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1.
Ying Yong Sheng Tai Xue Bao ; 30(7): 2338-2344, 2019 Jul.
Artigo em Chinês | MEDLINE | ID: mdl-31418237

RESUMO

To obtain salt-alkali tolerant strains which could be potenially used to improve the quality of saline-alkali soil, soil samples collected from Dongying, Shandong Province were diluted and spread to modified Gibbson medium with pH 9 and salt concentration of 100 g·L-1. A total of 18 bacteria strains were obtained. By increasing salt concentration and pH, an extremely salt-alkali tole-rant strain N14 was screened which could grow at pH 12 and salt concentration of 20%. We analyzed the morphological, physiological and biochemical characters and 16S rDNA sequence of N14. The strain N14 was identified as Bacillus marmarensis. N14 bacterial fertilizer significantly increased the biomass of wheat, improved shoot height, fresh weight and dry weight by 21.8%, 57.9% and 41.7%, respectively. The addition of N14 bacterial fertilizer significantly increased the chlorophyll a, chlorophyll b and total chlorophyll in wheat by 36.4%, 20.0% and 31.7%, respectively. It significantly increased the activities of invertase, urease and alkaline phosphatase in saline-alkali soil by 23.2%, 68.8% and 106.5%, respectively. It also significantly increased the activities of superoxide dismutase, peroxidase and catalase in roots by 109.6%, 17.8% and 50%, respectively. The concentration of malondialdehyde in wheat roots was significantly reduced by 39.8%. This study provided an idea for the application of extreme salt-alkali tolerant bacteria and a way for improvement of saline-alkali soil.


Assuntos
Fertilizantes , Plantas Tolerantes a Sal/fisiologia , Triticum/fisiologia , Agricultura , Álcalis , Clorofila A , Solo , Microbiologia do Solo
2.
Ying Yong Sheng Tai Xue Bao ; 30(6): 1869-1876, 2019 Jun.
Artigo em Chinês | MEDLINE | ID: mdl-31257758

RESUMO

To understand the effects of organic fertilizer addition on accumulation and distribution of winter wheat assimilates, we compared organic carbon content in soil and wheat plants, photosynthetic characteristics and assimilation transformation under two different fertilizer treatments, CF (chemical fertilizer only) and OF (organic fertilizer with chemical fertilizer), using 13CO2 pulse labeling method. The results showed that OF increased soil organic carbon content and wheat photosynthetic parameters, resulting in higher organic carbon content and total dry biomass accumulation in wheat plants compared with CF treatment. Compared marking to maturity with that on the 7th day after the same marking, the content and distribution rate of 13C in leaves and stems of two treatments decreased; the 13C content in spikes increased at jointing stage and filling stage, decreased at anthesis stage, and the 13C distribution rate increased at all stages. OF treatment was more beneficial for the transportation of photosynthetic product from leaves to spikes at filling stage, with higher 13C distribution rate in spikes compared with CF treatment. The results of correlation analysis showed that dry matter accumulation was significantly positively correlated with the net input of 13C content and its distribution rate, but negatively correlated with organic carbon content in plants. The net input of 13C content was significantly positively correlated with its distribution rate, and negatively correlated with Fv/Fm and Pn. In conclusion, organic fertilizer application could increase the content of organic carbon in soil, improve wheat plants photosynthetic capacity and transportation of photosynthetic product to spikes, and ultimately increase dry matter accumulation in wheat spikes.


Assuntos
Agricultura/métodos , Fertilizantes , Triticum/fisiologia , Biomassa , Fotossíntese , Solo
3.
Plant Mol Biol ; 101(1-2): 203-220, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31297725

RESUMO

KEY MESSAGE: Here, a functional characterization of a wheat MSR has been presented: this protein makes a contribution to the plant's tolerance of abiotic stress, acting through its catalytic capacity and its modulation of ROS and ABA pathways. The molecular mechanism and function of certain members of the methionine sulfoxide reductase (MSR) gene family have been defined, however, these analyses have not included the wheat equivalents. The wheat MSR gene TaMSRA4.1 is inducible by salinity and drought stress and in this study, we demonstrate that its activity is restricted to the Met-S-SO enantiomer, and its subcellular localization is in the chloroplast. Furthermore, constitutive expression of TaMSRA4.1 enhanced the salinity and drought tolerance of wheat and Arabidopsis thaliana. In these plants constitutively expressing TaMSRA4.1, the accumulation of reactive oxygen species (ROS) was found to be influenced through the modulation of genes encoding proteins involved in ROS signaling, generation and scavenging, while the level of endogenous abscisic acid (ABA), and the sensitivity of stomatal guard cells to exogenous ABA, was increased. A yeast two-hybrid screen, bimolecular fluorescence complementation and co-immunoprecipitation assays demonstrated that heme oxygenase 1 (HO1) interacted with TaMSRA4.1, and that this interaction depended on a TaHO1 C-terminal domain. In plants subjected to salinity or drought stress, TaMSRA4.1 reversed the oxidation of TaHO1, activating ROS and ABA signaling pathways, but not in the absence of HO1. The aforementioned properties advocate TaMSRA4.1 as a candidate for plant genetic enhancement.


