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1.
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
2.
BMC Plant Biol ; 19(1): 242, 2019 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-31174465

RESUMO

BACKGROUND: Recurrent drought associated with climate change is a major constraint to wheat (Triticum aestivum L.) productivity. This study aimed to (i) quantify the effects of addition/substitution/translocation of chromosome segments from wild relatives of wheat on the root, physiological and yield traits of hexaploid wheat under drought, and (ii) understand the mechanism(s) associated with drought tolerance or susceptibility in wheat-alien chromosome lines. METHODS: A set of 48 wheat-alien chromosome lines (addition/substitution/translocation lines) with Chinese Spring background were used. Seedling root traits were studied on solid agar medium. To understand the influence of drought on the root system of adult plants, these 48 lines were grown in 150-cm columns for 65 d under full irrigation or withholding water for 58 d. To quantify the effect of drought on physiological and yield traits, the 48 lines were grown in pots under full irrigation until anthesis; after that, half of the plants were drought stressed by withholding water for 16 d before recording physiological and yield-associated traits. RESULTS: The alien chromosome lines exhibited altered root architecture and decreased photochemical efficiency and seed yield and its components under drought. The wheat-alien chromosome lines T5DS·5S#3L (TA5088) with a chromosome segment from Aegilops speltoides (5S) and T5DL.5 V#3S (TA5638) with a chromosome segment from Dasypyrum villosum (5 V) were identified as drought tolerant, and the drought tolerance mechanism was associated with a deep, thin and profuse root system. CONCLUSIONS: The two germplasm lines (TA5088 and TA5638) could be used in wheat breeding programs to improve drought tolerance in wheat and understand the underlying molecular genetic mechanisms of root architecture and drought tolerance.


Assuntos
Cromossomos de Plantas/genética , Secas , Genes de Plantas/genética , Melhoramento Vegetal , Triticum/genética , Aegilops/genética , Raízes de Plantas/anatomia & histologia , Raízes de Plantas/genética , Raízes de Plantas/crescimento & desenvolvimento , Poaceae/genética , Triticum/anatomia & histologia , Triticum/crescimento & desenvolvimento
3.
BMC Plant Biol ; 19(1): 175, 2019 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-31046676

RESUMO

BACKGROUND: DUOII is a multi-ovary wheat (Triticum aestivum L.) line with two or three pistils and three stamens in each floret. The multi-ovary trait of DUOII is controlled by a dominant gene, whose expression can be suppressed by the heterogeneous cytoplasm of TeZhiI (TZI), a line with the nucleus of common wheat and the cytoplasm of Aegilops. Crosses between female DUOII plants and male TZI plants resulted in multi-ovary F1s; whereas, the reciprocal crosses resulted in mono-ovary F1s. Although the multi-ovary trait is inherited as single trait controlled by a dominant allele in lines with a Triticum cytoplasm, the mechanism by which the special heterogeneous cytoplasm suppresses the expression of multi-ovary is not well understood. RESULTS: Observing the developmental process, we found that the critical stage of additional pistil primordium development was when the young spikes were 2-6 mm long. Then, we compared the quantitative proteomic profiles of 2-6 mm long young spikes obtained from the reciprocal crosses between DUOII and TZI. A total of 90 differentially expressed proteins were identified and analyzed based on their biological functions. These proteins had obvious functional pathways mainly implicated in chloroplast metabolism, nuclear and cell division, plant respiration, protein metabolism, and flower development. Importantly, we identified two key proteins, Flowering Locus K Homology Domain and PEPPER, which are known to play an essential role in the specification of pistil organ identity. By drawing relationships between the 90 differentially expressed proteins, we found that these proteins revealed a complex network which is associated with multi-ovary gene expression under heterogeneous cytoplasmic suppression. CONCLUSIONS: Our proteomic analysis has identified certain differentially expressed proteins in 2-6 mm long young spikes, which was the critical stage of additional primordium development. This paper provided a universal proteomic profiling involved in the cytoplasmic suppression of wheat floral meristems; and our findings have laid a solid foundation for further mechanistic studies on the underlying mechanisms that control the heterogeneous cytoplasm-induced suppression of the nuclear multi-ovary gene in wheat.


