética , Grão Comestível/fisiologia , Giberelinas/metabolismo , Filogenia , Reguladores de Crescimento de Planta/metabolismo
20.
Planta ; 246(6): 1097-1107, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28801748

RESUMO

MAIN CONCLUSION: The expression of a barley alanine aminotransferase gene impacts agronomic outcomes in a C3 crop, wheat. The use of nitrogen-based fertilizers has become one of the major agronomic inputs in crop production systems. Strategies to enhance nitrogen assimilation and flux in planta are being pursued through the introduction of novel genetic alleles. Here an Agrobacterium-mediated approach was employed to introduce the alanine aminotransferase from barley (Hordeum vulgare), HvAlaAT, into wheat (Triticum aestivum) and sorghum (Sorghum bicolor), regulated by either constitutive or root preferred promoter elements. Plants harboring the transgenic HvAlaAT alleles displayed increased alanine aminotransferase (alt) activity. The enhanced alt activity impacted height, tillering and significantly boosted vegetative biomass relative to controls in wheat evaluated under hydroponic conditions, where the phenotypic outcome across these parameters varied relative to time of year study was conducted. Constitutive expression of HvAlaAT translated to elevation in wheat grain yield under field conditions. In sorghum, expression of HvAlaAT enhanced enzymatic activity, but no changes in phenotypic outcomes were observed. Taken together these results suggest that positive agronomic outcomes can be achieved through enhanced alt activity in a C3 crop, wheat. However, the variability observed across experiments under greenhouse conditions implies the phenotypic outcomes imparted by the HvAlaAT allele in wheat may be impacted by environment.


Assuntos
Alanina Transaminase/metabolismo , Hordeum/enzimologia , Nitrogênio/metabolismo , Sorghum/fisiologia , Triticum/enzimologia , Agrobacterium/fisiologia , Alanina Transaminase/genética , Grão Comestível/enzimologia , Grão Comestível/genética , Grão Comestível/fisiologia , Hordeum/genética , Fenótipo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Raízes de Plantas/enzimologia , Raízes de Plantas/genética , Raízes de Plantas/fisiologia , Plantas Geneticamente Modificadas , Regiões Promotoras Genéticas/genética , Sorghum/genética , Transgenes , Triticum/genética , Triticum/fisiologia
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