Assuntos
Heme Oxigenase-1/metabolismo , Metionina Sulfóxido Redutases/metabolismo , Transdução de Sinais , Estresse Fisiológico , Triticum/enzimologia , Ácido Abscísico/metabolismo , Arabidopsis/enzimologia , Arabidopsis/genética , Arabidopsis/fisiologia , Secas , Perfilação da Expressão Gênica , Heme Oxigenase-1/genética , Metionina Sulfóxido Redutases/genética , Oxirredução , Reguladores de Crescimento de Planta/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Salinidade , Tolerância ao Sal , Plântula/enzimologia , Plântula/genética , Plântula/fisiologia , Triticum/genética , Triticum/fisiologia , Técnicas do Sistema de Duplo-Híbrido
4.
Ecotoxicol Environ Saf ; 182: 109433, 2019 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-31319244

RESUMO

In order to explore the effects of pH and accompanying ions on divalent cobalt (Co(II)) toxicity to the wheat root elongation, an improved biotic ligand model (BLM) to predict Co(II) toxicity was developed in solution culture. The results showed that the Co(II)-toxicity decreased with the increases of K+, Ca2+ and Mg2+ activities, and the activity of Na+ had no impact on the Co(II)-toxicity. High H+ activity reduced the Co(II)-toxicity by the competitive effect of H+, while low H+ activity affected the toxicity by the change in the type of Co(II) in culture medium. Co2+ and CoOH+ were toxic to wheat root elongation, and Co(OH)2 was not. On the basis of BLM theory, the conditional equilibrium constants for Co2+, CoOH+, H+, Mg2+, Ca2+, K+ were obtained: logKCoBL = 4.65, logKCoOHBL = 6.62, logKHBL = 4.53, logKMgBL = 3.65, logKCaBL = 2.36 and logKKBL = 2.17. Free Co2+ and CoOH+, and the competitions of K+, Mg2+ and Ca2+ were suggested to be considered when developing the Co(II)-BLM.


Assuntos
Cobalto/toxicidade , Raízes de Plantas/efeitos dos fármacos , Poluentes do Solo/toxicidade , Triticum/efeitos dos fármacos , Cátions/farmacologia , Ligantes , Modelos Biológicos , Sódio/toxicidade , Testes de Toxicidade , Triticum/fisiologia
5.
Plant Sci ; 285: 141-150, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31203879

RESUMO

Plant tissue brittleness is related to cellular structure and lodging. MED0031 is a mutant identified previously from ethyl methane sulfonate treatment of diploid wheat accession TA2726, showing brittleness in both stem and leaf. In microscopic and histological observations, the mutant was found to have less large vascular bundles per unit area, a thinner sclerenchyma cell wall, and a broader parenchyma, compared with the wild type. The mutated gene, TmBr1, was mapped to a 0.056 cM interval on chromosome 5Am. This gene was cloned using a MapRseq approach that searched the candidate gene through combination of the prior target gene mapping information with SNP calling and discovery of differentially expressed genes from RNA_seq data of the wild type and a BC3F2 bulk showing the mutant phenotype. TmBr1 encodes a COBL protein and a nonsense mutation within the region coding for the conserved COBRA domain caused premature translation termination. Introduction of TmBr1 to Arabidopsis AtCOBL4 mutant rescued the phenotype, demonstrating their functional conservation. Apart from the effect on cellulose content, the TmBr1 mutation might modulate synthesis of noncellulosic polysaccharide pectin as well. Application of the MapRseq approach to isolation of genes present in recombination cold spots and complicated genomes was discussed.


Assuntos
Clonagem Molecular/métodos , Genes de Plantas/genética , Triticum/genética , Parede Celular/metabolismo , Celulose/metabolismo , Mapeamento Cromossômico , Genes de Plantas/fisiologia , Lignina/metabolismo , Microscopia Eletrônica de Varredura , Pectinas/metabolismo , Filogenia , Reação em Cadeia da Polimerase em Tempo Real , Triticum/anatomia & histologia , Triticum/fisiologia
6.
Plant Physiol Biochem ; 141: 154-163, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31163342