Assuntos
Citoplasma/metabolismo , Triticum/metabolismo , Cruzamentos Genéticos , Flores/anatomia & histologia , Flores/genética , Flores/crescimento & desenvolvimento , Regulação da Expressão Gênica de Plantas , Fenótipo , Proteínas de Plantas/genética , Proteínas de Plantas/fisiologia , Proteômica , Triticum/anatomia & histologia , Triticum/genética
4.
Molecules ; 24(9)2019 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-31075937

RESUMO

The conversion of organic wastes into biochar via the pyrolysis technique could be used to produce soil amendments useful as a source of plant nutrients. In this study, we investigated the effects of fruit peels and milk tea waste-derived biochars on wheat growth, yield, root traits, soil enzyme activities and nutrient status. Eight amendment treatments were tested: no amendment (CK), chemical fertilizer (CF), banana peel biochar 1% (BB1 + CF), banana peel biochar 2% (BB2 + CF), orange peel biochar 1% (OB1 + CF), orange peel biochar 2% (OB2 + CF), milk tea waste biochar 1% (TB1 + CF) and milk tea waste biochar 2% (TB2 + CF). The results indicated that chlorophyll values, plant height, grain yield, dry weight of shoot and root were significantly (p < 0.05) increased for the TB2 + CF treatment as compared to other treatments. Similarly, higher contents of nutrients in grains, shoots and roots were observed for TB2 + CF: N (61.3, 23.3 and 7.6 g kg-1), P (9.2, 10.4 and 8.3 g kg-1) and K (9.1, 34.8 and 4.4 g kg-1). Compared to CK, the total root length (41.1%), surface area (56.5%), root volume (54.2%) and diameter (78.4%) were the greatest for TB2 + CF, followed by BB2 + CF, OB2 + CF, TB1 + CF, BB1 + CF, OB1 + CF and CF, respectively. However, BB + CF and OB + CF treatments increased ß-glucosidase and dehydrogenase, but not urease activity, as compared to the TB + CF amendment, while all enzyme activity decreased with the increased biochar levels. We concluded that the conversion of fruit peels and milk tea waste into biochar products contribute the benefits of environmental and economic issues, and should be tested as soil amendments combined with chemical fertilizers for the improvement of wheat growth and grain yield as well as soil fertility status under field conditions.


Assuntos
Carvão Vegetal/farmacologia , Argila/química , Solo/química , Triticum/crescimento & desenvolvimento , Carbono/análise , Fertilizantes , Concentração de Íons de Hidrogênio , Nitrogênio/análise , Compostos Orgânicos/análise , Fósforo/análise , Raízes de Plantas/química , Brotos de Planta/química , Potássio/análise , Análise de Componente Principal , Sementes/química , Triticum/anatomia & histologia
5.
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
6.
PLoS One ; 14(4): e0214145, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30947257

RESUMO

Root growth angle (RGA) in response to gravity controlled by auxin is a pertinent target trait for obtainment of higher yield in cereals. But molecular basis of this root architecture trait remain obscure in wheat and barley. We selected four cultivars two each for wheat and barley to unveil the molecular genetic mechanism of Deeper Rooting 1-like gene which controls RGA in rice leading to higher yield under drought imposition. Morphological analyses revealed a deeper and vertically oriented root growth in "NARC 2009" variety of wheat than "Galaxy" and two other barley cultivars "Scarlet" and "ISR42-8". Three new homoeologs designated as TaANDRO1-like, TaBNDRO1-like and TaDNDRO1-like corresponding to A, B and D genomes of wheat could be isolated from "NARC 2009". Due to frameshift and intronization/exonization events the gene structures of these paralogs exhibit variations in size. DRO1-like genes with five distinct domains prevail in diverse plant phyla from mosses to angiosperms but in lower plants their differentiation from LAZY, NGR and TAC1 (root and shoot angle genes) is enigmatic. Instead of IGT as denominator motif of this family, a new C-terminus motif WxxTD in the V-domain is proposed as family specific motif. The EAR-like motif IVLEM at the C-terminus of the TaADRO1-like and TaDDRO1-like that diverged to KLHTLIPNK in TaBDRO1-like and HvDRO1-like is the hallmark of these proteins. Split-YFP and yeast two hybrid assays complemented the interaction of TaDRO1-like with TOPLESS-a repressor of auxin regulated root promoting genes in plants-through IVLEM/KLHTLIPNK motif. Quantitative RT-PCR revealed abundance of DRO1-like RNA in root tips and spikelets while transcript signals were barely detectable in shoot and leaf tissues. Interestingly, wheat exhibited stronger expression of TaBDRO1-like than barley (HvDRO1-like), but TaBDRO1-like was the least expressing among three paralogs. The underlying cause of this expression divergence seems to be the presence of AuxRE motif TGTCTC and core TGTC with a coupling AuxRE-like motif ATTTTCTT proximal to the transcriptional start site in TaBDRO1-like and HvDRO1-like promoters. This is evident from binding of ARF1 to TGTCTC and TGTC motifs of TaBDRO1-like as revealed by yeast one-hybrid assay. Thus, evolution of DRO1-like wheat homoeologs might incorporate the C-terminus mutations as well as gain and loss of AuxREs and other cis-regulatory elements during expression divergence. Since root architecture is an important target trait for wheat crop improvement, therefore DRO1-like genes have potential applications in plant breeding for enhancement of plant productivity by the use of modern genome editing approaches.


Assuntos
Evolução Molecular , Ácidos Indolacéticos/farmacologia , Mutação/genética , Proteínas de Plantas/química , Proteínas de Plantas/genética , Elementos de Resposta/genética , Homologia de Sequência de Aminoácidos , Triticum/genética , Motivos de Aminoácidos , Sequência de Aminoácidos , Sequência de Bases , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Hordeum/anatomia & histologia , Hordeum/efeitos dos fármacos , Íntrons/genética , Proteínas de Plantas/metabolismo , Raízes de Plantas/anatomia & histologia , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/genética , Regiões Promotoras Genéticas , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Triticum/anatomia & histologia , Triticum/efeitos dos fármacos
7.
Plant Cell Physiol ; 60(6): 1342-1353, 2019 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-30994893

RESUMO

Spike brittleness represents an important domestication trait in crops. Although the brittle rachis of wild wheat was cloned, however, the molecular mechanism underlying spike brittleness is yet to be elucidated. Here, we identified a single dominant brittle rachis gene Br-Ab on chromosome arm 3AbS using an F2 population of diploid wheat and designated Btr1-Ab. Sequence analysis of the Btr1-A gene in 40 diploid wheat accessions, 80 tetraploid wheat accessions and 38 hexaploid wheat accessions showed that two independent mutations (Ala119Thr for diploid and Gly97* for polyploids) in the Btr1-A coding region resulting in the nonbrittle rachis allele. Overexpression of Btr1-Ab in nonbrittle hexaploid wheat led to brittle rachis in transgenic plants. RNA-Seq analysis revealed that Btr1-A represses the expression of cell wall biosynthesis genes during wheat rachis development. In addition, we found that Btr1-A can modify spike morphology and reduce threshability, grain size and thousand grain weight in transgenic wheat. These results demonstrated that Btr1-A reduces cell wall synthesis in rachis nodes, resulting in natural spikelet shattering, and that the transition from Btr1-A to btr1-A during wheat domestication had profound effects on evolution of spike morphology and yield-related traits.


Assuntos
Grão Comestível/crescimento & desenvolvimento , Proteínas de Plantas/fisiologia , Triticum/crescimento & desenvolvimento , Alelos , Parede Celular/metabolismo , Diploide , Grão Comestível/anatomia & histologia , Grão Comestível/ultraestrutura , Genes de Plantas/genética , Genes de Plantas/fisiologia , Microscopia Eletrônica de Varredura , Proteínas de Plantas/genética , Plantas Geneticamente Modificadas , Poliploidia , Característica Quantitativa Herdável , Análise de Sequência de DNA , Tetraploidia , Triticum/anatomia & histologia , Triticum/genética , Triticum/ultraestrutura
8.
Theor Appl Genet ; 132(8): 2181-2193, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31020386

RESUMO

KEY MESSAGE: Tiller development in low-tillering wheat is related to several differentially expressed genes, proteins, and metabolites, as determined by an integrated omics approach combining transcriptome analysis, iTRAQ, and HPLC-MS on multiple NILs. Tillering is an important aspect of plant morphology that affects spike number, thereby contributing to the final crop yield. However, the mechanisms inhibiting tiller production in low-tillering wheat are poorly characterized. To investigate this aspect of wheat biology, two pairs of near-isogenic lines were developed, and an integrated omics approach combining transcriptome analysis, isobaric tags for relative and absolute quantification, and high-performance liquid chromatography-mass spectrometry were used to compare the free-tillering and low-tillering caused by an allele at Qltn.sicau-2D in wheat samples. Overall, 474 genes, 166 proteins, and 28 metabolites were identified as tillering-associated differentially expressed genes, proteins, and metabolites (DEGs, DEPs, and DEMs, respectively). Functional analysis indicated that the abundance of DEGs/DEPs/DEMs was related to lignin and cellulose metabolism, cell division, cell cycle processes, and glycerophospholipid metabolism; three transcription factor families, GRAS, GRF, and REV, might be related to the decrease in tillering in low-tillering wheat. These findings contribute to improve our understanding of the mechanisms responsible for the inhibition of tiller development in low-tillering wheat cultivars.