RESUMO

Different nitrogen (N) sources have been reported to significantly affect the photosynthesis (Pn) and its attributes. However, molybdenum (Mo) induced effects on photosynthetic efficacy of winter wheat under different N sources have not been investigated. A hydroponic study was carried out comprising of two winter wheat cultivars '97003' and '97014' as Mo-efficient and Mo-inefficient, respectively to underpin the effects of Mo supply (0 and 1 µM) on photosynthetic efficacy of winter wheat under different N sources (NO3̶, NH4NO3 or NH4+). The results revealed that Mo-induced increases in dry weight, gas exchange parameters, chlorophyll contents, NR activities, NO3̶ assimilation, total N contents and transcripts of TaNR and TaNRT1.1 genes under different N sources followed the trend of NH4NO3 > NO3̶ > NH4+, suggesting that Mo has more complementary effects to nitrate nutrition than sole ammonium. Interestingly, under Mo-deprivation environments, cultivar '97003' recorded more pronounced alterations in Mo-dependent parameters than '97014' cultivar. Moreover, Mo application significantly improved the chlorophyll contents and chloroplast configuration in all N sources showing that Mo has a key role in chlorophyll biosynthesis and chloroplast integrity. The results also highlighted that Mo-induced enhancements in total N contents and photosynthetic characteristics followed the same order as NH4NO3 > NO3- > NH4+, suggesting that Mo might affect Pn through N metabolism. In crux, our study findings imply that Mo supply increased Pn not only through chlorophyll synthesis and chloroplast configuration but also by N uptake and assimilation which may represent a strategy of Mo fertilizer to strengthen the photosynthetic machinery.


Assuntos
Compostos de Amônio/metabolismo , Molibdênio/farmacologia , Nitrogênio/metabolismo , Fotossíntese/efeitos dos fármacos , Triticum/fisiologia , Clorofila/metabolismo , Cloroplastos/metabolismo , Fertilizantes , Hidroponia , Microscopia Eletrônica de Transmissão , Nitratos/metabolismo , Proteínas de Plantas/metabolismo , Triticum/efeitos dos fármacos
7.
BMC Plant Biol ; 19(1): 252, 2019 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-31185903

RESUMO

BACKGROUND: Thermo-sensitive male-sterility based on Aegilops kotschyi cytoplasm (K-TCMS) plays an important role in hybrid wheat breeding. This has important possible applications in two-line hybrid wheat breeding but the genetic basis and molecular regulation mechanism related to fertility restoration are poorly understood. In this study, comparative transcriptome profiling based on RNA sequencing was conducted for two near-isogenic lines comprising KTM3315R and its sterile counterpart KTM3315A, a total of six samples (3 repetitions per group), in order to identify fertility restoration genes and their metabolic pathways. RESULTS: In total, 2642 significant differentially expressed genes (DEGs) were detected, among which 1238 were down-regulated and 1404 were up-regulated in fertile anthers. Functional annotation enrichment analysis identified important pathways related to fertility restoration, such as carbohydrate metabolism, phenylpropanoid metabolism and biosynthesis, as well as candidate genes encoding pectin methylesterase and flavanone 3-hydroxylase. Moreover, transcription factor analysis showed that a large number of DEGs were mainly involved with the WRKY, bHLH, and MYB transcription factor families. Determination of total soluble sugar and flavonoid contents demonstrated that important metabolic pathways and candidate genes are associated with fertility restoration. Twelve DEGs were selected and detected by quantitative reverse-transcribed PCR, and the results indicated that the transcriptome sequencing results were reliable. CONCLUSIONS: Our results indicate that identified DEGs were related to the fertility restoration and they proved to be crucial in Aegilops kotschyi cytoplasm. These findings also provide a basis for exploring the molecular regulation mechanism associated with wheat fertility restoration as well as screening and cloning related genes.


Assuntos
Aegilops/genética , Melhoramento Vegetal , Infertilidade das Plantas/genética , Proteínas de Plantas/genética , Transcriptoma , Triticum/genética , Citoplasma/fisiologia , Perfilação da Expressão Gênica , Redes e Vias Metabólicas/genética , Proteínas de Plantas/metabolismo , Triticum/fisiologia
8.
IET Nanobiotechnol ; 13(2): 230-236, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31051456

RESUMO

The present study was designed to check the role of silver nanoparticles (AgNPs) on physiological, biochemical parameters and antioxidants of wheat (Triticum aestivum L.) under heat stress. Plant extract of Moringa oleifera was used for AgNPs synthesis followed by characterization through UV-Vis spectroscopy, SEM, XRD and Zeta analyser. Heat stress was applied in range of 35-40°C for 3 hrs/ day for 3 days to wheat plants at trifoliate stage. Heat stress decreased the RWC (13.2%), MSI (16.3%), chl a (5.2%), chl b (4.1%) and TCCs (9.9%). Wheat plants treated with AgNPs showed significant increase in RWC (12.2%), MSI (26.5%), chl a (10%), chl b (16.4%), TCCs (19%), TPC (2.4%), TFC (2.5%), TASC (2.5%), SOD (1.3%), POX (1.5%), CAT (1.8%), APX (1.2%) and GPX (1.4%), under heat stress. Lower concentration of AgNPs (50 mg/l) decreased the sugar (5.8%) and proline contents (4%), while increase was observed in higher AgNPs concentrations. Overall, AgNPs treatment enhanced thermo-tolerance in wheat plants, but the mechanism of AgNPs action needs further investigation at genome and proteome level in wheat plants under heat stress.


Assuntos
Antioxidantes/farmacologia , Resposta ao Choque Térmico/efeitos dos fármacos , Nanopartículas Metálicas/química , Prata/farmacologia , Triticum/efeitos dos fármacos , Antioxidantes/química , Poluentes Ambientais/química , Poluentes Ambientais/farmacologia , Resposta ao Choque Térmico/fisiologia , Moringa oleifera/química , Extratos Vegetais/química , Extratos Vegetais/metabolismo , Prata/química , Superóxidos/metabolismo , Triticum/química , Triticum/metabolismo , Triticum/fisiologia
9.
Int J Mol Sci ; 20(10)2019 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-31091755

RESUMO

In this study, we generated transgenic durum wheat cv. Maali overexpressing the wheat plasma membrane aquaporin TdPIP2;1 gene under the control of PrTdPIP2;1 promoter or under the constitutive PrCaMV35S promoter. Histochemical analysis of the fusion PrTdPIP2;1::TdPIP2;1::GusA in wheat plants showed that the ß-glucuronidase (GUS) activity was detected in the leaves, stems and roots of stably transformed wheat T3 plants. Our results showed that transgenic wheat lines overexpressing the TdPIP2;1 gene exhibited improved germination rates and biomass production and retained low Na+ and high K+ concentrations in their shoots under high salt and osmotic stress conditions. In a long-term study under greenhouse conditions on salt or drought stress, transgenic TdPIP2;1 lines produced filled grains, whereas wild-type (WT) plants either died at the vegetative stage under salt stress or showed drastically reduced grain filling under drought stress. Performing real time RT-PCR experiments on wheat plants transformed with the fusion PrTdPIP2;1::GusA, we showed an increase in the accumulation of GusA transcripts in the roots of plants challenged with salt and drought stress. Study of the antioxidant defence system in transgenic wheat TdPIP2;1 lines showed that these lines induced the antioxidative enzymes Catalase (CAT) and Superoxide dismutase (SOD) activities more efficiently than the WT plants, which is associated with lower malondialdehyde and hydrogen peroxide contents. Taken together, these results indicate the high potential of the TdPIP2;1 gene for reducing water evaporation from leaves (water loss) in response to water deficit through the lowering of transpiration per unit leaf area (stomatal conductance) and engineering effective drought and salt tolerance in transgenic TdPIP2;1 lines.


Assuntos
Aquaporinas/genética , Secas , Proteínas de Plantas/genética , Tolerância ao Sal , Triticum/genética , Aquaporinas/metabolismo , Catalase/genética , Catalase/metabolismo , Germinação , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/metabolismo , Superóxido Dismutase/genética , Superóxido Dismutase/metabolismo , Triticum/metabolismo , Triticum/fisiologia , Regulação para Cima
10.
Int J Mol Sci ; 20(9)2019 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-31035313

RESUMO

Seed storage proteins must be hydrolyzed by proteases to deliver the amino acids essential for embryo growth and development. Several groups of proteases involved in this process have been identified in both the monocot and the dicot species. This review focuses on the implication of proteases during germination in two cereal species, barley and wheat, where proteolytic control during the germination process has considerable economic importance. Formerly, the participation of proteases during grain germination was inferred from reports of proteolytic activities, the expression of individual genes, or the presence of individual proteins and showed a prominent role for papain-like and legumain-like cysteine proteases and for serine carboxypeptidases. Nowadays, the development of new technologies and the release of the genomic sequences of wheat and barley have permitted the application of genome-scale approaches, such as those used in functional genomics and proteomics. Using these approaches, the repertoire of proteases known to be involved in germination has increased and includes members of distinct protease families. The development of novel techniques based on shotgun proteomics, activity-based protein profiling, and comparative and structural genomics will help to achieve a general view of the proteolytic process during germination.


Assuntos
Germinação/fisiologia , Hordeum/enzimologia , Hordeum/fisiologia , Peptídeo Hidrolases/metabolismo , Proteínas de Plantas/metabolismo , Triticum/enzimologia , Triticum/fisiologia , Regulação da Expressão Gênica de Plantas/genética , Regulação da Expressão Gênica de Plantas/fisiologia , Germinação/genética , Peptídeo Hidrolases/genética , Proteínas de Plantas/genética
11.
BMC Plant Biol ; 19(1): 193, 2019 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-31072347