Assuntos
Metabolômica , Proteômica , Transcriptoma/genética , Triticum/anatomia & histologia , Triticum/metabolismo , Regulação da Expressão Gênica de Plantas , Variação Genética , Endogamia , Marcação por Isótopo , Metaboloma , Fenótipo , Proteoma/metabolismo , Triticum/genética
9.
BMC Genet ; 20(1): 23, 2019 02 28.
Artigo em Inglês | MEDLINE | ID: mdl-30819111

RESUMO

BACKGROUND: Common wheat (Triticum aestivum L.) is one of the most important food crops worldwide. Wheat spike-layer uniformity related traits (SLURTs) were complex traits that directly affect yield potential and appearance. In this study, quantitative trait locus (QTL) for five SLURTs among inter-tillers were first documented using a recombinant inbred line (RIL) mapping population derived from a cross between Kenong9204 and Jing411 (represented by KJ-RILs). Genetic relationships between SLURTs and yield were characterized in detail. RESULTS: The trait phenotypic performances for the 188 KJ-RILs and their parents were evaluated in eight different environments. The genetic data included in a high-density genetic map derived from the Affymetrix 660 K SNP Array and the corresponding genotypes in each lines. Of 99 putative additive QTL 11 were stable across environments and 57 showed significant additive-by-environment interaction effects. These QTL individually explained 1.05-39.62% of the phenotypic variance, with log of odds (LOD) values ranging from 2.00 to 34.01. Genetic relationships between SLURTs and yield indicated that plants with slight uneven spike spatial distribution should be an ideotype for super high-yield in wheat. CONCLUSIONS: The present study will provide assistance in understanding the genetic relationships between SLURTs and yield potential. The 11 stable QTL for SLURTs identified herein may facilitate breeding new wheat varieties with scientifically reasonable spike-layer distribution by marker assisted selection.


Assuntos
Locos de Características Quantitativas/genética , Triticum/anatomia & histologia , Triticum/genética , Cruzamento , Fenótipo , Triticum/crescimento & desenvolvimento
10.
Molecules ; 24(5)2019 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-30866466

RESUMO

Red coleoptiles can help crops to cope with adversity and the key genes that are responsible for this trait have previously been isolated from Triticum aestivum, Triticum urartu, and Aegilops tauschii. This report describes the use of transcriptome analysis to determine the candidate gene that controls the trait for white coleoptiles in T. monococcum by screening three cultivars with white coleoptiles and two with red coleoptiles. Fifteen structural genes and two transcription factors that are involved in anthocyanin biosynthesis were identified from the assembled UniGene database through BLAST analysis and their transcript levels were then compared in white and red coleoptiles. The majority of the structural genes reflected lower transcript levels in the white than in the red coleoptiles, which implied that transcription factors related to anthocyanin biosynthesis could be candidate genes. The transcript levels of MYC transcription factor TmMYC-A1 were not significantly different between the white and red coleoptiles and all of the TmMYC-A1s contained complete functional domains. The deduced amino acid sequence of the MYB transcription factor TmMYB-A1 in red coleoptiles was homologous to TuMYB-A1, TaMYB-A1, TaMYB-B1, and TaMYB-D1, which control coleoptile color in corresponding species and contained the complete R2R3 MYB domain and the transactivation domain. TmMYB-a1 lost its two functional domains in white coleoptiles due to a single nucleotide deletion that caused premature termination at 13 bp after the initiation codon. Therefore, TmMYB-A1 is likely to be the candidate gene for the control of the red coleoptile trait, and its loss-of-function mutation leads to the white phenotype in T. monococcum.


Assuntos
Cotilédone/genética , Perfilação da Expressão Gênica/métodos , Fatores de Transcrição/genética , Triticum/anatomia & histologia , Antocianinas/biossíntese , Cotilédone/anatomia & histologia , Regulação da Expressão Gênica de Plantas , Sequenciamento de Nucleotídeos em Larga Escala , Mutação , Proteínas de Plantas/genética , Locos de Características Quantitativas , Análise de Sequência de RNA , Triticum/genética
11.
Gigascience ; 8(3)2019 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-30715329