RESUMO

BACKGROUND: Wheat production is largely restricted by adverse environmental stresses. Under many undesirable conditions, endoplasmic reticulum (ER) stress can be induced. However, the physiological and molecular responses of wheat to ER stress remain poorly understood. We used dithiothreitol (DTT) and tauroursodeoxycholic acid (TUDCA) to induce or suppress ER stress in wheat cells, respectively, with the aim to reveal the molecular background of ER stress responses using a combined approach of transcriptional profiling and morpho-physiological characterization. METHODS: To understand the mechanism of wheat response to ER stress, three wheat cultivars were used in our pre-experiments. Among them, the cultivar with a moderate stress tolerance, Yunong211 was used in the following experiments. We used DTT (7.5 mM) to induce ER stress and TUDCA (25 µg·mL- 1) to suppress the stress. Under three treatment groups (Control, DTT and DTT + TUDCA), we firstly monitored the morphological, physiological and cytological changes of wheat seedlings. Then we collected leaf samples from each group for RNA extraction, library construction and RNA sequencing on an Illumina Hiseq platform. The sequencing data was then validated by qRT-PCR. RESULTS: Morpho-physiological results showed DTT significantly reduced plant height and biomass, decreased contents of chlorophyll and water, increased electrolyte leakage rate and antioxidant enzymes activity, and accelerated the cell death ratio, whereas these changes were all remarkably alleviated after TUDCA co-treatment. Therefore, RNA sequencing was performed to determine the genes involved in regulating wheat response to stress. Transcriptomic analysis revealed that 8204 genes were differentially expressed in three treatment groups. Among these genes, 158 photosynthesis-related genes, 42 antioxidant enzyme genes, 318 plant hormone-related genes and 457 transcription factors (TFs) may play vital roles in regulating wheat response to ER stress. Based on the comprehensive analysis, we propose a hypothetical model to elucidate possible mechanisms of how plants adapt to environmental stresses. CONCLUSIONS: We identified several important genes that may play vital roles in wheat responding to ER stress. This work should lay the foundations of future studies in plant response to environmental stresses.


Assuntos
Estresse do Retículo Endoplasmático/genética , Regulação da Expressão Gênica de Plantas , Genes de Plantas , Transcriptoma/genética , Triticum/genética , Triticum/fisiologia , Ditiotreitol/farmacologia , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Ontologia Genética , Folhas de Planta/efeitos dos fármacos , Folhas de Planta/genética , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/genética , Reprodutibilidade dos Testes , Análise de Sequência de RNA , Ácido Tauroquenodesoxicólico/farmacologia , Fatores de Transcrição/metabolismo , Transcriptoma/efeitos dos fármacos , Triticum/anatomia & histologia
12.
Plant Physiol Biochem ; 140: 27-42, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31078782

RESUMO

Drought is one of most important limiting factors in wheat productivity worldwide. The need to increase drought tolerance during anthesis is of the utmost importance for high yield potentials and yield stability. Photosynthesis is one of the major physiological processes affected by drought. Damages in the photosynthetic apparatus may also arise due to non-regulated dissipation of excessive energy. Zinc (Zn) is an indispensable micronutrient for plants and is required for a wide range of physiological and biochemical processes. In this work we evaluated the stress mitigation effects of Zn seed priming alone and coupled with Zn foliar application in wheat plants submitted to severe drought during anthesis, followed by a recovery period. Under such severe drought stress, photosynthesis was constrained by both stomatal and non-stomatal limitation. Severe drought also induced an increase in non-regulated energy dissipation and hindered a full recovery of the plant's photosynthetic processes after rewatering. We also report possible activation of transposable elements due to drought stress and Zn application. Yield was severely decreased by drought and Zn treatments were unable to counteract this effect. Although unable to oppose the reduction of net photosynthesis, Zn treatments positively enhance photoprotection. At the end of drought period, Zn priming alone and coupled with Zn foliar application increased, respectively, over 2- and 3- fold the regulated dissipation of excess energy. Zn treatments lessened the non-regulated energy dissipation caused by drought, protected the plants against irreversible damages to the photosynthetic apparatus and enabled a better recovery of wheat plants after stress relief.


Assuntos
Secas , Triticum/fisiologia , Zinco/farmacologia , Fotossíntese/efeitos dos fármacos , Estresse Fisiológico , Triticum/efeitos dos fármacos
13.
Planta ; 250(2): 629-642, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31139926

RESUMO

MAIN CONCLUSION: Primitive wheat follows an opposite metabolic law from modern wheat with regard to leaf biomass/reproductive growth vs above-ground biomass that is under the regulation of non-hydraulic root signals and that influences resource acquisition and utilization. Non-hydraulic root signals (nHRS) are so far affirmed as a unique positive response to drying soil in wheat, and may imply huge differences in energy metabolism and source-sink relationships between primitive and modern wheat species. Using a pot-culture split-root technique to induce nHRS, four primitive wheat genotypes (two diploids and two tetraploids) and four modern wheat ones (released from different breeding decades) were compared to address the above issue. The nHRS was continuously induced in drying soil, ensuring the operation of energy metabolism under the influence of nHRS. We found that primitive wheat followed an opposite size-dependent allometric pattern (logy = αlogx + logß) in comparison with modern wheat. The relationships between ear biomass (y-axis) vs above-ground biomass (x-axis), and between reproductive biomass (y-axis) and vegetative (x-axis) biomass fell into a typical allometric pattern in primitive wheat (α > 1), and the nHRS significantly increased α (P < 0.01). However, in modern wheat, they turned to be in an isometric pattern (α ≈ 1). Regardless of nHRS, either leaf (i.e., metabolic rate) or stem biomass generally exhibited an isometric relationship with above-ground biomass in primitive wheat (α ≈ 1), while in modern wheat they fell into an allometric pattern (α > 1). Allometric scaling of specific leaf area (SLA) or biomass density showed superior capabilities of resource acquisition and utilization in modern wheat over primitive ones. We therefore proposed a generalized model to reveal how modern wheat possesses the pronounced population yield advantage over primitive wheat, and its implications on wheat domestication.


Assuntos
Transdução de Sinais , Triticum/fisiologia , Biomassa , Diploide , Domesticação , Secas , Genótipo , Folhas de Planta/genética , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/fisiologia , Raízes de Plantas/genética , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/fisiologia , Caules de Planta/genética , Caules de Planta/crescimento & desenvolvimento , Caules de Planta/fisiologia , Reprodução , Solo/química , Triticum/genética , Triticum/crescimento & desenvolvimento
14.
Int J Mol Sci ; 20(11)2019 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-31141975

RESUMO

Drought is an important abiotic stress that seriously restricts crop productivity. An understanding of drought tolerance mechanisms offers guidance for cultivar improvement. In order to understand how a well-known wheat genotype Jinmai 47 responds to drought, we adopted the iTRAQ and LC/MS approaches and conducted proteomics analysis of leaves after exposure to 20% of polyethylene glycol-6000 (PEG)-induced stress for 4 days. The study identified 176 differentially expressed proteins (DEPs), with 65 (36.5%) of them being up-regulated, and 111 (63.5%) down-regulated. DEPs, located in cellular membranes and cytosol mainly, were involved in stress and redox regulation (51), carbohydrate and energy metabolism (36), amino acid metabolism (24), and biosynthesis of other secondary metabolites (20) primarily. Under drought stress, TCA cycle related proteins were up-regulated. Antioxidant system, signaling system, and nucleic acid metabolism etc. were relatively weakened. In comparison, the metabolism pathways that function in plasma dehydration protection and protein structure protection were strongly enhanced, as indicated by the improved biosynthesis of 2 osmolytes, sucrose and Proline, and strongly up-regulated protective proteins, LEA proteins and chaperones. SUS4, P5CSs, OAT, Rab protein, and Lea14-A were considered to be important candidate proteins, which deserve to be further investigated.


Assuntos
Regulação da Expressão Gênica de Plantas , Pressão Osmótica , Proteínas de Plantas/genética , Proteoma/genética , Triticum/genética , Folhas de Planta/genética , Folhas de Planta/metabolismo , Proteínas de Plantas/metabolismo , Proteoma/metabolismo , Triticum/fisiologia
15.
Sci Total Environ ; 659: 1082-1089, 2019 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-31096323

RESUMO

The aim of the present study was to prove the long-term efficiency of the amendments zerovalent iron grit, zeolite, and Divergan® for trace metal remediation in heavily contaminated soils and to attain a recovery of microbial functionality and diversity by remediation. For immobilization of the trace metals the amendments zerovalent iron grit, natural zeolite, and Divergan® were used. Trace metal total and mobile contents were determined and bacterial communities were assessed after a SIP experiment with 13C-labelled wheat root by Ion-Torrent Sequencing targeting the bacterial 16S rRNA gene and two trace metal resistant genes for copper and cadmium (copA and czcA gene). The results show that the remediation effect of the three amendments is still stable after five years. The mobile trace metal contents were significantly (≤0.001) reduced in all treatments, except the Cu content in the zeolite treatment. A higher diversity in active metabolizing and growing soil bacteria was observed in remediated soils as compared to the non-remediated control, especially for the Divergan® treatment. The bacterial genera Kribbella, Glycomyces, Inquilinus, Nocardioides, and Lysobacter are the most significantly enriched genera in the 13C fractions of the treated samples. The occurrence of bacterial families, which could be identified carrying efflux-mediated metal resistance genes for Cd/Zn and Cu, were reduced in the remediated soils as compared to the non-remediated control. The most abundant bacterial family for the copA and the czcA gene is Xanthomonadaceae. The pH-value and the trace metal concentration could be identified as key drivers of bacterial community composition, and functions in trace metal contaminated soils and remediated soils.