RESUMO

BACKGROUND: High-quality plant phenotyping and climate data lay the foundation for phenotypic analysis and genotype-environment interaction, providing important evidence not only for plant scientists to understand the dynamics between crop performance, genotypes, and environmental factors but also for agronomists and farmers to closely monitor crops in fluctuating agricultural conditions. With the rise of Internet of Things technologies (IoT) in recent years, many IoT-based remote sensing devices have been applied to plant phenotyping and crop monitoring, which are generating terabytes of biological datasets every day. However, it is still technically challenging to calibrate, annotate, and aggregate the big data effectively, especially when they were produced in multiple locations and at different scales. FINDINGS: CropSight is a PHP Hypertext Pre-processor and structured query language-based server platform that provides automated data collation, storage, and information management through distributed IoT sensors and phenotyping workstations. It provides a two-component solution to monitor biological experiments through networked sensing devices, with interfaces specifically designed for distributed plant phenotyping and centralized data management. Data transfer and annotation are accomplished automatically through an hypertext transfer protocol-accessible RESTful API installed on both device side and server side of the CropSight system, which synchronize daily representative crop growth images for visual-based crop assessment and hourly microclimate readings for GxE studies. CropSight also supports the comparison of historical and ongoing crop performance while different experiments are being conducted. CONCLUSIONS: As a scalable and open-source information management system, CropSight can be used to maintain and collate important crop performance and microclimate datasets captured by IoT sensors and distributed phenotyping installations. It provides near real-time environmental and crop growth monitoring in addition to historical and current experiment comparison through an integrated cloud-ready server system. Accessible both locally in the field through smart devices and remotely in an office using a personal computer, CropSight has been applied to field experiments of bread wheat prebreeding since 2016 and speed breeding since 2017. We believe that the CropSight system could have a significant impact on scalable plant phenotyping and IoT-style crop management to enable smart agricultural practices in the near future.


Assuntos
Produtos Agrícolas/anatomia & histologia , Internet , Software , Microclima , Fenótipo , Triticum/anatomia & histologia
12.
Proc Natl Acad Sci U S A ; 116(11): 5182-5187, 2019 03 12.
Artigo em Inglês | MEDLINE | ID: mdl-30792353

RESUMO

Floret fertility is a key determinant of the number of grains per inflorescence in cereals. During the evolution of wheat (Triticum sp.), floret fertility has increased, such that current bread wheat (Triticum aestivum) cultivars set three to five grains per spikelet. However, little is known regarding the genetic basis of floret fertility. The locus Grain Number Increase 1 (GNI1) is shown here to be an important contributor to floret fertility. GNI1 evolved in the Triticeae through gene duplication. The gene, which encodes a homeodomain leucine zipper class I (HD-Zip I) transcription factor, was expressed most abundantly in the most apical floret primordia and in parts of the rachilla, suggesting that it acts to inhibit rachilla growth and development. The level of GNI1 expression has decreased over the course of wheat evolution under domestication, leading to the production of spikes bearing more fertile florets and setting more grains per spikelet. Genetic analysis has revealed that the reduced-function allele GNI-A1 contributes to the increased number of fertile florets per spikelet. The RNAi-based knockdown of GNI1 led to an increase in the number of both fertile florets and grains in hexaploid wheat. Mutants carrying an impaired GNI-A1 allele out-yielded WT allele carriers under field conditions. The data show that gene duplication generated evolutionary novelty affecting floret fertility while mutations favoring increased grain production have been under selection during wheat evolution under domestication.


Assuntos
Fertilidade/genética , Flores/genética , Flores/fisiologia , Genes Homeobox , Mutação/genética , Triticum/genética , Triticum/fisiologia , Alelos , Clonagem Molecular , Evolução Molecular , Flores/anatomia & histologia , Regulação da Expressão Gênica de Plantas , Genes de Plantas , Variação Genética , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Ploidias , Locos de Características Quantitativas/genética , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Triticum/anatomia & histologia
13.
J Integr Plant Biol ; 61(3): 278-295, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30609316

RESUMO

Grass species display a wide array of inflorescences ranging from highly branched compound/panicle inflorescences to unbranched spike inflorescences. The unbranched spike is a characteristic feature of the species of tribe Triticeae, including economically important crops, such as wheat and barley. In this review, we describe two important developmental genetic mechanisms regulating spike inflorescence architecture in barley and wheat. These include genetic regulation of (i) row-type pathway specific to Hordeum species and (ii) unbranched spike development in barley and wheat. For a comparative understanding, we describe the branched inflorescence phenotypes of rice and maize along with unbranched Triticeae inflorescences. In the end, we propose a simplified model describing a probable mechanism leading to unbranched spike formation in Triticeae species.