Assuntos
Metais/química , Raízes de Plantas/química , Microbiologia do Solo , Poluentes do Solo/química , Triticum/química , Adaptação Fisiológica , Bactérias/metabolismo , Radioisótopos de Carbono , Metais/análise , Poluentes do Solo/análise , Triticum/microbiologia , Triticum/fisiologia
16.
BMC Plant Biol ; 19(1): 194, 2019 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-31077147

RESUMO

BACKGROUND: Our study is the first to provide RNA-Seq data analysis related to transcriptomic responses towards drought across different crops. The aim was to identify and map which genes play a key role in drought response on leaves across different crops. Forty-two RNA-seq samples were analyzed from 9 published studies in 7 plant species (Arabidopsis thaliana, Solanum lycopersicum, Zea mays, Vitis vinifera, Malus X domestica, Solanum tuberosum, Triticum aestivum). RESULTS: Twenty-seven (16 up-regulated and 11 down-regulated) drought-regulated genes were commonly present in at least 7 of 9 studies, while 351 (147 up-regulated and 204 down-regulated) were commonly drought-regulated in 6 of 9 studies. Across all kind of leaves, the drought repressed gene-ontologies were related to the cell wall and membrane re-structuring such as wax biosynthesis, cell wall organization, fatty acid biosynthesis. On the other hand, drought-up-regulated biological processes were related to responses to osmotic stress, abscisic acid, water deprivation, abscisic-activated signalling pathway, salt stress, hydrogen peroxide treatment. A common metabolic feature linked to drought response in leaves is the repression of terpenoid pathways. There was an induction of AL1 (alfin-like), UGKYAH (trihelix), WRKY20, homeobox genes and members of the SET domain family in 6 of 9 studies. Several genes involved in detoxifying and antioxidant reactions, signalling pathways and cell protection were commonly modulated by drought across the 7 species. The chromosome (Chr) mapping of these key abiotic stress genes highlighted that Chr 4 in Arabidopsis thaliana, Chr 1 in Zea mays, Chr 2 and Chr 5 in Triticum aestivum contained a higher presence of drought-related genes compared to the other remaining chromosomes. In seedling studies, it is worth notice the up-regulation of ERF4 and ESE3 (ethylene), HVA22 (abscisic acid), TIR1 (auxin) and some transcription factors (MYB3, MYB94, MYB1, WRKY53 and WRKY20). In mature leaves, ERF1 and Alfin-like 1 were induced by drought while other transcription factors (YABBY5, ARR2, TRFL2) and genes involved phospholipid biosynthesis were repressed. CONCLUSIONS: The identified and mapped genes might be potential targets of molecular breeding activities to develop cultivars with enhanced drought resistance and tolerance across different crops.


Assuntos
Cromossomos de Plantas/genética , Produtos Agrícolas/genética , Genes de Plantas/genética , Folhas de Planta/metabolismo , RNA de Plantas/genética , Arabidopsis/genética , Arabidopsis/fisiologia , Mapeamento Cromossômico , Cromossomos de Plantas/fisiologia , Desidratação , Genes de Plantas/fisiologia , Lycopersicon esculentum/genética , Lycopersicon esculentum/fisiologia , Malus/genética , Malus/fisiologia , Folhas de Planta/anatomia & histologia , RNA de Plantas/fisiologia , Solanum tuberosum/genética , Solanum tuberosum/fisiologia , Triticum/genética , Triticum/fisiologia , Vitis/genética , Vitis/fisiologia , Zea mays/genética , Zea mays/fisiologia
17.
Plant Biol (Stuttg) ; 21(5): 813-824, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30977948

RESUMO

Chilling and lodging are major threats to wheat production. However, strategies that can be used to effectively mitigate the adverse effects of these threats are still far from clear. Mechanical wounding is a traditional agronomic measure, whereas information about the role it plays in wheat chilling and lodging is scant. The aim of the present study was to investigate mechanisms underlying the protective roles of mechanical wounding in alleviating damage from chilling at jointing stage and enhancing lodging resistance after anthesis of winter wheat (Triticum aestivum L.). Our data show that net photosynthesis rate, maximum photochemical efficiency of photosystem II, activity of the antioxidant enzymes and osmolytes were significantly increased in the latest fully expanded leaves of wounded plants under chilling. Wounding also reduced hydrogen peroxide accumulation, electrolyte leakage and water loss in wounded plants. Moreover, mechanical wounding significantly reduced the length but increased the diameter and wall thickness of the basal second internode of the main stem. Quantitative and histochemical analysis further indicated that wounding increased lignin accumulation and activity of enzymes involved in lignin synthesis, which resulted in increased mechanical strength and the lodging resistance index in the main stem. We conclude from our data that mechanical wounding confers both cold tolerance by alleviating the damage caused by chilling at jointing stage and lodging resistance after anthesis of wheat plants.


Assuntos
Triticum/fisiologia , Clorofila/metabolismo , Resposta ao Choque Frio , Produção Agrícola , Fotossíntese , Complexo de Proteína do Fotossistema II/metabolismo , Caules de Planta/crescimento & desenvolvimento , Estresse Fisiológico , Triticum/crescimento & desenvolvimento , Triticum/metabolismo
18.
Pak J Biol Sci ; 22(3): 103-116, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30972980

RESUMO

BACKGROUND AND OBJECTIVE: Deficit or scarcity of water resources are considering as one of the most serious environmental phenomenon that hinder agricultural production in many countries and the present study evaluated some wheat accessions for water stress tolerance under Egyptian conditions. MATERIAL AND METHODS: Five wheat genotypes and their ten F1 crosses from half diallel analysis were tested under both levels of irrigation (normal and drought stress conditions) through estimating some agro-morphological traits in addition, determining DNA fingerprinting meanwhile using five RAPD-PCR primers. RESULTS: Final results detected that 4 parents and the best 5 F1 crosses were the most desirable genotypes for water stress tolerance depending on all results obtained for all calculated parameters under normal and water deficit treatments. CONCLUSION: Traditional breeding and DNA fingerprinting could be used to clarify and sort all genotypes to generate the best of them for water stress resistance which will be in the future as a nucleus for producing resistance wheat varieties for drought stress under Egyptian conditions.