Assuntos
Hordeum/anatomia & histologia , Hordeum/crescimento & desenvolvimento , Inflorescência/crescimento & desenvolvimento , Desenvolvimento Vegetal , Triticum/anatomia & histologia , Triticum/crescimento & desenvolvimento , Evolução Biológica , Hordeum/genética , Meristema/crescimento & desenvolvimento , Triticum/genética
14.
Planta ; 249(3): 839-847, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30446814

RESUMO

MAIN CONCLUSION: Density and length of leaf pubescence are important factors of diversity in the response to water deficiency among wheat genotypes. Many studies evidence an important protective value of leaf hairiness in plants, especially under the conditions of drought, thermal loads and increased solar radiation. However, the physiological and adaptive roles of such traits in cereals, including cultivated plants, have not been sufficiently studied to date. The aim of this work was to study the association of morphological characteristics of leaves with parameters of gas exchange and chlorophyll fluorescence in wheat lines carrying a genetically different leaf hairiness. Isogenic and inter-varietal substitution wheat lines were used, carrying various combinations of dominant and recessive alleles of the known genes. A quantitative assessment of the pubescence was carried out in contrasting watering conditions to establish the physiological role of this trait in adaptation to drought. With the help of a portable system for studying the gas exchange and chlorophyll fluorescence, ten parameters of photosynthesis were studied, as well as morphological features of leaves and shoot biomass. It was found that gas exchange parameters are inversely proportional to the density and length of trichomes. In drought conditions, the trichome density increased and the length of trichomes decreased under the observed decrease in the level of gas exchange. A similar dependence was observed for the level of non-photochemical quenching of chlorophyll fluorescence. Under optimal conditions, the poorly haired cultivars exhibited a higher biomass than the densely haired. However, under water deficiency they significantly reduced the biomass and showed a low value of the tolerance index.


Assuntos
Fotossíntese , Folhas de Planta/anatomia & histologia , Triticum/anatomia & histologia , Clorofila/metabolismo , Desidratação , Fotossíntese/fisiologia , Folhas de Planta/fisiologia , Característica Quantitativa Herdável , Triticum/genética , Triticum/fisiologia
15.
J Integr Plant Biol ; 61(3): 296-309, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30325110

RESUMO

Modifications of inflorescence architecture have been crucial for the successful domestication of wheat and barley, which are central members of the Triticeae tribe that provide essential grains for the human diet. Investigation of the genes and alleles that underpin domestication-related traits has provided valuable insights into the molecular regulation of inflorescence development of the Triticeae, and further investigation of modified forms of architecture are proving to be equally fruitful. The identified genes are involved in diverse biological processes, including transcriptional regulation, hormone biosynthesis and metabolism, post-transcriptional and post-translational regulation, which alter inflorescence architecture by modifying the development and fertility of lateral organs, called spikelets and florets. Recent advances in sequencing capabilities and the generation of mutant populations are accelerating the identification of genes that influence inflorescence development, which is important given that genetic variation for this trait promises to be a valuable resource for optimizing grain production. This review assesses recent advances in our understanding of the genes controlling inflorescence development in wheat and barley, with the aim of highlighting the importance of improvements in developmental biology for optimizing the agronomic performance of staple crop plants.


Assuntos
Hordeum/anatomia & histologia , Hordeum/genética , Inflorescência/genética , Triticum/anatomia & histologia , Triticum/genética , Sequência de Bases , Domesticação , Genes de Plantas , Fenótipo
16.
Plant Cell Environ ; 42(2): 509-526, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30160775

RESUMO

Fusarium head blight, caused primarily by Fusarium graminearum (Fg), is one of the most devastating diseases of wheat. Host resistance in wheat is classified into five types (Type-I to Type-V), and a majority of moderately resistant genotypes carry Type-II resistance (resistance to pathogen spread in the rachis) alleles, mainly from the Chinese cultivar Sumai 3. Histopathological studies in the past failed to identify the key tissue in the spike conferring resistance to pathogen spread, and most of the studies used destructive techniques, potentially damaging the tissue(s) under study. In the present study, nondestructive synchrotron-based phase contrast X-ray imaging and computed tomography techniques were used to confirm the part of the wheat spike conferring Type-II resistance to Fg spread, thus showcasing the application of synchrotron-based techniques to image host-pathogen interactions. Seven wheat genotypes of moderate resistance to Fusarium head blight were studied for changes in the void space volume fraction and grayscale/voxel intensity following Fg inoculation. Cell-wall biopolymeric compounds were quantified using Fourier-transform midinfrared spectroscopy for all genotype-treatment combinations. The study revealed that the rachilla and rachis nodes together are structurally important in conferring Type-II resistance. The structural reinforcement was not necessarily observed from lignin deposition but rather from an unknown mechanism.