Assuntos
Impressões Digitais de DNA , Genótipo , Estresse Fisiológico , Triticum/genética , Secas , Fenótipo , Filogenia , Melhoramento Vegetal , Polimorfismo Genético , Técnica de Amplificação ao Acaso de DNA Polimórfico , Plântula/genética , Plântula/fisiologia , Solo , Triticum/fisiologia , Água
19.
J Plant Physiol ; 237: 21-29, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30999074

RESUMO

An increase in the cellular concentration of free proline is a common response of many plants to various types of environmental stress. In this study, we monitored the accumulation of proline and the activities of Δ1-pyrroline-5-carboxylate synthetase (P5CS) and Δ1-pyrroline-5-carboxylate reductase (P5CR), the key enzymes of proline biosynthesis, in different parts of 4-day-old seedlings of wheat (Triticum aestivum L. cv. Josef) in the course of the first 8 h after the application of osmotic stress to determine the primary sites of proline production under water deficit conditions. Our results show that proline accumulated rapidly over this stress period in the root tips (cell division and elongation zone) and the basal region of the leaves in a time-dependent manner. Parallel to the rise in proline content, the activities of P5CS and P5CR increased markedly in these growing tissues under osmotic stress. Dissection of the root tip and the leaf base demonstrated that after 8 h of water shortage the accumulation of proline and the activities of P5CS and P5CR were highest in the regions where active cell division takes place. In the mature parts of the root and the leaf, there was virtually no enhancement of proline metabolism during the early phase of water deprivation investigated here. These data indicate that at the initial stage of water stress proline production is primarily required for the protection of the meristematic tissues in the roots and leaves. Furthermore, a transient rise in nitric oxide (NO) production was detected in the root tips and the leaf base in response to osmotic stress just before proline synthesis was enhanced. Treatment with the NO scavenger 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (cPTIO) reduced considerably the increase in the activities of P5CS and P5CR and suppressed the accumulation of proline by more than 85% in the stressed root tips and the leaf base. These results suggest that NO is involved as a signalling molecule in the up-regulation of proline synthesis in the growing tissues of young wheat seedlings in response to short-term water deprivation.


Assuntos
Pressão Osmótica , Prolina/biossíntese , Triticum/fisiologia , Regulação para Cima , Meristema/metabolismo , Plântula/fisiologia
20.
Plant Biol (Stuttg) ; 21(5): 825-831, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31034750

RESUMO

Accumulation of NaCl in soil causes osmotic stress in plants, and sodium (Na+ ) and chloride (Cl- ) cause ion toxicity, but also reduce the potassium (K+ ) uptake by plant roots and stimulate the K+ efflux through the cell membrane. Thus, decreased K+ /Na+ ratio in plant tissue lead us to hypothesise that elevated levels of K+ in nutrient medium enhance this ratio in plant tissue and cytosol to improve enzyme activation, osmoregulation and charge balance. In this study, wheat was cultivated at different concentrations of K+ (2.2, 4.4 or 8.8 mm) with or without salinity (1, 60 or 120 mm NaCl) and the effects on growth, root and shoot Na+ and K+ distribution and grain yield were determined. Also, the cytosolic Na+ concentration was investigated, as well as photosynthesis rate and water potential. Salinity reduced fresh weight of both shoots and roots and dry weight of roots. The grain yield was significantly reduced under Na+ stress and improved with elevated K+ fertilisation. Elevated K+ level during cultivation prevented the accumulation of Na+ into the cytosol of both shoot and root protoplasts. Wheat growth at vegetative stage was transiently reduced at the highest K+ concentration, perhaps due to plants' efforts to overcome a high solute concentration in the plant tissue, nevertheless grain yield was increased at both K+ levels. In conclusion, a moderately elevated K+ application to wheat seedlings reduces tissue as well as cytosolic Na+ concentration and enhances wheat growth and grain yield by mitigating the deleterious effects of Na+ toxicity.


Assuntos
Potássio/farmacologia , Sódio/metabolismo , Triticum/metabolismo , Pressão Osmótica , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/metabolismo , Brotos de Planta/crescimento & desenvolvimento , Brotos de Planta/metabolismo , Potássio/metabolismo , Estresse Salino , Triticum/crescimento & desenvolvimento , Triticum/fisiologia
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