Assuntos
Resistência à Doença , Fusarium , Interações Hospedeiro-Patógeno , Doenças das Plantas/microbiologia , Caules de Planta/anatomia & histologia , Triticum/imunologia , Doenças das Plantas/imunologia , Caules de Planta/microbiologia , Espectroscopia de Infravermelho com Transformada de Fourier , Síncrotrons , Tomografia Computadorizada por Raios X , Triticum/anatomia & histologia , Triticum/microbiologia
17.
Plant Physiol Biochem ; 135: 480-488, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30463800

RESUMO

The aim of this study was to assess some physiological parameters and anatomical changes in two wheat plant cultivars (Triticum aestivum L. cvs. Sakha 93 and Sids 9) in response to irrigation with magnetized water under two levels of drought stress (field capacity (FC) of 75% and 50%) and the control (FC 100%) in two consecutive winter growing seasons (November 20 to May 5 2014/2015 and 2015/2016). Pot experiments were carried out in a greenhouse in the experimental farm of the Faculty of Agriculture, Menoufia University, Shibin El-Kom, Egypt. A water deficit, particularly at 50% FC, significantly decreased growth and parameter values, above all in Sakha 93, and disrupted most physiological aspects, biochemical constituents and internal structural features of both wheat cultivars. Irrigation with magnetized water alleviated the negative consequences of drought stress on most physiological and biochemical parameters to a variable extent: the whole plant dry weight, total water content, total soluble sugar concentration in leaves, total free amino acids and proline increased by about 32, 12, 17, 27 and 73%, respectively, under 50% FC drought stress in Sids 9 compared to the control. As the levels of drought increased, the grain yield (g/plant) decreased considerably, from about 81% in Sakha 93 at 50% FC to 26% in Sids 9 at 75% FC. The use of magnetic water increased grain yield from 61% in Sakha 93 at 75% FC to about 268% in Sids 9 at 50% FC. Magnetic water also increased the thickness of the flag leaf midvein and lamina, as well as the metaxylem vessel diameter of Sakha 93 by 28.8, 11.7 and 20.0%, respectively, compared to the control. The application of magnetic water increased the growth and the other parameter values studied in both cultivars but above all in Sakha 93, whereas Sids 9 produced more grain yield under all levels of drought stress. As the growth and grain production increased in both cultivars when using magnetic water, this study recommends this type of irrigation for these wheat plants, which are widespread in Egypt.


Assuntos
Irrigação Agrícola/métodos , Triticum/fisiologia , Desidratação , Magnetismo , Triticum/anatomia & histologia , Triticum/crescimento & desenvolvimento , Água
18.
Sci Total Environ ; 654: 633-642, 2019 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-30447601

RESUMO

The partitioning of evapotranspiration (ET) into soil evaporation (E) and crop transpiration (T) is fundamental for accurately monitoring agro-hydrological processes, assessing crop productivity, and optimizing water management practices. In this study, the isotope tracing technique was used to partition ET of winter wheat under different irrigation (100, 160 and 240 mm) and fertilization (105, 210 and 315 kg N ha-1) treatments during the 2014 and 2015 growing seasons in Beijing, China. The correlations between seasonal ET partitioning and the leaf area index (LAI), grain yield, and water use efficiency (WUE, ratio of crop yield and ET) were investigated and agricultural management practices were optimized. The fraction of T in ET (FT) between the greening and harvest seasons was 0.82 on average and did not vary significantly among the treatments (p > 0.05). However, the values of FT during the individual growth periods ranged from 0.51 to 0.98, and they were remarkably distinct for all treatments. The seasonal variability in FT could be effectively explained via a power-law function of the LAI (FT = 0.61 LAI0.21, R2 = 0.66, p < 0.01). There was no significant relationship between FT and the grain yield or WUE (p > 0.05). The total T during the jointing-heading and heading-filling periods (Tjf) had significantly quadratic relationships with the crop yield and WUE (p < 0.01). Both the crop yield and the WUE had high values under the Tjf range of 117.5-155.8 mm. Furthermore, the WUE was higher under larger ratio of E in ET (FE) during the greening-jointing period and lower FE during the filling-harvest period. Two irrigations during the greening-jointing (20 mm) and heading-filling (80 mm) stages and one fertilization (105 kg ha-1 N) during the greening-jointing stage were determined as appropriate irrigation and fertilization schedules.


Assuntos
Irrigação Agrícola , Produção Agrícola/métodos , Fertilizantes/análise , Transpiração Vegetal , Triticum/crescimento & desenvolvimento , Triticum/metabolismo , Folhas de Planta/anatomia & histologia , Estações do Ano , Triticum/anatomia & histologia , Água/metabolismo
19.
Plant Biol (Stuttg) ; 21 Suppl 1: 84-94, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29444373

RESUMO

Temperate grasses, such as wheat, become compact plants with small thick leaves after exposure to low temperature. These responses are associated with cold hardiness, but their underlying mechanisms remain largely unknown. Here we analyse the effects of low temperature on leaf morpho-anatomical structure, cell wall composition and activity of extracellular peroxidases, which play key roles in cell elongation and cell wall thickening, in two wheat cultivars with contrasting cold-hardening ability. A combined microscopy and biochemical approach was applied to study actively growing leaves of winter (ProINTA-Pincén) and spring (Buck-Patacón) wheat developed under constant warm (25 °C) or cool (5 °C) temperature. Cold-grown plants had shorter leaves but longer inter-stomatal epidermal cells than warm-grown plants. They had thicker walls in metaxylem vessels and mestome sheath cells, paralleled with accumulation of wall components, predominantly hemicellulose. These effects were more pronounced in the winter cultivar (Pincén). Cold also induced a sharp decrease in apoplastic peroxidase activity within the leaf elongating zone of Pincén, and a three-fold increase in the distal mature zone of the leaf. This was consistent with the enhanced cell length and thicker cell walls in this cultivar at 5 °C. The different response to low temperature of apoplastic peroxidase activity and hemicellulose between leaf zones and cultivar types suggests they might play a central role in the development of cold-induced compact morphology and cold hardening. New insights are presented on the potential temperature-driven role of peroxidases and hemicellulose in cell wall dynamics of grasses.


Assuntos
Parede Celular/metabolismo , Temperatura Baixa , Peroxidase/metabolismo , Folhas de Planta/anatomia & histologia , Folhas de Planta/fisiologia , Triticum/anatomia & histologia , Triticum/fisiologia , Proteínas de Plantas/metabolismo , Polissacarídeos/metabolismo , Estações do Ano
20.
Funct Integr Genomics ; 19(1): 29-41, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29968001

RESUMO

Particularly PIN1, PIN protein-mediated rate-limiting auxin distribution plays a critical role in plant differentiation. Although well-characterized in Arabidopsis, little is known about the structural and functional relationship of the PIN1 gene among other plants. Here, we report that the gene structure remained conserved among bryophytes and angiosperms while the gene size varied by ~ 17%. Although the positions were conserved, highly variable intron phase suggests preference for specific regions in the gene sequence for independent events of intron insertion. Significant variation was observed across gene length for insertions and deletions that were mainly localized to the exonic regions flanking intron 1, possibly demarcating the sequences prone to deletions/duplications. The N and C-terminals showed a higher protein sequence similarity (~ 80%) compared to the central hydrophilic loop (~ 26%). In addition to the signature domains and motifs, we identified four novel uncharacterized motifs in the central divergent loop of PIN1 protein. Three different homo-loci, one each on chromosome groups 4, 6, and 7, were identified in wheat each showing dramatically different expression patterns during different plant developmental stages. Virus-induced gene silencing of the TaPIN1 gene resulted up to 26% reduction in plant height. Because of its direct role in controlling plant height along with a higher expression during stem elongation, the TaPIN1 gene can be manipulated to regulate plant height.


Assuntos
Proteínas de Arabidopsis/genética , Evolução Molecular , Regulação da Expressão Gênica no Desenvolvimento , Regulação da Expressão Gênica de Plantas , Ácidos Indolacéticos/metabolismo , Proteínas de Membrana Transportadoras/genética , Triticum/genética , Motivos de Aminoácidos , Arabidopsis/anatomia & histologia , Arabidopsis/classificação , Arabidopsis/genética , Arabidopsis/crescimento & desenvolvimento , Proteínas de Arabidopsis/antagonistas & inibidores , Proteínas de Arabidopsis/metabolismo , Sequência de Bases , Transporte Biológico , Sequência Conservada , Éxons , Dosagem de Genes , Íntrons , Proteínas de Membrana Transportadoras/metabolismo , Mutação , Oligonucleotídeos/genética , Oligonucleotídeos/metabolismo , Fases de Leitura Aberta , Filogenia , Caules de Planta/anatomia & histologia , Caules de Planta/genética , Caules de Planta/crescimento & desenvolvimento , Vírus de Plantas/genética , Vírus de Plantas/metabolismo , Plasmídeos/química , Plasmídeos/metabolismo , Alinhamento de Sequência , Homologia de Sequência do Ácido Nucleico , Triticum/anatomia & histologia , Triticum/classificação , Triticum/crescimento & desenvolvimento
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